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Image ALT Tag Checker

Find images missing alt text, empty alt attributes, and get a full audit of image accessibility and SEO.

Image ALT Tag CheckerGratisOn-Page SEOChecks a live URL

Enter a public URL. We fetch the live page and analyse what search engines and AI crawlers see.

Key features of the image alt tag checker

  • Lists all images found on the page with their current alt text
  • Flags images with missing or empty alt attributes
  • Identifies decorative images correctly marked with empty alt (alt='')
  • Shows image src URL for easy identification
  • Counts total images, missing alt count, and compliance rate

How to use the image alt tag checker

  1. Enter the page URL

    Paste the full URL of the webpage you want to audit into the input field.

  2. Run the audit

    Click 'Check Alt Tags'. The tool fetches the page and extracts all img elements.

  3. Review the image list

    See all images with their current alt text status — missing, empty, or present.

  4. Identify missing alt text

    Red items indicate images with no alt attribute. Yellow indicates empty alt text.

  5. Add optimised alt text

    Update images in your CMS with descriptive, keyword-relevant alt text and re-run to confirm.

What is an image alt tag checker?

The Image ALT Tag Checker scans any webpage and audits every image for alt text presence, emptiness, and quality. It identifies images with missing alt attributes, empty alt text, and over-long descriptions — giving you a complete picture of your page's image SEO and accessibility compliance.

Alt text serves two critical purposes: it tells search engines what an image depicts (contributing to image search rankings and page relevance), and it provides a text alternative for visually impaired users relying on screen readers. Both SEO and WCAG 2.1 accessibility guidelines require meaningful alt text on all informational images.

Why use an image alt tag checker?

Missing alt text is one of the most common on-page SEO errors. It leaves valuable image search ranking opportunities on the table and fails users with visual impairments. A quick alt text audit can uncover dozens of missed optimisation opportunities on a single page.

Image alt tag checker: frequently asked questions

Something else? Ask the team

What is image alt text?

Alt text (alternative text) is an HTML attribute added to img tags that describes the image content. It's read by screen readers for accessibility and by search engines to understand image context.

How does alt text affect SEO?

Alt text helps search engines index your images for Google Image Search, contributes to the overall topical relevance of your page, and can include target keywords naturally.

Should every image have alt text?

Informational images should always have descriptive alt text. Decorative images (backgrounds, spacers) should have an empty alt attribute (alt='') to indicate they can be skipped by screen readers.

How long should alt text be?

Alt text should be concise and descriptive — typically 5–15 words or 50–125 characters. Avoid keyword stuffing; describe what the image actually shows.

Can missing alt text cause accessibility violations?

Yes. Missing alt text on informational images is a WCAG 2.1 Level A violation, which can create legal liability for website owners in many jurisdictions.

Each one opens on its own page and works straight away, with no sign-up.

Ontdek meer gratis tools:Schema GeneratorMetatag GeneratorLLMs.txt GeneratorBrowse all free tools

Meer AI-vermeldingen winnen?

Image ALT Tag Checker is one piece of the puzzle. See how ChatGPT, Gemini, Perplexity, and Google AI Overviews actually view your brand, and get a prioritised list of fixes, with a free AEO & GEO audit from AI Rank Lab.

One check is a start. The audit checks the whole site.

Voer een gratis AEO- en GEO-audit uit or Bekijk prijzen.

  • Scores SEO, answer-engine (AEO) and generative-engine (GEO) readiness
  • Lists the fixes, page by page
  • Then track whether ChatGPT, Gemini, Perplexity and Google AI Overviews cite you
fieldnote.app4,571 credits

Site audit

fieldnote.app · SEO, AEO and GEO

Illustrative data
SEO
82
+6
AEO
64
+11
GEO
58
+9
Pages
48
Fixesby impact
  • /pricing · Missing H1High
  • /blog/guide · No FAQ schemaMedium
  • /llms.txt · Not foundMedium
  • /about · Meta description too longLow

See where your whole site stands

Paste your site. The free audit scores it for SEO, answer engines and generative engines, with the fixes.

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