Lighthouse Mobile
· 0 checks — Mobile Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.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.
Performance issues directly impact user engagement and conversion rates.
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
Performance issues directly impact user engagement and conversion rates.
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
Performance issues directly impact user engagement and conversion rates.
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
Performance issues directly impact user engagement and conversion rates.
Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads.
Performance issues directly impact user engagement and conversion rates.
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.
Performance issues directly impact user engagement and conversion rates.
Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.
Performance issues directly impact user engagement and conversion rates.
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
Performance issues directly impact user engagement and conversion rates.
| URL | Resource Size | Est Savings | |
|---|---|---|---|
Forever Stamps available from The Postal Store. div#usps-carousel > div.carousel-inner > div.carousel-item > img.d-block | www.usps.com/assets/images/welcome/carousel/apr26-stamps.png | 1.9 MiB | 1.9 MiB |
A person holding up a passport with luggage in the background. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/passport-luggage.jpg | 157.6 KiB | 144.2 KiB |
An Informed Delivery preview email on a smartphone. div.jumbotron > div.container-fluid > div.row > img | www.usps.com/assets/images/welcome/premium/id-app-m.jpg | 125.3 KiB | 119.0 KiB |
Person placing a label on a package. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/cns26-34.jpg | 111.2 KiB | 97.7 KiB |
Happy Birthday Forever Stamp. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/birthday.jpg | 104.6 KiB | 91.0 KiB |
An open PO Box with mail inside and a key in the lock. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/po-boxes-box.jpg | 76.3 KiB | 62.7 KiB |
USPS 250th anniversary. Delivering since 1775. Celebrate 250 years of USPS! Exp… div > div.container-fluid > a > img.d-lg-none | www.usps.com/assets/images/welcome/featured/250-landing-promo-m.jpg | 36.5 KiB | 18.2 KiB |
A postmark stamp that shows a cancellation date of January 13, 2026, in New Yor… div.inpage-alert > div.container-fluid > div.alert-p > img | www.usps.com/assets/images/campaigns/postmark/postmark-home.png | 16.9 KiB | 16.1 KiB |
body > div#global-footer--wrap > footer.global-footer > a.global-footer--logo-link body > div#global-footer--wrap > footer.global-footer > a.global-footer--logo-link | www.usps.com/global-elements/footer/images/footer-logo.png | 5.3 KiB | 4.3 KiB |
Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Duration |
|---|---|---|
| www.usps.com/global-elements/header/css/megamenu-v4.css | 8.0 KiB | |
| www.usps.com/assets/css/welcome/bootstrap.css | 26.6 KiB | 300 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.
Performance issues directly impact user engagement and conversion rates.
Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.
Performance issues directly impact user engagement and conversion rates.
| URL | Time Spent |
|---|---|
| usps.com/ | 1.1 s |
| www.usps.com/ | 0.0 ms |
These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS
Performance issues directly impact user engagement and conversion rates.
| Element | Layout shift score |
|---|---|
Click-N-Ship®
Buy Stamps
Informed Delivery®
PO Boxes™
Calculate a Price
Hold Ma… body > div.quicktools | 0.078 |
Postmarks: If you want to ensure that your mail receives a postmark on the day … body > div.inpage-alert | 0.053 |
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.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.usps.com/assets/css/welcome/bootstrap.css | 25.9 KiB | 24.4 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.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.googletagmanager.com/gtm.js?id=GTM-MVCC8H | 210.0 KiB | 66.3 KiB |
| www.googletagmanager.com/gtag/destination?id=DC-3976941&cx=c>m=4e64f0h1 | 129.2 KiB | 64.8 KiB |
| www.googletagmanager.com/gtag/js?id=AW-978081151 | 141.3 KiB | 63.4 KiB |
| www.googletagmanager.com/gtm.js?id=GTM-K2FRZL4>m=4e64f0h1 | 160.7 KiB | 58.2 KiB |
| www.usps.com/W0ci2XILbs/gI8D0ObD/fB/hibukfp0ELJDXD3kXY/cw0VPRww/OzB/yLgsuPigB | 168.7 KiB | 37.3 KiB |
| /signals/config/533374513433337?v=2.9.298&r=stable&domain... | 126.8 KiB | 36.7 KiB |
| connect.facebook.net/en_US/fbevents.js | 96.3 KiB | 33.4 KiB |
| www.usps.com/global-elements/footer/script/jquery-3.7.1.js | 29.7 KiB | 20.1 KiB |
| www.usps.com/assets/script/globals/jquery.min.js | 30.2 KiB | 20.1 KiB |
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.
Performance issues directly impact user engagement and conversion rates.
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
Performance issues directly impact user engagement and conversion rates.
| Category | Time Spent |
|---|---|
| Script Evaluation | 3.2 s |
| Other | 998 ms |
| Script Parsing & Compilation | 464 ms |
| Style & Layout | 358 ms |
| Garbage Collection | 92 ms |
| Rendering | 79 ms |
| Parse HTML & CSS | 71 ms |
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
Performance issues directly impact user engagement and conversion rates.
