Accessibility

· 13 checks — Landmarks, headings, alt text, forms, and link quality rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Checks

3 PASS 5 REVIEW 5 FIX

Landmark Structure

Action

4 landmarks

FIX

4 landmarks

No <main> landmark found

Screen reader users cannot quickly navigate to the primary content. Wrap your main content in <main>.

2 <nav> landmark(s) found

2 of 2 <nav> elements are unlabeled

Multiple navigations need aria-label to distinguish them for screen readers.

Skip navigation link is missing (WCAG 2.4.1)

Add a skip link as the first focusable element so keyboard users can bypass repeated navigation.

Page Structure — as a screen reader sees it

Screen reader users cannot quickly navigate to the primary content. Wrap your main content in <main>.

Why this matters

Without a <main> landmark, screen-reader users can't skip past the navigation to the page content — every page starts with re-reading the menu.

Learn more ▾

The <main> element marks the page's primary content area. Assistive tech offers a 'jump to main' shortcut — but only if <main> exists. Without it, every page navigation forces re-reading the header. Wrap your primary content in a single <main>.

Source: WAI-ARIA / WCAG 2.4.1

Multiple navigations need aria-label to distinguish them for screen readers.

Why this matters

Some <nav> elements lack aria-label — screen-reader users hear 'navigation' multiple times with no way to distinguish them.

Learn more ▾

When a page has multiple <nav> regions (primary, footer, breadcrumb), each needs aria-label or aria-labelledby. AT users navigate by landmark; identical 'navigation' announcements force them to enter each one to discover purpose.

Source: WAI-ARIA Authoring Practices

Add a skip link as the first focusable element so keyboard users can bypass repeated navigation.

Why this matters

Without a skip-nav link, keyboard users tab through every nav item before reaching content — every page, every visit.

Learn more ▾

WCAG 2.4.1 (Bypass Blocks) requires a mechanism to skip past repeated content. The standard implementation is a 'Skip to main content' link that's the first focusable element, visually hidden until focused. Three lines of HTML + four of CSS.

Source: WCAG 2.1 SC 2.4.1

404 Error Page

Action

Soft 404 detected

FIX

Soft 404 detected

Soft 404: server returns HTTP 200 for non-existent pages

The server returns HTTP 200 for a path that does not exist. Search engines will index these pages, diluting your real content. Configure your server to return a proper 404 status code for missing pages.

Got: Status: 200 for /beavercheck-404-test-ph4zr9

404 Page Quality ✗ Soft 404 (HTTP 200)

Status Code: HTTP 200

The server returned HTTP 200 for a non-existent path. Search engines will index this page as real content. Configure your server to return HTTP 404 for missing pages.

Dark Mode Support

Action

No dark mode signals

FIX

No dark mode signals

No dark mode signals detected

Consider adding CSS with @media (prefers-color-scheme: dark) and <meta name='color-scheme' content='light dark'>.

Detection limited to meta tags and inline styles

External CSS files may contain prefers-color-scheme rules not visible to this scan.

Dark ModeNo Dark Mode Detected

color-scheme meta Not set ✗Dark theme-color Not set ✗CSS indicators Not detected ✗

Detection limited to meta tags and inline styles.

Print Stylesheet

Action

No print styles

FIX

No print styles

No print-specific styles detected

When users print this page, they get the screen layout including navigation and non-essential elements. Add @media print rules to hide navigation and optimize layout for paper.

Print Stylesheet No Print Styles

Print stylesheet Not found ✗Inline @media print Not detected ✗

Navigation UX

Action

No navigation patterns

FIX

No navigation patterns

2 navigation landmark(s) detected

No breadcrumbs, search, or skip link detected

These navigation aids help users orient themselves and find content efficiently, especially on large sites.

Breadcrumbs

Skip Link

Labeled Navigation 2 <nav> element(s)

Hamburger Menu

Sticky Navigation Cannot reliably detect (CSS-based)

1 of 6 testable patterns navigation patterns detected. Limited navigation support. Consider adding breadcrumbs, search, and skip link.

