Accessibility

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

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Checks

2 PASS 6 REVIEW 5 FIX

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-86t1s3

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.

Web Manifest

Action

Invalid JSON

FIX

Invalid JSON

Manifest contains invalid JSON

Manifest at https://clinicaltrials.gov/site.webmanifest contains invalid JSON. Browsers cannot parse it.

Got: https://clinicaltrials.gov/site.webmanifest

Manifest contains invalid JSON.

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

3 navigation landmark(s) detected

Hamburger menu detected (responsive design)

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 3 <nav> element(s)

Hamburger Menu

Sticky Navigation Cannot reliably detect (CSS-based)

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

Landmark Structure

10 landmarks

REVIEW

10 landmarks

<main> landmark present

3 <nav> landmark(s) found

All <nav> elements are properly labeled

No contentinfo (footer) landmark

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

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

Heading Hierarchy

3 headings

REVIEW

3 headings

No H1 heading found

Every page should have one H1 that describes the page content.

H4 Search for terms
H3 ClinicalTrials.gov is a place to learn about clinical studies from around the world.
H4 More Filters

Every page should have one H1 that describes the page content.

Why this matters

No H1 means screen-reader users can't identify the page's primary topic, and Google's content-extraction degrades.

Learn more ▾

The H1 is the document title for assistive tech and a strong signal to search engines about page topic. Pages without one force screen readers to fall back to the <title> attribute or page chrome. Add a single H1 that names the page's primary subject.

Source: WCAG 2.4.6 / Google Search Central

Alt Text Quality

1 of 10 images have issues

REVIEW

1 of 10 images have issues

1 image(s) missing alt attribute

Images without alt text are invisible to screen readers.

1 image-in-link without alt text

An image inside a link with no alt creates an empty link.

3 decorative image(s) correctly marked

6 image(s) with good alt text

10 images 6 good alt text 3 decorative 1 missing

Issue	Count
missing	1 image(s)

Images without alt text are invisible to screen readers.

Why this matters

Each image without alt text is a WCAG 1.1.1 failure — invisible to screen-reader users, lost from Google Image Search.

Learn more ▾

WCAG 2.1 Level A requires text alternatives for non-decorative images. Empty alt='' is fine for decorative; meaningful images need descriptive text. Common fixes: CMS audit + bulk add, build-time linter (alt-text-required ESLint rule), CI gate on Lighthouse a11y score.

Source: WCAG 2.1 SC 1.1.1 / WebAIM Million Report

An image inside a link with no alt creates an empty link.

Why this matters

Image-only links with no alt create empty links — screen-reader users hear 'link' with no destination context.

Learn more ▾

An <a><img></a> with no img alt is the worst-case for accessibility: AT announces the link but can't describe where it goes. Either add alt to the image OR add aria-label to the link.

Source: WCAG 2.1 SC 2.4.4

Link & Button Quality

Action

2 issue(s) across 86 links and 151 buttons

REVIEW

2 issue(s) across 86 links and 151 buttons

2 link(s) with no accessible text

Links without text are announced as raw URLs by screen readers.

Got: a#treatment-ind; a#local-menu-action-print

24 link(s) open in new tab without warning

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

Got: https://www.fda.gov/news-events/public-health-focus/expanded-access; https://ncbi.nlm.nih.gov; /about-site/about-ctg; /about-site/release-notes; /site-map; /study-basics/glossary; /about-site/disclaimer; /about-site/terms-conditions; https://ncbi.nlm.nih.gov; https://www.hhs.gov (+14 more)

