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Accessibility

· 13 checks — Landmarks, headings, alt text, forms, and link quality rolled into one auditable list.
SCORE
53
GRADE
F
FIX
6
REVIEW
2
PASS
5
INFO
0
Checks
13
5 PASS 2 REVIEW 6 FIX
F
404 Error Page
Action
HTTP 403, custom page
FIX
HTTP 403, custom page
Warning::
Unexpected status code: HTTP 403
Expected HTTP 404 but received 403. This may confuse search engine crawlers.
Got: HTTP 403
Info::
Custom styled 404 page
404 Page Quality ✓ Custom 404 Page
Status Code HTTP 403 ✗Page Title Error 403 (Forbidden)!!1 ✓Custom Styling ✓Navigation ✗Homepage Link ✗Search Form ✗
F
Favicon & Branding
Action
2 icon(s) detected
FIX
2 icon(s) detected
Info::
favicon.ico present at site root
Info::
HTML icon links detected
Info::
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'>.
✓ favicon.ico Present
✓ PNG Icons Present
✗ Apple Touch Missing
✗ SVG Favicon Missing
✗ Manifest Icons Missing
✗ Multiple Sizes Missing
D
Web Manifest
Action
Not found
FIX
Not found
Info::
No web manifest found
No manifest at standard paths (/manifest.json, /site.webmanifest). A manifest is optional but enables PWA features like home screen installation and standalone display.

No web manifest found.

D
Dark Mode Support
Action
No dark mode signals
FIX
No dark mode signals
Info::
No dark mode signals detected
Consider adding CSS with @media (prefers-color-scheme: dark) and <meta name='color-scheme' content='light dark'>.
Info::
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.

D
Print Stylesheet
Action
No print styles
FIX
No print styles
Info::
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 ✗
F
Navigation UX
Action
No navigation patterns
FIX
No navigation patterns
Info::
No breadcrumbs, search, or skip link detected
These navigation aids help users orient themselves and find content efficiently, especially on large sites.
Breadcrumbs
Search
Skip Link
Labeled Navigation
Back to Top
Hamburger Menu
Sticky Navigation Cannot reliably detect (CSS-based)
0 of 6 testable patterns navigation patterns detected. Limited navigation support. Consider adding breadcrumbs, search, and skip link.
B
Landmark Structure
30 landmarks
REVIEW
30 landmarks
Info::
<main> landmark present
Warning::
No <nav> landmark found
Info::
No contentinfo (footer) landmark
Warning::
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
BANNER header MAIN ASIDE "left pane" CONTENTINFO (missing!)

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

A+
Heading Hierarchy
16 headings
PASS
16 headings
Info::
Single H1 present
  • H3 Table of contents
  • H1 Welcome to Colab!
  • H2 Google Colab is available in VS Code!
  • H2 🎁 Free Pro Plan for Gemini & Colab for US College Students 🎓
  • H2 Access popular AI models via Google-Colab-AI Without an API Key
  • H2 Explore the Gemini API
  • H2 What is Colab?
  • H2 Getting started
  • H2 Data science
  • H2 Machine learning
  • H2 More Resources
  • H3 Working with Notebooks in Colab
  • H3 Working with Data
  • H3 Machine Learning
  • H3 Using Accelerated Hardware
  • H3 Featured examples
A+
Alt Text Quality
1 of 2 images have issues
PASS
1 of 2 images have issues
Warning::
1 image(s) with filename as alt text
Info::
1 image(s) with good alt text
2 images 1 good alt text 1 generic
IssueCount
filename1 image(s)
A
Form Accessibility
1 of 2 controls have issues
PASS
1 of 2 controls have issues
Critical::
1 control(s) without accessible label
Form controls need a <label>, aria-label, or aria-labelledby for screen readers.
Got: <textarea name="g-recaptcha-response" id="g-recaptcha-response-100000">
Info::
1 control(s) properly labeled
2 controls
1 labeled
0 placeholder only
1 unlabeled
ControlTypeLabelMethod
#doc-nameinputNotebook namearia-label
#g-recaptcha-response-100000textarea(none)none

Form controls need a <label>, aria-label, or aria-labelledby for screen readers.

<textarea name="g-recaptcha-response" id="g-recaptcha-response-100000">

Why this matters

Form controls without labels — assistive tech announces 'edit text' with no context; users can't complete forms.

Source: WCAG 2.1 SC 3.3.2

A+
Color Contrast (Screenshot)
20 text elements analyzed, 0 fail WCAG AA
PASS

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

20 pass
Show all checked elements (20)
ElementRatioRequiredFGBGResult
h1 Welcome to Colab!19.01:13.0:1
#000000
#F0F4F9
Pass
h2 Google Colab is avai…19.01:13.0:1
#000000
#F0F4F9
Pass
h2 🎁 Free Pro Plan f…19.01:13.0:1
#000000
#F0F4F9
Pass
h2 Access popular AI mo…19.01:13.0:1
#000000
#F0F4F9
Pass
h2 Explore the Gemini A…19.01:13.0:1
#000000
#F0F4F9
Pass
h2 What is Colab?19.01:13.0:1
#000000
#F0F4F9
Pass
h2 Data science19.01:13.0:1
#000000
#F0F4F9
Pass
h2 Machine learning19.01:13.0:1
#000000
#F0F4F9
Pass
h2 More Resources19.01:13.0:1
#000000
#F0F4F9
Pass
h3 Table of contents19.01:13.0:1
#000000
#F0F4F9
Pass
h3 Working with Noteboo…19.01:13.0:1
#000000
#F0F4F9
Pass
h3 Working with Data19.01:13.0:1
#000000
#F0F4F9
Pass
h3 Machine Learning19.01:13.0:1
#000000
#F0F4F9
Pass
h3 Using Accelerated Ha…19.01:13.0:1
#000000
#F0F4F9
Pass
h3 Featured examples19.01:13.0:1
#000000
#F0F4F9
Pass
title Welcome To Colab - C…20.08:14.5:1
#000000
#F8FAFD
Pass
md-icon close20.08:14.5:1
#000000
#F8FAFD
Pass
md-icon close20.08:14.5:1
#000000
#F8FAFD
Pass
md-icon info20.08:14.5:1
#000000
#F8FAFD
Pass
div This notebook is ope…20.08:14.5:1
#000000
#F8FAFD
Pass

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.

A
Lighthouse Accessibility Audits
Score 92/100 — 2 failing, 26 passed
PASS
92

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.

Names and labels

When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. Learn how to make buttons more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
button#button button#button

Screen reader users rely on frame titles to describe the contents of frames. Learn more about frame titles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.output-iframe-sizer > div > div.outputview > iframe div.output-iframe-sizer > div > div.outputview > iframe

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.

○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
●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.
●ARIA attributes are used as specified for the element's role
●`[aria-hidden="true"]` elements do not contain focusable descendents
●Elements use only permitted ARIA attributes
●Background and foreground colors have a sufficient contrast ratio
●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.
●Heading elements appear in a sequentially-descending order
●Document has a main landmark.
●Deprecated ARIA roles were not used
●Elements with visible text labels have matching accessible names.
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○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
○`<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.
○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.
○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.
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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