Heading Hierarchy

22 headings, 2 skip(s)

REVIEW

22 headings, 2 skip(s)

Single H1 present

Heading level skipped: H2 → H4 (missing H3)

Skipping heading levels breaks the document outline. Screen readers may interpret missing levels as structural errors.

Heading level skipped: H2 → H4 (missing H3)

Skipping heading levels breaks the document outline. Screen readers may interpret missing levels as structural errors.

H3 CodeSandbox is now part of Together AI! We have joined forces to launch CodeSandbox SDK and bring code interpretation to generative AI.
H1 Sandboxesbuilt for scale
H2 Programmatically spin up isolated sandboxes for instant code execution in your AI agents and code playgrounds.
H2 Secure code generation at scale
H3 Powerful APIs
H3 Secure & isolated
H3 Ready for scale
H3 Continuous context
H3 Quick start & auto resume
H3 Customizable hibernation
H2 Built for AI agents and more
H4 AI agents skipped
H4 Development environments at scale
H4 Secure code interpretation & evals
H4 CI/CD
H2 Template universe
H2 Start with your favorite stack.
H4 0 million+ skipped
H4 0+
H4 0+
H4 0.0 billion+
H2 Join the future of building

Skipping heading levels breaks the document outline. Screen readers may interpret missing levels as structural errors.

Why this matters

Skipping heading levels breaks the document outline — screen-reader users lose track of section nesting.

Learn more ▾

Screen reader users navigate by jumping between headings (H1 → H2 → H3). Skipping (H1 → H3) breaks the sense of hierarchy. Use sequential levels even if you don't like the default styling — restyle with CSS instead. WCAG 1.3.1 (Info and Relationships) treats this as an A failure.

Source: WCAG 2.1 SC 1.3.1 / W3C WAI

Skipping heading levels breaks the document outline. Screen readers may interpret missing levels as structural errors.

Why this matters

Skipping heading levels breaks the document outline — screen-reader users lose track of section nesting.

Learn more ▾

Source: WCAG 2.1 SC 1.3.1 / W3C WAI

Link & Button Quality

1 issue(s) across 59 links and 0 buttons

REVIEW

1 issue(s) across 59 links and 0 buttons

1 link(s) with generic text

Generic link text like 'click here' doesn't describe the destination.

Got: /blog/joining-together-ai-introducing-codesandbox-sdk ("Learn more")

16 link(s) open in new tab without warning

Add '(opens in new tab)' to link text or aria-label.

Got: /signin?utm_source=landingpage; /new?utm_source=landingpage; https://www.codesandbox.community/; /docs; https://together.ai; https://codesandbox.io/sdk; /new?utm_source=landingpage; https://codesandbox.io/docs/sdk#quickstart; /new?utm_source=startcodingcta; https://sandpack.codesandbox.io/ (+6 more)

