B — https://spring.io | BeaverCheck Audit

Site Health

Score: 80 / 100

Based on 8 categories, 0 sections

How is this calculated?

The overall score is a weighted average of individual category scores. Categories with more impact on user experience and security carry more weight.

Performance 25%Security 25%Accessibility 15%SEO 10%Infrastructure 10%Compliance 8%Content 5%Sustainability 2%

Weights reflect general web best practices. Individual needs may differ.

Top Priorities (5)

Content-Security-Policy header is missing

Security › Security Headers

No Content-Security-Policy header found

Security › Content Security Policy

1 link(s) with no accessible text

Accessibility › Link & Button Quality

Cookie '__cf_bm' has no SameSite attribute

Security › Cookie Security

Cross-Origin-Embedder-Policy header is missing

Security › Security Headers

Embed this badge

Markdown

[![BeaverCheck](https://beavercheck.com/badge?url=https%3A%2F%2Fspring.io)](https://beavercheck.com/results/e2cd0fc7-2820-4e9b-b568-4bd491d41faa)

HTML

<a href="https://beavercheck.com/results/e2cd0fc7-2820-4e9b-b568-4bd491d41faa"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fspring.io" alt="BeaverCheck Score"></a>

Image URL

https://beavercheck.com/badge?url=https%3A%2F%2Fspring.io

This badge auto-updates with your latest scan result.

Was this report useful?

Thanks for your feedback!

Press ? for shortcuts

Lighthouse Scores

Industry-standard audits powered by Google Lighthouse.

Performance

Accessibility

Best Practices

SEO

Core Web Vitals

Key metrics that affect user experience.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

1.94 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

5.69 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

274 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.001

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

2.67 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

5.81 s

Detailed Report

Audit breakdown by category with detailed findings.

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Request	Cache TTL	Transfer Size
cdn.cookielaw.org/scripttemplates/202509.1.0/otBannerSdk.js	86400.0 s	121.6 KiB
/logos/8153b982-ae11-46a0-b7c2-6e4e3b591d72/22e2df79-991e...	86400.0 s	56.1 KiB
spring.io/fonts/work-sans-v5-latin/work-sans-v5-latin-regular.woff2	3600.0 s	22.2 KiB
spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-700.woff2	3600.0 s	15.0 KiB
spring.io/fonts/metropolis/metropolis-bold-webfont.woff2	3600.0 s	14.8 KiB
spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-600.woff2	3600.0 s	14.8 KiB
spring.io/fonts/metropolis/metropolis-extrabold-webfont.woff2	3600.0 s	14.7 KiB
spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-regular.woff2	3600.0 s	14.3 KiB
static.cloudflareinsights.com/beacon.min.js	86400.0 s	10.7 KiB
/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312...	86400.0 s	10.7 KiB
spring.io/img/icons/ai.svg	3600.0 s	5.0 KiB
cdn.cookielaw.org/scripttemplates/otSDKStub.js	86400.0 s	9.1 KiB
spring.io/img/icons/reactive.svg	3600.0 s	4.2 KiB
spring.io/img/extra/bakker-120.jpg	3600.0 s	3.2 KiB
spring.io/img/icons/batch.svg	3600.0 s	1.7 KiB
spring.io/img/icons/cloud.svg	3600.0 s	1.3 KiB
spring.io/img/icons/event-driven.svg	3600.0 s	1.1 KiB
cdn.cookielaw.org/logos/static/powered_by_logo.svg	86400.0 s	2.1 KiB
spring.io/img/icons/microservices.svg	3600.0 s	1.0 KiB
spring.io/img/icons/web-apps.svg	3600.0 s	994 B
spring.io/img/icons/serverless.svg	3600.0 s	987 B
spring.io/img/extra/footer.svg	3600.0 s	581 B
spring.io/img/extra/quote.svg	3600.0 s	558 B
cdn.cookielaw.org/logos/static/ot_close.svg	86400.0 s	608 B

A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:36.031 source:map[type:text value:[unattributed]]]]

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.

title: Preconnected origins

value: no origins were preconnected

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

URL	Transfer Size	Duration
cdn.cookielaw.org/scripttemplates/otSDKStub.js	9.1 KiB	764 ms

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

TTI

The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.

