HTML Accessibility Checker – Alt, Language & Headings | NetworkUstad

Accessibility is not a finishing touch; it is how a page works for people who navigate by keyboard, screen reader, or other assistive technology. Four common faults account for a large share of real barriers: images without alt text, pages without a declared language, heading levels that skip, and links with no text at all. Each is easy to introduce and easy to fix, but hard to spot by eye across a whole page. This checker scans pasted HTML for exactly those four issues and reports each one with enough detail to fix it, without needing a browser extension or an audit service.

How to Use the HTML Accessibility Checker

1. Paste the HTML of a page or a section into the box.
2. Click Check Accessibility.
3. Read the issue list, grouped by check.
4. Fix the first issue in your source HTML.
5. Re-paste and re-check until the list is clean.
6. Repeat for templates, since one template fault repeats on every page.

Key Features

• Checks every image for a missing alt attribute.
• Checks the page language declaration.
• Detects skipped heading levels in document order.
• Finds links with no text and no image content.
• Reports counts per issue so fixes can be prioritised.
• Runs entirely in the browser; HTML is never uploaded.

What the Result Means

An empty issue list means these four checks pass, not that the page is fully accessible: colour contrast, keyboard order, and form labels need separate checks. Each reported issue is a concrete barrier: a missing alt leaves a screen reader user with a filename or silence, a missing language makes pronunciation guesswork, a skipped heading breaks the document outline that readers navigate by, and an empty link is invisible in a links list. Fixing all four is a solid baseline, and the fixes are usually one attribute or one line of text each.

Worked Example

A blog post contains a chart image without alt text, a heading structure that jumps from h1 to h3, and a social icon link with no text. Pasting the post HTML here reports all three issues with counts, so the editor adds a one-sentence alt description, demotes the h3 to h2, and labels the icon link. Re-checking returns a clean list for these checks, and the post is meaningfully more usable for screen reader visitors, all from three small edits.

Best Practices and Tips

• Write alt text that conveys the image purpose, not just its appearance.
• Set the language on the html element for every page, even single-language sites.
• Use headings in order: one h1, then h2 sections, then h3 subsections.
• Give every link descriptive text; avoid link text such as click here.
• Run this check on templates and components, where one fix helps every page.

Common Mistakes to Avoid

• Treating alt text as optional for decorative images; use an empty alt for those, not a missing one.
• Skipping from h1 to h3 because the h3 styling looks better.
• Leaving icon-only links without text or an accessible label.
• Assuming a clean result here means full accessibility compliance.

Frequently Asked Questions

What is alt text for?

It describes an image for people who cannot see it, including screen reader users and anyone with images disabled.

Why does page language matter?

Screen readers use it to choose pronunciation, and browsers use it for translation and spell-checking.

What is a skipped heading level?

Going from h1 straight to h3, or h2 to h4, which breaks the outline that assistive tools use to navigate.

Are empty links always wrong?

A link with no text and no image is unusable for assistive tools; icon links need text or an accessible label.

Related Tools

• HTML List Generator – Build HTML list markup
• HTML Form Generator – Build HTML form markup