42 link(s) with descriptive text

59 links

0 empty

1 generic text

16 new tab

0 empty buttons

Element	Text	Issue	Suggested Fix
/signin?utm_source=landingpage	Sign In	new tab	Add '(opens in new tab)' to text
/new?utm_source=landingpage	Try for free	new tab	Add '(opens in new tab)' to text
https://www.codesandbox.community/	diversity_4CommunityEngage wit…	new tab	Add '(opens in new tab)' to text
/docs	Docs	new tab	Add '(opens in new tab)' to text
https://together.ai	Together AI!	new tab	Add '(opens in new tab)' to text
https://codesandbox.io/sdk	CodeSandbox SDK	new tab	Add '(opens in new tab)' to text
/blog/joining-together-ai-introducing-co…	Learn more	generic text	Replace with descriptive text
Before: Learn more Suggested: Joining Together Ai Introducing Codesandbox Sdk
/new?utm_source=landingpage	Start for free	new tab	Add '(opens in new tab)' to text
https://codesandbox.io/docs/sdk#quicksta…	Try CodeSandbox SDK	new tab	Add '(opens in new tab)' to text
/new?utm_source=startcodingcta	Start for free	new tab	Add '(opens in new tab)' to text
https://sandpack.codesandbox.io/	Sandpack	new tab	Add '(opens in new tab)' to text
https://status.codesandbox.io/	Status	new tab	Add '(opens in new tab)' to text
/docs/	Documentation	new tab	Add '(opens in new tab)' to text
https://github.com/codesandbox/codesandb…	Github	new tab	Add '(opens in new tab)' to text
https://twitter.com/codesandbox	Twitter	new tab	Add '(opens in new tab)' to text
https://www.codesandbox.community/	Community	new tab	Add '(opens in new tab)' to text
https://www.youtube.com/c/CodeSandbox	YouTube	new tab	Add '(opens in new tab)' to text

42 links and buttons have descriptive text

Generic link text like 'click here' doesn't describe the destination.

/blog/joining-together-ai-introducing-codesandbox-sdk ("Learn more")

Why this matters

Generic anchor text ('click here', 'read more', 'learn more') tells screen readers and search engines nothing about the destination.

Learn more ▾

Out-of-context lists of links read by AT (one navigation pattern) become useless when every link says 'click here'. Use the destination's title or topic as anchor text. Doubles as SEO win — Google passes anchor-text relevance to the destination.

Source: WCAG 2.4.4 / Google Search Central

Add '(opens in new tab)' to link text or aria-label.

/signin?utm_source=landingpage; /new?utm_source=landingpage; https://www.codesandbox.community/; /docs; https://together.ai; https://codesandbox.io/sdk; /new?utm_source=landingpage; https://codesandbox.io/docs/sdk#quickstart; /new?utm_source=startcodingcta; https://sandpack.codesandbox.io/ (+6 more)

Why this matters

Links with target="_blank" without rel="noopener" leak the originating page's window context — security and UX issue.

Learn more ▾

Without rel="noopener", the new tab can navigate the original tab via window.opener (tab-nabbing attack). Modern browsers default to noopener for target=_blank but only since recent versions. Always set rel="noopener noreferrer" explicitly.

Source: MDN target / OWASP

Favicon & Branding

Action

11 icon(s) detected

REVIEW

11 icon(s) detected

favicon.ico present at site root

HTML icon links detected

No apple-touch-icon detected

iOS devices use this when users add your site to their home screen. Add <link rel='apple-touch-icon' sizes='180x180' href='/apple-touch-icon.png'>.

Multiple icon sizes detected

✓ favicon.ico Present

✓ PNG Icons Present

✗ Apple Touch Missing

✗ SVG Favicon Missing

✓ Manifest Icons Present

✓ Multiple Sizes Present

Web Manifest

Valid manifest

REVIEW

Valid manifest

Name present: CodeSandbox

No 192x192 icon

A 192px icon is required for PWA installation.

512x512 icon present

Display mode: standalone

PWA Install Criteria Not Installable

Name CodeSandbox ✓192×192 icon ✗512×512 icon ✓Start URL /dashboard?utm_source=homescreen ✓Display Mode standalone ✓

Name CodeSandbox Display Mode standalone Theme Color #1C2022 Background Color #1C2022 Icons 9 icon(s)

Color Contrast (Screenshot)

Action

20 text elements analyzed, 20 fail WCAG AA

REVIEW

Analyzes text contrast against the actual rendered page, including background images, gradients, and overlays that CSS-based tools cannot detect.

0 pass 20 fail WCAG AA

h2 Programmatically spin up isolated sandbo…

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

24px · bottom of viewport

h2 Secure code generation at scale

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

24px · bottom of viewport

h2 Built for AI agents and more

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

24px · bottom of viewport

h2 Template universe

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

24px · bottom of viewport

h2 Start with your favorite stack.