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
Performance issues directly impact user engagement and conversion rates.
| URL | |
|---|---|
Forever Stamps available from The Postal Store. div#usps-carousel > div.carousel-inner > div.carousel-item > img.d-block | www.usps.com/assets/images/welcome/carousel/apr26-stamps.png |
A person holding up a passport with luggage in the background. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/passport-luggage.jpg |
Person placing a label on a package. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/cns26-34.jpg |
Happy Birthday Forever Stamp. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/birthday.jpg |
An open PO Box with mail inside and a key in the lock. div.container-fluid > div.row > div.col-lg-7 > img | www.usps.com/assets/images/welcome/featured/po-boxes-box.jpg |
An Informed Delivery preview email on a smartphone. div.jumbotron > div.container-fluid > div.row > img | www.usps.com/assets/images/welcome/premium/id-app-m.jpg |
USPS 250th anniversary. Delivering since 1775. Celebrate 250 years of USPS! Exp… div > div.container-fluid > a > img.d-lg-none | www.usps.com/assets/images/welcome/featured/250-landing-promo-m.jpg |
USPS mobile logo div.nav-full > div.mobile-header > a.mobile-logo > img | www.usps.com/assets/images/home/logo_mobile.svg |
Tracking Icon ul > li > a > img | www.usps.com/assets/images/home/tracking.svg |
Search Icon div.nav-full > div.mobile-header > a.mobile-search > img | www.usps.com/assets/images/home/search.svg |
Informed Delivery Icon ul > li > a > img | www.usps.com/global-elements/header/images/utility-header/mailman.svg |
Post Office Locator Icon ul > li > a > img | www.usps.com/assets/images/home/location.svg |
Stamps Icon ul > li > a > img | www.usps.com/assets/images/home/stamps.svg |
ul > li > a > img ul > li > a > img | www.usps.com/global-elements/header/images/book-passport-appt.svg |
Schedule a Pickup Icon ul > li > a > img | www.usps.com/assets/images/home/schedule_pickup.svg |
Calculate a Price Icon ul > li > a > img | www.usps.com/assets/images/home/calculate_price.svg |
Zip Code™ Lookup Icon ul > li > a > img | www.usps.com/assets/images/home/find_zip.svg |
Holdmail Icon ul > li > a > img | www.usps.com/assets/images/home/holdmail.svg |
ul > li > a > img ul > li > a > img | www.usps.com/global-elements/header/images/transit-time.svg |
Change of Address Icon ul > li > a > img | www.usps.com/assets/images/home/change_address.svg |
Post Office Boxes Icon ul > li > a > img | www.usps.com/assets/images/home/po_box.svg |
Shipping Supplies Icon ul > li > a > img | www.usps.com/assets/images/home/free_boxes.svg |
ul > li > a > img ul > li > a > img | www.usps.com/assets/images/home/hs-code-search.svg |
Stamp Icon Link for Buy Stamps div.col-lg-2 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/stamps.svg |
Mail Carrier Icon Link for Informed Delivery div.col-lg-2 > div.article > a > img.mx-auto | www.usps.com/global-elements/header/images/utility-header/mailman.svg |
PO Box Icon Link for PO Boxes div.col-4 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/po_box.svg |
Calculator Icon Link for Calculate a Price div.col-4 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/calculate_price.svg |
Stop mail Icon Link for Hold Mail div.col-4 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/holdmail.svg |
ZIP Code Location Finder Icon Link for Look up a ZIP Code div.col-4 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/find_zip.svg |
House Icon Link for Change My Address div.col-4 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/change_address.svg |
Box and clock Icon Link for Schedule a Pickup div.col-4 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/schedule_pickup.svg |
Click-N-Ship Icon ul > li > a > img | www.usps.com/assets/images/home/featured_clicknship.svg |
Printer Icon Link for Click-N-Ship div.col-lg-2 > div.article > a > img.mx-auto | www.usps.com/assets/images/home/featured_clicknship.svg |
A postmark stamp that shows a cancellation date of January 13, 2026, in New Yor… div.inpage-alert > div.container-fluid > div.alert-p > img | www.usps.com/assets/images/campaigns/postmark/postmark-home.png |
hamburger menu Icon div.nav-full > div.mobile-header > a.mobile-hamburger > img | www.usps.com/assets/images/home/hamburger.svg |
Image of Threads social media icon. ul.global-footer--social > li > a > img | www.usps.com/global-elements/footer/images/threads_logo.png |
Image of X social media icon. ul.global-footer--social > li > a > img | www.usps.com/global-elements/footer/images/x_logo.png |
Image of Facebook social media icon. ul.global-footer--social > li > a > img | www.usps.com/global-elements/footer/images/facebook_logo.png |
Image of instagram social media icon. ul.global-footer--social > li > a > img | www.usps.com/global-elements/footer/images/instagram_logo.png |
Image of Pinterest social media icon. ul.global-footer--social > li > a > img | www.usps.com/global-elements/footer/images/pinterest_logo.png |
Image of Youtube social media icon. ul.global-footer--social > li > a > img | www.usps.com/global-elements/footer/images/youtube_logo.png |
body > img body > img | /pixel/capture?tags=8dd8cf55-3ae9-49dc-a25a-83dcfc60de58&... |
More information about the performance of your application. These numbers don't directly affect the Performance score.