Diagnostics

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Estimated savings: 300 ms 138.2 KiB

URL	Transfer Size	Est Savings
www.googletagmanager.com/gtm.js?id=GTM-W8CQ8TL	132.5 KiB	74.0 KiB
cdn.cookielaw.org/scripttemplates/202509.1.0/otBannerSdk.js	121.4 KiB	64.2 KiB

Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work

Category	Time Spent
Script Evaluation	1.1 s
Other	818 ms
Style & Layout	522 ms
Script Parsing & Compilation	202 ms
Parse HTML & CSS	158 ms
Rendering	118 ms

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Estimated savings: 0.0 ms 68.5 KiB

URL	Transfer Size	Est Savings
/*! bulma.io v0.9.4 \| MIT License \| github.com/jgthms/bul...	52.0 KiB	49.2 KiB
	22.4 KiB	19.3 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

	URL
Quote `div#main > div.container > div.testimony > img.testimony-quote`	spring.io/img/extra/quote.svg

More information about the performance of your application. These numbers don't directly affect the Performance score.

●Layout shift culprits

●Document request latency

●Optimize DOM size

●Font display

●Improve image delivery

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 693 KiB

●User Timing marks and measures 1 user timing

●JavaScript execution time 1.2 s

●Avoid long main-thread tasks 11 long tasks found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 10 ms

●Server Backend Latencies 70 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 80 ms

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○LCP request discovery

○Avoid non-composited animations

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

ARIA

Some ARIA child roles must be contained by specific parent roles to properly perform their intended accessibility functions. Learn more about ARIA roles and required parent element.

Failing Elements
nav#header > div.container > div.navbar-brand > div.navbar-burger `nav#header > div.container > div.navbar-brand > div.navbar-burger`

When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn how to make command elements more accessible.

Failing Elements
nav#header > div.container > div.navbar-brand > div.navbar-burger `nav#header > div.container > div.navbar-brand > div.navbar-burger`
div.container > div.navbar-brand > div.navbar-burger > div.hamburger-react `div.container > div.navbar-brand > div.navbar-burger > div.hamburger-react`

These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Failing Elements
Most [of our] services today are all based on Spring Boot. I think the most imp… `div#main > div.container > div.testimony > div.testimony-text`
Apache®, Apache Tomcat®, Apache Kafka®, Apache Cassandra™, and Apache Geode™ ar… `div.container > div.columns > div.column > p.has-text-grey-light`
Cookie Notice. `div.ot-sdk-eight > div#onetrust-policy > div#onetrust-policy-text > a.ot-cookie-policy-link`

These are opportunities to improve the legibility of your content.

Names and labels

Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn how to make links accessible.

Failing Elements
div#gatsby-focus-wrapper > div > div.anchor-to-header > a.animate-anchor `div#gatsby-focus-wrapper > div > div.anchor-to-header > a.animate-anchor`

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

Best practices

Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.

Failing Elements
nav#header > div.container > div.navbar-brand > div.navbar-burger `nav#header > div.container > div.navbar-brand > div.navbar-burger`

These items highlight common accessibility best practices.

Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.

Failing Elements
Learn more `div.container > div.columns > article.column > a.is-link`
Learn more `div.container > div.columns > article.column > a.is-link`
View all `div.container > div.columns > article.column > a.is-link`
Cookie Notice. `div.ot-sdk-eight > div#onetrust-policy > div#onetrust-policy-text > a.ot-cookie-policy-link`

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

●ARIA attributes are used as specified for the element's role

●Elements with `role="dialog"` or `role="alertdialog"` have accessible names.

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Document has a `<title>` element

●`<html>` element has a `[lang]` attribute

●`<html>` element has a valid value for its `[lang]` attribute

●Links are distinguishable without relying on color.