60 link(s) with descriptive text

86 links

2 empty

0 generic text

24 new tab

0 empty buttons

Element	Text	Issue	Suggested Fix
https://www.fda.gov/news-events/public-h…	Expanded Access: Information f…	new tab	Add '(opens in new tab)' to text
	(empty)	empty	Add link text or aria-label
https://ncbi.nlm.nih.gov	NIH National Library of Medici…	new tab	Add '(opens in new tab)' to text
	(empty)	empty	Add link text or aria-label
/about-site/about-ctg	About ClinicalTrials.gov (open…	new tab	Add '(opens in new tab)' to text
/about-site/release-notes	Release Notes (opens in a new …	new tab	Add '(opens in new tab)' to text
/site-map	Site Map (opens in a new tab)	new tab	Add '(opens in new tab)' to text
/study-basics/glossary	Glossary (opens in a new tab)	new tab	Add '(opens in new tab)' to text
/about-site/disclaimer	Disclaimer (opens in a new tab…	new tab	Add '(opens in new tab)' to text
/about-site/terms-conditions	Terms and Conditions (opens in…	new tab	Add '(opens in new tab)' to text
https://ncbi.nlm.nih.gov	NIH National Library of Medici…	new tab	Add '(opens in new tab)' to text
https://www.hhs.gov	U.S. Department of Health and …	new tab	Add '(opens in new tab)' to text
https://www.nih.gov	National Institutes of Health …	new tab	Add '(opens in new tab)' to text
https://www.nlm.nih.gov	National Library of Medicine (…	new tab	Add '(opens in new tab)' to text
https://www.ncbi.nlm.nih.gov	National Center for Biotechnol…	new tab	Add '(opens in new tab)' to text
https://www.hhs.gov/about/index.html	About HHS (opens in a new tab)	new tab	Add '(opens in new tab)' to text
https://www.nih.gov/about-nih	About NIH (opens in a new tab)	new tab	Add '(opens in new tab)' to text
https://www.nlm.nih.gov/about	About NLM (opens in a new tab)	new tab	Add '(opens in new tab)' to text
https://www.ncbi.nlm.nih.gov/home/about	About NCBI (opens in a new tab…	new tab	Add '(opens in new tab)' to text
https://www.nlm.nih.gov/accessibility.ht…	Accessibility support (opens i…	new tab	Add '(opens in new tab)' to text
https://www.nih.gov/icd/od/foia/index.ht…	FOIA requests (opens in a new …	new tab	Add '(opens in new tab)' to text
https://eeo.nih.gov/no-fear-act	No FEAR Act Data (opens in a n…	new tab	Add '(opens in new tab)' to text
https://oig.hhs.gov	Office of the Inspector Genera…	new tab	Add '(opens in new tab)' to text
https://www.nlm.nih.gov/privacy.html	Privacy policy (opens in a new…	new tab	Add '(opens in new tab)' to text
https://www.hhs.gov/vulnerability-disclo…	HHS Vulnerability Disclosure (…	new tab	Add '(opens in new tab)' to text
https://www.usa.gov/	Visit USA.gov (opens in a new …	new tab	Add '(opens in new tab)' to text

211 links and buttons have descriptive text

Links without text are announced as raw URLs by screen readers.

a#treatment-ind; a#local-menu-action-print

Why this matters

Links with no accessible text (empty <a></a>, image-only no alt, icon-only no aria-label) are unidentifiable to screen readers.

Source: WCAG 2.1 SC 2.4.4

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

https://www.fda.gov/news-events/public-health-focus/expanded-access; https://ncbi.nlm.nih.gov; /about-site/about-ctg; /about-site/release-notes; /site-map; /study-basics/glossary; /about-site/disclaimer; /about-site/terms-conditions; https://ncbi.nlm.nih.gov; https://www.hhs.gov (+14 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

8 icon(s) detected

REVIEW

8 icon(s) detected

favicon.ico present at site root

HTML icon links detected

Apple touch icon present

SVG favicon detected — scales perfectly to any size

Multiple icon sizes detected

✓ favicon.ico Present

✓ PNG Icons Present

✓ Apple Touch Present

✓ SVG Favicon Present

✗ Manifest Icons Missing

✓ Multiple Sizes Present

Color Contrast (Screenshot)

Action

20 text elements analyzed, 3 fail WCAG AA

REVIEW

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

17 pass 3 fail WCAG AA

h4 Search for terms

2.75:1

#000000

#205493

needs 3.0:1 (large text)

16px · top of page (header area)

span Hide glossary

2.17:1

#000000

#1A4579

needs 4.5:1 (normal text)

16px · top of page (header area) · over background image/gradient

p Study record managers: refer to the

1.53:1

#000000

#112E51

needs 4.5:1 (normal text)

16px · above the fold

1 contrast failures on background images/gradients

These failures are invisible to CSS-based accessibility tools like Lighthouse. The text may be fine on a solid background, but fails when rendered over an image or gradient.

Show all checked elements (20)

Element	Ratio	Required	FG	BG	Result
h3 ClinicalTrials.gov i…	19.25:1	3.0:1	#000000	#EFF6FB	Pass
title Home \| ClinicalTrial…	18.43:1	4.5:1	#000000	#F0F0F0	Pass
span Show glossary	18.43:1	4.5:1	#000000	#F0F0F0	Pass
h4 Search for terms	2.75:1	3.0:1	#000000	#205493	Fail
span Hide glossary	2.17:1	4.5:1	#000000	#1A4579	Fail
p Study record manager…	1.53:1	4.5:1	#000000	#112E51	Fail
span Data Element Definit…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
p if submitting regist…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
button Accepts healthy volu…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
div A type of	16.82:1	4.5:1	#000000	#D9E8F6	Pass
span eligibility criteria	18.20:1	4.5:1	#000000	#E6F0F9	Pass
div that indicates wheth…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
span condition/disease	19.25:1	4.5:1	#000000	#EFF6FB	Pass
div being studied can pa…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
button Active comparator ar…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
span arm type	19.25:1	4.5:1	#000000	#EFF6FB	Pass
div in which a group of …	19.25:1	4.5:1	#000000	#EFF6FB	Pass
span intervention/treatme…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
div considered to be eff…	19.25:1	4.5:1	#000000	#EFF6FB	Pass
button Adverse event	19.25:1	4.5:1	#000000	#EFF6FB	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+

