What each tool computes

Accessibility Insights

Guided assessments combining fast pass, assessment and ad-hoc.

WCAG 2.1 AA 2.1

AccessMonitor

Portuguese government accessibility validator.

WCAG 2.1 AA 2.1

AChecker

Online checker for WCAG and BITV.

WCAG 2.0 AA 2.0

ANDI

Favelet revealing computed name/role/state.

WCAG 2.1 AA 2.1 · not stated

ARC Toolkit (TPGi)

Browser extension for WCAG audits with ARC engine.

WCAG 2.1 AA 2.1

Browser extension and API wrapping axe-core.

WCAG 2.1 AA 2.1

axe Linter (VS Code)

Lints JSX/HTML for accessibility in editor.

WCAG 2.1 AA 2.1

axe-core

Accessibility engine returning violations per WCAG rule.

WCAG 2.1 AA 2.1

eslint-plugin-jsx-a11y

ESLint rules for JSX accessibility.

WCAG 2.1 AA + ARIA 2.1

Injectable checker for WCAG 2.0/2.1 and Section 508.

WCAG 2.1 AA 2.1

IBM Equal Access Accessibility Checker

Browser extension and engine with IBM rule set.

WCAG 2.1 AA 2.1

Lighthouse Accessibility

Audits for accessibility and returns scored report via axe-core.

WCAG 2.1 AA 2.1

Validates HTML; parser check used as a11y pre-check.

HTML Living Standard

Pa11y

CLI and CI accessibility tester with selectable runners.

WCAG 2.1 AA 2.1

Browser extension highlighting WCAG failures inline.

WCAG 2.1 AA 2.1 · not stated

SortSite

Crawler checking accessibility, links and standards.

WCAG 2.1 AA 2.1

Tenon.io

API for accessibility testing with WCAG mapping.

WCAG 2.1 AA 2.1

tota11y

Visualisation overlay annotating headings, contrast, ARIA.

WCAG 2.1 general 2.1 · not stated

WAVE

In-page overlay showing errors, structure and ARIA.

WCAG 2.1 AA 2.1 · not stated

webhint

Linting for web best practices including a11y hints.

WCAG 2.1 AA 2.1 · not stated

Coblis — Color Blindness Simulator

Simulates images under eight CVD types via upload.

Brettel et al. CVD simulation

Desktop full-screen CVD filter.

CVD simulation filter

Colorblindly

Browser extension simulating CVD on any webpage.

CVD simulation via CSS filter

Pilestone Color Blind Simulator

Vendor simulator linked to corrective lens product.

CVD simulation · not stated

Sim Daltonism

macOS/iOS real-time CVD filter via camera.

CVD simulation

Acrolinx

Enterprise content governance and terminology checker.

Terminology governance

Alex

Catches insensitive and non-inclusive language.

Language sensitivity

proselint

Lints prose for jargon and clichés.

Prose linting

Vale

Lints prose against style guides and checks.

Prose linting (custom rules)

write-good

Lints English for weasel words and passive voice.

Weasel word detection

Accessible Colors

Tests combinations and proposes accessible alternatives.

WCAG 2.1 contrast ratio 2.1

Palette tool checking contrast and colour-blind safety.

WCAG 2.1 contrast ratio 2.1 · not stated

Calculates APCA lightness contrast (WCAG 3 draft).

APCA 0.1.9

Color.review

Checks colour pairs and suggests fixing hues for WCAG.

WCAG 2.1 contrast ratio 2.1 · not stated

Colorable (jxnblk)

Minimal WCAG contrast ratio rater.

WCAG 2.1 contrast ratio 2.1

Contrast Ratio (Lea Verou)

Minimal two-colour ratio calculator with WCAG grading.

WCAG 2.1 contrast ratio 2.1

Contrast-Finder (Tanaguru)

Finds nearest passing colour pair from a failing pair.

WCAG 2.1 contrast ratio 2.1

Palette-linked WCAG contrast checker.

WCAG 2.1 contrast ratio 2.1 · not stated

Matrix view of palette contrast across token sets.

WCAG 2.1 contrast ratio 2.1

Leonardo

Generates palettes with WCAG and APCA contrast calculations.

WCAG 2.1 contrast ratio 2.1 APCA 0.1.9

Snook Colour Contrast Check

Early WCAG contrast checker showing multiple ratios.

WCAG 2.0 contrast ratio 2.0

Stark Contrast Checker

Figma/Sketch plugin and browser contrast checker.

WCAG 2.1 contrast ratio 2.1

TPGi Colour Contrast Analyser

Desktop eyedropper that evaluates contrast including alpha compositing.

WCAG 2.1 contrast ratio 2.1

WebAIM Contrast Checker

Checks foreground/background colours for WCAG contrast compliance.

WCAG 2.1 contrast ratio 2.1

WhoCanUse

Shows WCAG grades across vision types and text sizes.

WCAG 2.1 contrast ratio 2.1

axe-core Rules Dataset

Structured list of axe rules with WCAG mapping.

WCAG SC mapping 2.1

Chrome UX Report (CrUX)

Field metrics dataset for UX including a11y-adjacent signals.

CrUX metrics

Color Contrast Dataset (Crowd)

Curated pairs of colours with human contrast judgements (placeholder corpus).

Human contrast judgements

HTTP Archive

Corpus of web crawl data including Lighthouse a11y.

Web crawl corpus

WebAIM Million

Annual dataset of top 1M home page a11y failures.

Axe failure corpus

Token set and tooling from Carbon Design System.

Carbon tokens

Diez

Cross-platform design token compiler.