●No element has a `[tabindex]` value greater than 0

●Heading elements appear in a sequentially-descending order

●Skip links are focusable.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Uses ARIA roles only on compatible elements

○`[accesskey]` values are unique

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.

○Elements with the `role=text` attribute do not have focusable descendents.

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

○The page contains a heading, skip link, or landmark region

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

○`<frame>` or `<iframe>` elements have a title

○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.

○Input buttons have discernible text.

○`<input type="image">` elements have `[alt]` text

○Form elements have associated labels

○Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

○List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

○The document does not use `<meta http-equiv="refresh">`

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

○`[lang]` attributes have a valid value

○`<video>` elements contain a `<track>` element with `[kind="captions"]`

○Tables have different content in the summary attribute and `<caption>`.

○All heading elements contain content.

○Image elements do not have `[alt]` attributes that are redundant text.

○Identical links have the same purpose.

○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.

○`<td>` elements in a large `<table>` have one or more table headers.

Best Practices

General

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Source	Description
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 121490	Error: Minified React error #423; visit https://reactjs.org/docs/error-decoder.html?invariant=423 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121491) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at as (https://spring.io/framework-f0de980621661f0b7a47.js:2:106001) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104556) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 44356	Error: Minified React error #425; visit https://reactjs.org/docs/error-decoder.html?invariant=425 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at Zr (https://spring.io/framework-f0de980621661f0b7a47.js:2:44357) at qo (https://spring.io/framework-f0de980621661f0b7a47.js:2:85555) at ks (https://spring.io/framework-f0de980621661f0b7a47.js:2:109696) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109436) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)

Issues logged to the `Issues` panel in Chrome Devtools indicate unresolved problems. They can come from network request failures, insufficient security controls, and other browser concerns. Open up the Issues panel in Chrome DevTools for more details on each issue.

Issue type
Content security policy

●Uses HTTPS

●Avoids deprecated APIs

●Avoids third-party cookies

●Allows users to paste into input fields

●Avoids requesting the geolocation permission on page load

●Avoids requesting the notification permission on page load

●Displays images with correct aspect ratio

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

●Ensure CSP is effective against XSS attacks

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

●Page has valid source maps

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

SEO

These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.

Content Best Practices

Descriptive link text helps search engines understand your content. Learn how to make links more accessible.

Link destination	Link Text
spring.academy/	Learn more
spring.io/support	Learn more

Format your HTML in a way that enables crawlers to better understand your app’s content.

○Structured data is valid

●Page isn’t blocked from indexing

●Document has a `<title>` element

●Document has a meta description

●Page has successful HTTP status code

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`

Lighthouse Scores

Industry-standard audits powered by Google Lighthouse. — Desktop

Performance

Accessibility

Best Practices

SEO

Core Web Vitals

Key metrics that affect user experience. — Desktop

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

590 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

1.22 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

0 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.008

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

858 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.23 s

Detailed Report

Audit breakdown by category with detailed findings.