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
Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes. Learn how to match ARIA attributes to their roles.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Slide 1 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li.active |
Slide 2 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li |
Slide 3 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li |
Slide 4 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li |
Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more about roles and required children elements.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Skip Quick Tools Links
Quick Tools
Track a Package
Informed Delivery
… div#g-navigation > div.nav-full > nav > ul.nav-list |
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.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Quick Tools nav > ul.nav-list > li.qt-nav > a.nav-first-element |
Send nav > ul.nav-list > li.menuheader > a#mail-ship-width |
Receive nav > ul.nav-list > li.menuheader > a.menuitem |
Shop nav > ul.nav-list > li.menuheader > a.menuitem |
Business nav > ul.nav-list > li.menuheader > a.menuitem |
International nav > ul.nav-list > li.menuheader > a.menuitem |
Help nav > ul.nav-list > li.menuheader > a.menuitem |
PO BOXES div.empty-search > ul > li > a |
PASSPORTS div.empty-search > ul > li > a |
FREE BOXES div.empty-search > ul > li > a |
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.
Names and labels
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
body > img body > img |
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.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
body > div#g-navigation > div.nav-full > a#endnav |
USPS 250th anniversary. Delivering since 1775. Celebrate 250 years of USPS! Exp… section.jumbotron > div > div.container-fluid > a |
body > div#global-footer--wrap > footer.global-footer > a.global-footer--logo-link body > div#global-footer--wrap > footer.global-footer > a.global-footer--logo-link |
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.
Tables and lists
Screen readers require list items (`<li>`) to be contained within a parent `<ul>`, `<ol>` or `<menu>` to be announced properly. Learn more about proper list structure.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Skip Quick Tools Links
Quick Tools
Track a Package
Informed Delivery
… div.nav-full > nav > ul.nav-list > li.qt-nav |
Skip Send Links
Send
Tools
Click-N-Ship
Stamps & Supplies
Look Up a ZIP Code™
C… div.nav-full > nav > ul.nav-list > li.menuheader |
Skip Receive Links
Receive
Tools
Tracking
Informed Delivery
Intercept a Package… div.nav-full > nav > ul.nav-list > li.menuheader |
Skip Shop Links
Shop
Shop
Stamps
Shipping Supplies
Cards & Envelopes
Personaliz… div.nav-full > nav > ul.nav-list > li.menuheader |
Skip Business Links
Business
Tools
Calculate a Business Price
Every Door Direct… div.nav-full > nav > ul.nav-list > li.menuheader |
Skip International Links
International
Tools
Calculate International Prices
Pri… div.nav-full > nav > ul.nav-list > li.menuheader |
Skip Help Links
Help
FAQs
Finding Missing Mail
Filing a Claim
Requesting a Refu… div.nav-full > nav > ul.nav-list > li.menuheader |
Slide 1 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li.active |
Slide 2 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li |
Slide 3 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li |
Slide 4 div#usps-carousel > div.carousel-inner > ol.carousel-indicators > li |
These are opportunities to improve the experience of reading tabular or list data using assistive technology, like a screen reader.
Best practices
Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more about the viewport meta tag.
Informational: a Permissions-Policy directive showing feature -> allowed origins.
Source: MDN Permissions-Policy
| Failing Elements |
|---|
head > meta head > meta |
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.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
USPS Service Updates li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Forms & Publications li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Government Services li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Rights & Permissions li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Postal Inspectors li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Inspector General li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Postal Explorer li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
National Postal Museum li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Resources for Developers li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Privacy Policy li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
Terms of Use li.global-footer--navigation-category > ol.global-footer--navigation-options > li > a |
One main landmark helps screen reader users navigate a web page. Learn more about landmarks.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
html html |
These items highlight common accessibility best practices.
Best Practices
General
Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.
Performance issues directly impact user engagement and conversion rates.
| Deprecation / Warning | Source |
|---|---|
| AttributionReporting | |
| SharedStorage | c.amazon-adsystem.com/aat/amzn.js line 1, col 7935 |
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
Performance issues directly impact user engagement and conversion rates.
| Source | Description |
|---|---|
Attestation check for Shared Storage on https://ara.paa-reporting-advertising.amazon failed. | |
Creating a worker from 'blob:https://www.usps.com/961ef534-3a48-492b-b8b3-799fe8f0a277' violates the following Content Security Policy directive: "script-src 'self' 'unsafe-inline' 'unsafe-eval' https:". Note that 'worker-src' was not explicitly set, so 'script-src' is used as a fallback. The action has been blocked. |
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.
Performance issues directly impact user engagement and conversion rates.
| Issue type |
|---|
| Content security policy |
Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more about source maps.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
| Link destination | Link Text |
|---|---|
| www.usps.com/manage/informed-delivery.htm | Learn More |
| www.usps.com/manage/informed-delivery.htm | Learn More |
| /s/article/Requirements-and-Standards-for-Sending-Domesti... | Learn more |
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
body > img body > img |
Format your HTML in a way that enables crawlers to better understand your app’s content.