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HTML Accessibility Checker — Validate Alt Text, Headings & More

Check your HTML for common accessibility issues: missing alt text, empty headings, missing form labels, and more.

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Accessibility Checker

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How It Works

1.Paste Your HTML

Paste the HTML you want to check. Works with any HTML — from Google Docs, your CMS, or hand-written.

2.Automated Scan

The tool scans for common accessibility issues: missing alt text, empty headings, missing form labels, and more.

3.Fix & Improve

Review the issues and fix them before publishing. Better accessibility means better reach.

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Why Accessibility Matters

Web accessibility ensures your content can be used by everyone, including people using screen readers or assistive technologies. Accessibility also correlates with better SEO rankings.

  • Screen readers need alt text to describe images
  • Empty headings confuse navigation tools
  • Proper structure improves SEO rankings
  • Inclusive design reaches more readers
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All Tools

SEO Slug Generator

AI-powered title to URL slug

CJK Auto-Spacing

Space CJK & Latin text

HTML Diff Viewer

Compare before & after HTML

Content Stats

Word count, reading time & more

OG Image Generator

Create social share images

Markdown Converter

HTML to Markdown and back

TOC Generator

Table of contents from headings

JSON-LD Builder

Schema markup for SEO

Or start with the main HTML cleanup tool

Open Publish Helper
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Frequently Asked Questions

What issues does this check?

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It checks for missing alt text on images, empty headings, broken heading hierarchy, missing form labels, and empty links.

Is my HTML sent to a server?

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No. Everything runs in your browser.

Is this tool free?

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Yes, completely free with no signup required.

Does this cover all WCAG criteria?

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This tool covers common accessibility issues. For full WCAG compliance, use a dedicated accessibility audit tool.

Changelog

v3.0.02026-05-03
  • NewHTML Diff Viewer — compare before and after HTML with a visual diff (green/red)
  • NewContent Stats Calculator — word count, reading time, heading, image, and link counts
  • NewHTML Accessibility Checker — detect missing alt text, empty headings, skipped levels, and more
  • NewOG Image Generator — create 1200×630 social share images from your blog post title
  • NewMarkdown ↔ HTML Converter — bidirectional conversion between Markdown and HTML
  • NewTable of Contents Generator — auto-generate nested TOC from heading tags in HTML or Markdown
  • NewJSON-LD Structured Data Builder — generate Article, BlogPosting, and FAQPage schema markup
  • NewAuto-clean on paste — optional toggle that auto-triggers cleanup when content is pasted
  • NewTable cleanup options — strip cell widths and remove empty table cells
  • NewAuto-save draft — content is saved to localStorage and restored on accidental refresh
  • NewAll new tools linked from the main page TOOLS & GUIDES section and related pages
v2.4.12026-04-27
  • NewParagraph option added to heading dropdown — convert headings back to normal text
  • FixH1–H6 heading prefixes now convert correctly even when pasted with leading line breaks
  • FixFixed page crash on load — cookie consent now renders reliably
  • ImprovedDependency updates for better performance and stability
v2.4.02026-04-17
  • NewClear button — quickly wipe all editor content and reset the HTML panel from the left panel header
  • FixEmpty <p></p> placeholder no longer appears in the HTML panel after clearing the editor
  • NewImage insert via URL — paste any image URL into the editor with a new toolbar popover
v2.3.22026-04-14
  • FixHeading conversion rewritten with DOM parsing — now works with any wrapper tag, split headings (H1 + body in same <p>), and safely preserves <li> inside lists
  • FixEmpty heading tags left behind by Google Docs are now automatically removed
v2.3.12026-03-25
  • FixHeading conversion now handles spaces before the colon (e.g. "H2 : Title")
  • FixRight-to-left content (Arabic, Hebrew) no longer inverts embedded English text in the editor
  • FixSpacer paragraphs (&nbsp;) are now preserved in the HTML output instead of being stripped
v2.3.02026-03-20
  • NewCJK auto-spacing — automatically insert spaces between Chinese/Japanese/Korean characters and English letters or numbers (powered by pangu.js)
  • NewStandalone CJK Auto-Spacing tool page with before/after examples, FAQ, and SEO-optimized bilingual content
  • NewChinese UI text auto-spacing — zh-TW interface text now has proper CJK–Latin spacing
  • FixMobile toolbar no longer floats and follows scrolling — stays pinned at the bottom of the editor
  • FixMobile toolbar buttons now scroll horizontally instead of overflowing
  • FixFind & Replace inputs no longer break out of the container on narrow screens
v2.2.12026-03-20
  • FixHeading conversion now uses the text prefix (e.g. H3:) to set the heading level, even when the content is already inside a different heading tag
v2.2.02026-03-18
  • NewAI-Powered Title to SEO Slug — Convert blog titles in any language to SEO-friendly English slugs in under 10 seconds
  • NewSlug generator toggle on the main page — generate slugs right after editing, above the fold
  • NewTable support — pasted tables from Google Docs now render correctly
  • NewRemove <br> after headings cleanup option (on by default)
  • NewPartial text selection copy in the HTML code view
  • NewSticky Clean HTML button at the bottom of the page
  • ImprovedHeading conversion now strips prefixes from existing heading tags and supports Chinese full-width colon (：)
  • ImprovedShared footer across all pages
v2.1.22026-03-17
  • FixBug fixes and improvements
v2.1.12026-03-16
  • FixBug fixes and improvements
v2.1.02026-03-16
  • NewFormatted/Raw toggle for the HTML code view
  • ImprovedCopying from the code panel now always gives clean, unformatted HTML
v2.0.02026-03-16
  • NewWelcome to Publish Helper — free online tools for content editors
  • ImprovedImproved search engine visibility
v1.1.02026-03-16
  • ImprovedClipboard copy — clean HTML output matches the code view
v1.0.02026-03-16
  • NewRich text editor with Google Docs paste support
  • NewHTML cleanup: strip styles, classes, empty tags, and Google Docs artifacts
  • NewHeading conversion from text prefixes to proper HTML tags
  • NewFind & replace with regex support and saveable presets
  • NewSyntax-highlighted HTML preview with one-click copy
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