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Request	Cache TTL	Transfer Size
cdn.cookielaw.org/scripttemplates/202509.1.0/otBannerSdk.js	86400.0 s	121.6 KiB
/logos/8153b982-ae11-46a0-b7c2-6e4e3b591d72/22e2df79-991e...	86400.0 s	56.1 KiB
spring.io/fonts/work-sans-v5-latin/work-sans-v5-latin-regular.woff2	3600.0 s	22.2 KiB
spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-700.woff2	3600.0 s	15.0 KiB
spring.io/fonts/metropolis/metropolis-bold-webfont.woff2	3600.0 s	14.8 KiB
spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-600.woff2	3600.0 s	14.8 KiB
spring.io/fonts/metropolis/metropolis-extrabold-webfont.woff2	3600.0 s	14.7 KiB
spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-regular.woff2	3600.0 s	14.3 KiB
static.cloudflareinsights.com/beacon.min.js	86400.0 s	10.7 KiB
/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312...	86400.0 s	10.7 KiB
spring.io/img/icons/ai.svg	3600.0 s	5.0 KiB
cdn.cookielaw.org/scripttemplates/otSDKStub.js	86400.0 s	9.1 KiB
spring.io/img/icons/reactive.svg	3600.0 s	4.2 KiB
spring.io/img/extra/bakker-120.jpg	3600.0 s	3.2 KiB
spring.io/img/icons/batch.svg	3600.0 s	1.7 KiB
spring.io/img/icons/cloud.svg	3600.0 s	1.3 KiB
spring.io/img/icons/event-driven.svg	3600.0 s	1.1 KiB
cdn.cookielaw.org/logos/static/powered_by_logo.svg	86400.0 s	2.1 KiB
spring.io/img/icons/microservices.svg	3600.0 s	1.0 KiB
spring.io/img/icons/web-apps.svg	3600.0 s	994 B
spring.io/img/icons/serverless.svg	3600.0 s	987 B
spring.io/img/extra/footer.svg	3600.0 s	581 B
spring.io/img/extra/quote.svg	3600.0 s	558 B
cdn.cookielaw.org/logos/static/ot_close.svg	86400.0 s	608 B

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:49.461 source:map[type:text value:[unattributed]]]]

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

title: Preconnected origins

value: no origins were preconnected

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

URL	Transfer Size	Duration
cdn.cookielaw.org/scripttemplates/otSDKStub.js	9.1 KiB	254 ms

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

Diagnostics

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Estimated savings: 0.0 ms 67.8 KiB

URL	Transfer Size	Est Savings
/*! bulma.io v0.9.4 \| MIT License \| github.com/jgthms/bul...	52.0 KiB	48.6 KiB
	22.4 KiB	19.2 KiB

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Estimated savings: 20 ms 138.2 KiB

URL	Transfer Size	Est Savings
www.googletagmanager.com/gtm.js?id=GTM-W8CQ8TL	132.5 KiB	74.0 KiB
cdn.cookielaw.org/scripttemplates/202509.1.0/otBannerSdk.js	121.4 KiB	64.2 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

	URL
Quote `div#main > div.container > div.testimony > img.testimony-quote`	spring.io/img/extra/quote.svg
div.default-banner > div.extra > div.extra-2 > img `div.default-banner > div.extra > div.extra-2 > img`	spring.io/img/extra/footer.svg

More information about the performance of your application. These numbers don't directly affect the Performance score.

●Layout shift culprits

●Document request latency

●Optimize DOM size

●Font display

●Improve image delivery

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Time to Interactive 1.2 s

●Max Potential First Input Delay 40 ms

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 694 KiB

●User Timing marks and measures 1 user timing

●JavaScript execution time 0.3 s

●Minimizes main-thread work 0.7 s

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 10 ms

●Server Backend Latencies 80 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 60 ms

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○LCP request discovery

○Avoid long main-thread tasks

○Avoid non-composited animations

Accessibility

ARIA

Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more about roles and required children elements.

Failing Elements
light `nav#header > div.container > div.navbar-menu > label.theme-toggler`

These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Failing Elements
Apache®, Apache Tomcat®, Apache Kafka®, Apache Cassandra™, and Apache Geode™ ar… `div.container > div.columns > div.column > p.has-text-grey-light`
Cookie Notice. `div.ot-sdk-eight > div#onetrust-policy > div#onetrust-policy-text > a.ot-cookie-policy-link`

These are opportunities to improve the legibility of your content.

Names and labels

Failing Elements
div#gatsby-focus-wrapper > div > div.anchor-to-header > a.animate-anchor `div#gatsby-focus-wrapper > div > div.anchor-to-header > a.animate-anchor`

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.

Failing Elements
Learn more `div.container > div.columns > article.column > a.is-link`
Learn more `div.container > div.columns > article.column > a.is-link`
View all `div.container > div.columns > article.column > a.is-link`
Cookie Notice. `div.ot-sdk-eight > div#onetrust-policy > div#onetrust-policy-text > a.ot-cookie-policy-link`

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●Form elements have associated labels

●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

●`button`, `link`, and `menuitem` elements have accessible names

●ARIA attributes are used as specified for the element's role

●Elements with `role="dialog"` or `role="alertdialog"` have accessible names.