Design Tokens

Primer Tokens

GitHub Primer design tokens and utilities.

Primer tokens

Specify

Automates token distribution from Figma to code.

Design Tokens

Build system transforming design tokens to platforms.

Design Tokens W3C draft

Supernova

Design system platform converting Figma to code.

Design Tokens

Theo

Design token transformer from Salesforce UX.

Design Tokens

Token Transformer

Converts Tokens Studio JSON to Style Dictionary format.

Design Tokens W3C

Tokens Studio for Figma

Figma plugin managing design tokens and syncing to Git.

Design Tokens W3C draft

Specification reference for design tokens format.

Design Tokens Specification draft

Tests browser autocomplete token support.

HTML autocomplete attribute

Form Ally Linter

Lints forms for label, fieldset and autocomplete issues.

WCAG 2.1 label checks 2.1

GOV.UK Design System Form Validation

Form validation patterns for UK government services.

GOV.UK Design System

HTML5 Input Types Tester

Shows rendering of HTML5 input types across browsers.

HTML Living Standard input types

Input Mask Accessibility Checker

Tests masked inputs for screen-reader announcement.

ARIA input mask

USWDS Form Components

Accessible form component reference and validator.

USWDS 3.0 3.0

Validates ARIA attributes in markup including forms.

WAI-ARIA 1.2 1.2

Reference patterns for accessible form widgets.

WAI-ARIA 1.2 1.2

Inspects accessibility tree alongside axe results.

Accessibility tree

BrowserStack Responsive

Cloud responsive testing across real devices.

Responsive cloud

Chrome DevTools

Browser inspector measuring layout, colour and a11y tree.

CSS/AX Tree inspection

Dimensions (Figma plugin)

Measures distances between Figma layers.

Figma measurement

Figma Measure

Generates spec measurements for Figma handoff.

Spec generation

Firefox Accessibility Inspector

Shows accessibility tree and contrast in Firefox.

Accessibility tree

Measure-it

Draws ruler to measure page elements.

Pixel measurement

PerfectPixel

Overlays semi-transparent image for pixel comparison.

Pixel overlay comparison

Outlines every element to reveal layout.

Layout outline

Overlay design image for pixel comparison in Chrome.

Pixel overlay

Dev browser with a11y and contrast panes.

Accessibility pane

Responsively App

Open-source dev browser for responsive design.

Multi-viewport

Sizzy

Synced multi-viewport browser for responsive inspection.

Multi-viewport

Inspect and edit any page's visual design.

Visual inspection

Resizes viewport to preset dimensions.

Viewport sizing

Datayze Readability Analyzer

Analyzes text for readability and suggests improvements.

Flesch-Kincaid

Dedicated Gunning Fog index calculator.

Gunning Fog

Hemingway App

Editor scoring readability by grade and sentence complexity.

Automated Readability Index

Readability Formulas

Collection of readability calculators and explanations.

Flesch Reading Ease

Readable

Scores text on Flesch-Kincaid, Gunning Fog, SMOG and others.

Flesch-Kincaid Gunning Fog SMOG

textstat

Python library computing readability metrics.

Flesch-Kincaid

WebFX Readability Tool

Free readability checker with Flesch-Kincaid score.

Flesch-Kincaid

JAWS

Commercial Windows screen reader.

IAccessible2/UIA

Narrator

Built-in Windows screen reader.

UIA

NVDA

Free Windows screen reader.

IAccessible2/UIA

TalkBack

Android screen reader.

AccessibilityNodeInfo

VoiceOver

Built-in macOS/iOS screen reader.

AX API

Tests which AT support which ARIA/HTML features.

AT support data

Authoring practices for ARIA patterns.

WAI-ARIA 1.2 1.2

Can I use

Browser support tables for web features including a11y.

Browser support

HTML Standard (WHATWG)

Living HTML specification.

HTML Living Standard

Inclusive Design Principles

Reference principles for inclusive design decisions.

Inclusive Design Principles

MDN Web Docs

Reference for HTML/CSS/JS and accessibility attributes.

HTML Living Standard

Validates HTML/CSS against specifications.

HTML Living Standard

Filterable reference for WCAG success criteria.

WCAG 2.1 2.1

Variable font specimen and axis tester.

OpenType variations

Trims whitespace from text bounding boxes via font metrics.

Font metrics trimming

Fluid Type Scale Calculator

Generates clamp-based fluid type scales.

CSS clamp fluid type

Font Gauntlet

Variable font proofing and QA web app.

OpenType QA

FontBakery

Font quality checker with 200+ checks.

Google Fonts spec

FontDrop

Drag-and-drop OpenType table inspector.

OpenType tables

Glyphhanger

Subsetting and glyph inspection via font file.

Glyph coverage

Modular Scale

Calculates typographic scales from ratio and base.

Modular scale

Variable font playground showing axis interpolation.

OpenType variations

Type Scale

Visual type scale preview with CSS output.

Type scale preview

Wakamai Fondue

Inspects variable font tables and features.

OpenType tables

WhatFontIs

Identifies fonts from uploaded images.

Font identification · not stated

Mapbox Wayfinding

Indoor/outdoor wayfinding map SDK.

Mapbox Streets

NaviLens

Accessible wayfinding codes for blind navigation.

NaviLens code

SignAgent

Wayfinding signage inventory and compliance platform.

ADA Signage · not stated

Transit Maps Maker

Tool for designing transit wayfinding maps.

Transit wayfinding · not stated

Cloud wayfinding CMS for signage networks.

Wayfinding signage CMS · not stated