Form Accessibility

All 64 controls labeled

PASS

All 64 controls labeled

64 control(s) properly labeled

64 controls

64 labeled

0 placeholder only

0 unlabeled

Control	Type	Label	Method
#advcond	search	Condition/disease	aria-label
#advterm	search	Other terms	aria-label
#advintr	search	Intervention/treatment	aria-label
#location-input	search	In country, state, or city	aria-label
#adv-radio-status0	radio	All studies	for/id
#adv-radio-status1	radio	Recruiting and not yet recruiting studies	for/id
#adv-radio-sex0	radio	All	for/id
#adv-radio-sex1	radio	Female	for/id
#adv-radio-sex2	radio	Male	for/id
#age-groups-radio	radio	Select ranges	for/id
#adv-check-age-0	checkbox	Child (birth - 17)	for/id
#adv-check-age-1	checkbox	Adult (18 - 64)	for/id
#adv-check-age-2	checkbox	Older adult (65+)	for/id
#manual-age-range-radio	radio	Manually enter range	for/id
#from-age-input	input	From	for/id
#from-age-select	select	From Age	aria-label
#to-age-input	text	To	for/id
#to-age-select	select	To Age	aria-label
#adv-check0-healthy0	checkbox	Yes	for/id
#adv-check0-phase0	checkbox	Early Phase 1	for/id
#adv-check0-phase1	checkbox	Phase 1	for/id
#adv-check0-phase2	checkbox	Phase 2	for/id
#adv-check0-phase3	checkbox	Phase 3	for/id
#adv-check0-phase4	checkbox	Phase 4	for/id
#adv-check0-phase5	checkbox	Not applicable	for/id
#adv-check0-studyType0	checkbox	Interventional	for/id
#adv-check0-studyType1	checkbox	Observational	for/id
#adv-check0-studyType1-0	checkbox	Patient registries	for/id
#adv-check0-studyType2	checkbox	Expanded access	for/id
#adv-check0-studyType2-0	checkbox	Individual patients	for/id
#adv-check0-studyType2-1	checkbox	Intermediate-size population	for/id
#adv-check0-studyType2-2	checkbox	Treatment IND/Protocol	for/id
#adv-check0-results0	checkbox	With results	for/id
#adv-check0-results1	checkbox	Without results	for/id
#adv-check0-docs0	checkbox	Study protocols	for/id
#adv-check0-docs1	checkbox	Statistical analysis plans (SAPs)	for/id
#adv-check0-docs2	checkbox	Informed consent forms (ICFs)	for/id
#adv-check0-funderType0	checkbox	NIH	for/id
#adv-check0-funderType1	checkbox	Other U.S. federal agency	for/id
#adv-check0-funderType2	checkbox	Industry	for/id
#adv-check0-funderType3	checkbox	All others (individuals, universities, organizations)	for/id
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
input	text	Date Picker	aria-label
#advtitles	search	Title,Title Acronym	aria-label
#advoutc	search	Outcome measure	aria-label
#advspons	search	Sponsor,Collaborator	aria-label
#advlead	search	Sponsor (Lead)	aria-label
#advid	search	Study IDs	aria-label
#advlocn	search	Facility Name	aria-label
#adv-check0-violation0	checkbox	Yes	for/id
#adv-radio-ressub0	radio	No selection	for/id
#adv-radio-ressub1	radio	No results submitted	for/id
#adv-radio-ressub2	radio	Submitted, QC review not concluded	for/id
#adv-radio-child-ressub2-0	radio	Submission with QC comments available	for/id

A+

Lighthouse Accessibility Audits

Score 97/100 — 2 failing, 26 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
(all filters optional) `ctg-home-search-panel > div.home-search-panel > div.search-panel-header > span`

These are opportunities to improve the legibility of your content.

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
The U.S. government does not review or approve the safety and science of all st… `div.usa-alert__body > div.usa-accordion > div.usa-accordion__heading > button.usa-accordion__button`

○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

●`[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.

●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

○`[accesskey]` values are unique

○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

○`<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.

○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.