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Document has a `<title>` element

●`<html>` element has a `[lang]` attribute

●`<html>` element has a valid value for its `[lang]` attribute

●Links are distinguishable without relying on color.

●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

●No element has a `[tabindex]` value greater than 0

●Touch targets have sufficient size and spacing.

●Heading elements appear in a sequentially-descending order

●Skip links are focusable.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Uses ARIA roles only on compatible elements

●Identical links have the same purpose.

○`[accesskey]` values are unique

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○`[role]`s are contained by their required parent element

○Elements with the `role=text` attribute do not have focusable descendents.

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

○The page contains a heading, skip link, or landmark region

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

○`<frame>` or `<iframe>` elements have a title

○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.

○Input buttons have discernible text.

○`<input type="image">` elements have `[alt]` text

○The document does not use `<meta http-equiv="refresh">`

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

○`[lang]` attributes have a valid value

○`<video>` elements contain a `<track>` element with `[kind="captions"]`

○Tables have different content in the summary attribute and `<caption>`.

○All heading elements contain content.

○Image elements do not have `[alt]` attributes that are redundant text.

○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.

○`<td>` elements in a large `<table>` have one or more table headers.

Best Practices

General

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Source	Description
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 49172	Error: Minified React error #418; visit https://reactjs.org/docs/error-decoder.html?invariant=418 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at sa (https://spring.io/framework-f0de980621661f0b7a47.js:2:49173) at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121805) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 121490	Error: Minified React error #423; visit https://reactjs.org/docs/error-decoder.html?invariant=423 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at xi (https://spring.io/framework-f0de980621661f0b7a47.js:2:121491) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109375) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at as (https://spring.io/framework-f0de980621661f0b7a47.js:2:106001) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104556) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)
spring.io/framework-f0de980621661f0b7a47.js line 1, col 44356	Error: Minified React error #425; visit https://reactjs.org/docs/error-decoder.html?invariant=425 for the full message or use the non-minified dev environment for full errors and additional helpful warnings. at Zr (https://spring.io/framework-f0de980621661f0b7a47.js:2:44357) at qo (https://spring.io/framework-f0de980621661f0b7a47.js:2:85555) at ks (https://spring.io/framework-f0de980621661f0b7a47.js:2:109696) at bs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109436) at vs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109303) at gs (https://spring.io/framework-f0de980621661f0b7a47.js:2:109166) at ls (https://spring.io/framework-f0de980621661f0b7a47.js:2:104329) at S (https://spring.io/framework-f0de980621661f0b7a47.js:2:137682) at MessagePort.T (https://spring.io/framework-f0de980621661f0b7a47.js:2:138214)

●Uses HTTPS

●Avoids deprecated APIs

●Avoids third-party cookies

●Allows users to paste into input fields

●Avoids requesting the geolocation permission on page load

●Avoids requesting the notification permission on page load

●Displays images with correct aspect ratio

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

●No issues in the `Issues` panel in Chrome Devtools

●Ensure CSP is effective against XSS attacks

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

●Page has valid source maps

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

SEO

Content Best Practices

Descriptive link text helps search engines understand your content. Learn how to make links more accessible.

Link destination	Link Text
spring.academy/	Learn more
spring.io/support	Learn more

Format your HTML in a way that enables crawlers to better understand your app’s content.

○Structured data is valid

●Page isn’t blocked from indexing

●Document has a `<title>` element

●Document has a meta description

●Page has successful HTTP status code

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`

Results for https://spring.io

Site Health

Top Priorities (5)

Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

Diagnostics

Accessibility

ARIA

Contrast

Names and labels

Best practices

Best Practices

General

SEO

Content Best Practices

Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

Diagnostics

Accessibility

ARIA

Contrast

Names and labels

Best Practices

General

SEO

Content Best Practices

Keyboard Shortcuts