Accessibility guide

Section 508 Accessibility Checker: Test Web Content Against the Revised 508 Standards

AccessibilityScore.in scans a public web page for WCAG failures, which is where most Section 508 web defects show up. This guide explains who Section 508 covers, how the Revised 508 Standards relate to WCAG, and how to use an automated check alongside manual 508 testing.

Last reviewed 16 Oct 2026 by the HalfAccessible accessibility team

Short Answer

A Section 508 accessibility checker tests web content against the Revised 508 Standards, which apply WCAG 2.0 Level A and AA to federal agency websites, documents and software. Automated checks find many technical failures quickly, but full Section 508 conformance also requires manual testing with keyboards and assistive technology.

Key facts

Law: Section 508 of the Rehabilitation Act of 1973, as amended in 1998 (29 U.S.C. 794d)
Who must comply: Federal agencies that develop, procure, maintain or use information and communication technology (ICT)
Current standards: Revised 508 Standards from the US Access Board, published 18 January 2017, in effect since 18 January 2018
Web and document standard: WCAG 2.0 Level A and AA, incorporated by reference
Applies to: Websites, electronic documents such as PDF and Office files, software, mobile apps and hardware
Vendor evidence: An Accessibility Conformance Report (ACR), usually written with the VPAT 508 edition

Who does Section 508 apply to?

Section 508 applies to federal agencies. They must make the ICT they develop, buy, maintain or use accessible to employees and members of the public with disabilities, unless an exception applies.

The law does not directly regulate private companies, but it reaches them through procurement: vendors selling software, websites or digital services to federal agencies are asked to show how their products meet the Revised 508 Standards, usually with an Accessibility Conformance Report. Many state governments, universities and contractors also adopt Section 508 in their own policies.

How does Section 508 relate to WCAG?

The Revised 508 Standards incorporate WCAG 2.0 Level A and AA by reference and apply those success criteria to both web and non-web electronic content. In practice, a web page that meets WCAG 2.0 AA meets the 508 requirements for web content.

For non-web documents and software, four WCAG criteria that only make sense on websites do not apply: 2.4.1 Bypass Blocks, 2.4.5 Multiple Ways, 3.2.3 Consistent Navigation and 3.2.4 Consistent Identification. The standards also add functional performance criteria and requirements for hardware, software and support documentation that WCAG does not cover.

Because WCAG 2.1 and 2.2 include every WCAG 2.0 criterion except the obsolete 4.1.1 Parsing, building to WCAG 2.2 AA covers the 508 web requirements and the newer standards buyers increasingly ask for.

What can a Section 508 checker test automatically?

A checker can test the WCAG 2.0 AA criteria that are decidable from code. AccessibilityScore.in runs axe-core and its own rules on the rendered page and reports failures such as:

Missing text alternatives for images and icon buttons (1.1.1)
Form fields without labels or instructions (1.3.1, 3.3.2)
Text below the 4.5:1 contrast ratio (1.4.3)
Controls with no accessible name, role or state (4.1.2)
Missing page title and page language (2.4.2, 3.1.1)
Missing visible focus indicators (2.4.7)

What does Section 508 testing need beyond a scan?

Federal testers use manual methods, such as the Trusted Tester process from the Department of Homeland Security, for everything a tool cannot judge. Plan to test:

Keyboard access to every function, with a visible and logical focus order
Screen reader output for headings, forms, tables, errors and dynamic updates
Captions and audio description for multimedia
Accessibility of PDFs and Office documents you publish, not just HTML pages
Authenticated areas and multi-step tasks, which a public page scan never reaches

Section 508 vs WCAG at a glance

Aspect	Section 508 (Revised Standards)	WCAG
What it is	US federal law and procurement standard	W3C technical guidelines
Who must follow it	Federal agencies, and vendors through contracts	Whoever a law, policy or contract requires
WCAG version	WCAG 2.0 Level A and AA	2.0, 2.1 or 2.2, at Level A, AA or AAA
Scope	Web, documents, software, hardware, support docs	Web content; applied to other formats by guidance
Evidence	Accessibility Conformance Report (ACR)	Conformance claim or audit report

Common Questions

Does Section 508 apply to private companies?

Not directly. It applies to federal agencies. Private companies meet it when they sell ICT to the federal government, because agencies must buy accessible products and ask vendors for evidence.

Which WCAG version does Section 508 require?

WCAG 2.0 Level A and AA. Meeting WCAG 2.1 or 2.2 AA also satisfies it, because the newer versions keep the 2.0 criteria apart from the obsolete 4.1.1 Parsing.

When did the Revised 508 Standards take effect?

The US Access Board published them on 18 January 2017, and they took effect on 18 January 2018.

Is a 508 checker enough to prove compliance?

No. It finds technical failures quickly, but conformance needs manual testing of keyboard use, screen reader output, documents and full tasks.

Do PDFs have to meet Section 508?

Yes. Electronic documents such as PDF and Office files must meet WCAG 2.0 Level A and AA, with four web-only criteria excepted.

What document do vendors provide for Section 508?

An Accessibility Conformance Report (ACR), usually created with the Section 508 edition of ITI's Voluntary Product Accessibility Template (VPAT).

Is this Section 508 checker free?

Yes, for a single public HTTPS page. Whole-site scans use page scan credits, at $10 for 1,000 pages.

Sources

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