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

24px · bottom of viewport

h2 Join the future of building

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

24px · bottom of viewport

h3 CodeSandbox is now part of

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 We have joined forces to launch

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 and bring code interpretation to generat…

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 Powerful APIs

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 Secure & isolated

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 Ready for scale

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 Continuous context

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 Quick start & auto resume

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

h3 Customizable hibernation

1.09:1

#000000

#0E0E0E

needs 3.0:1 (large text)

19px · bottom of viewport

title CodeSandbox: Instant Cloud Development E…

1.25:1

#000000

#1D1D1D

needs 4.5:1 (normal text)

16px · top of page (header area)

a Sign In

1.25:1

#000000

#1D1D1D

needs 4.5:1 (normal text)

16px · top of page (header area)

a Try for free

1.16:1

#000000

#161616

needs 4.5:1 (normal text)

16px · top of page (header area)

a Features

1.16:1

#000000

#161616

needs 4.5:1 (normal text)

16px · top of page (header area)

a Use Cases

1.16:1

#000000

#161616

needs 4.5:1 (normal text)

16px · above the fold

Show all checked elements (20)

Element	Ratio	Required	FG	BG	Result
h2 Programmatically spi…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h2 Secure code generati…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h2 Built for AI agents …	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h2 Template universe	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h2 Start with your favo…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h2 Join the future of b…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 CodeSandbox is now p…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 We have joined force…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 and bring code inter…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 Powerful APIs	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 Secure & isolated	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 Ready for scale	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 Continuous context	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 Quick start & auto r…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
h3 Customizable hiberna…	1.09:1	3.0:1	#000000	#0E0E0E	Fail
title CodeSandbox: Instant…	1.25:1	4.5:1	#000000	#1D1D1D	Fail
a Sign In	1.25:1	4.5:1	#000000	#1D1D1D	Fail
a Try for free	1.16:1	4.5:1	#000000	#161616	Fail
a Features	1.16:1	4.5:1	#000000	#161616	Fail
a Use Cases	1.16:1	4.5:1	#000000	#161616	Fail

Methodology: The top 20 text elements by font size were checked. Background color was sampled from the desktop screenshot using a 5-point pattern. WCAG 2.1 AA requires 4.5:1 for normal text and 3:1 for large text.

Alt Text Quality

40 of 64 images have issues

PASS

40 of 64 images have issues

40 image(s) with generic alt text

24 image(s) with good alt text

64 images 24 good alt text 40 generic

Issue	Count
generic	40 image(s)

A+

Form Accessibility

No form controls

PASS

No form controls

No form controls on this page

No form controls found.

A+

Lighthouse Accessibility Audits

Score 95/100 — 2 failing, 25 passed

PASS

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.

Contrast

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Software Engineer, React Team `div.c-guBENg > div.c-guBENg > div.c-guBENg > span.c-gTFglp`
Designer Developer, Stripe `div.c-guBENg > div.c-guBENg > div.c-guBENg > span.c-gTFglp`
Senior Software Engineer `div.c-guBENg > div.c-guBENg > div.c-guBENg > span.c-gTFglp`
Co-creator of Astro `div.c-guBENg > div.c-guBENg > div.c-guBENg > span.c-gTFglp`

These are opportunities to improve the legibility of your content.

Navigation

Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
AI agents `div.c-eeXALW > div.c-guBENg > div.c-guBENg > h4.c-bfvcVA`
0 million+ `div.c-eeXALW > div.c-guBENg > div > h4.c-exFArQ`

These are opportunities to improve keyboard navigation in your application.

○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.

●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.

●Links have a discernible name

●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.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

●Elements with visible text labels have matching accessible names.

○`[accesskey]` values are unique

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

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

○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.

○`[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

○Form elements have associated labels

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

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

○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.

○Uses ARIA roles only on compatible elements

○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.

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.