Web Image Accessibility & Alt‑Text Compliance
Last updated: May 2025
1 | Why alt text matters
- Accessibility: screen‑reader users rely on alt text to understand what an image conveys.
- Compliance: most global regulations reference WCAG 2.1 AA — and its Success Criterion 1.1.1 requires a text alternative for every non‑decorative image.
- SEO & UX: search engines index alt text, improving image‑search rankings and providing visible fallback when images fail to load.
2 | Global baseline standards
| Standard | Scope | Key point for images |
|---|---|---|
| WCAG 2.1 / ISO 40500 | Technical spec from W3C, adopted as ISO. | SC 1.1.1 Non‑text Content: every informative image must have an equivalent text alternative. |
| EN 301 549 v3.2.1 | Harmonised EU standard referenced by all EU laws on digital accessibility. | Clause 9 maps directly to WCAG 2.1; alt text is mandatory for non‑text content. |
| WCAG 2.2 & draft 3.0 | Successor specs (2023 / in development). | Do not change the alt‑text rule; the requirement remains. |
3 | Regional & national regulations that reference alt text
| Region | Law / Regulation | What it says about images |
|---|---|---|
| European Union | European Accessibility Act (2019/882) – compulsory from 28 Jun 2025 for e‑commerce, banking, e‑books & more. | Digital products and services must conform to EN 301 549 → WCAG 2.1 alt‑text rule. |
| Web Accessibility Directive 2016/2102 (implemented via national laws such as Italy’s Legge Stanca). | Public‑sector websites/apps must meet WCAG 2.1 AA, including alt text. | |
| United States | ADA Title II Final Rule 2024 – state & local government web/mobile. | Requires WCAG 2.1 AA conformance; alt text examples provided. |
| Section 508 Refresh (federal). | Mirrors WCAG 2.0/2.1; Section508.gov offers detailed alt‑text guidance. | |
| Canada | AODA (Ontario) & Accessible Canada Act 2019 | Mandate WCAG compliance; alt text explicitly required. |
| United Kingdom | Equality Act 2010 + Public‑Sector Bodies Accessibility Regulations 2018 | Public sites must meet WCAG 2.1 AA → alt text. |
| Germany | BITV 2.0 | Criterion 1.1 requires “Alternativtexte” for images. |
| France | RGAA 4.1 | Criterion 1.1: every <img> needs an alt attribute. |
| Spain | Real Decreto 1112/2018 + UNE‑EN 301 549 | Same WCAG‑based duty. |
| Japan | JIS X 8341‑3:2016 | Maps 1‑to‑1 to WCAG; test 1.1.1 checks alt text. |
| China | GB/T 37668‑2019 | Aligns with WCAG 2.0 alt‑text rule. |
| Australia | Disability Discrimination Act + AHRC guidelines | Recommends WCAG to avoid discrimination. |
| Brazil | e‑MAG 3.0 | Directive 3.6: provide text alternatives for images. |
The common denominator? If an image conveys information, a meaningful alt text is legally required.
4 | Best‑practice checklist
- Is the image informative?— Yes → write alt text | No → use
alt=""or a CSS background. - Length ≤ 125 characters (many screen‑readers pause after ~150).
- Describe the purpose, not just the appearance.
- Avoid redundancy (“image of…”, file name, etc.).
- If the image is a link, state the destination (e.g., “Download PDF report”).
5 | How ImgSEO helps you comply
- Automatic WCAG‑compliant alt text on every upload.
- Bulk fixer – repair hundreds of legacy images in minutes.
- Context‑aware prompts – include post title & filename for higher relevance.
- 25+ languages for multinational sites.
- Dashboard log & CSV export for audit trails.
- Filename optimiser – turns “IMG_1234.jpg” into “organic‑coffee‑beans.jpg”, boosting SEO without breaking links.
Badge policy:
When you place the “Accessible with ImgSEO” badge on your site, you indicate that all non‑decorative images have meaningful alt text generated or manually reviewed with ImgSEO. This page summarises the regulations that such practice satisfies; it is informational only and not legal advice.
6 | Next steps
- Install the ImgSEO WordPress plugin or integrate the API in any CMS.
- Run an automated audit (e.g., WAVE, Axe) to confirm 0 errors for SC 1.1.1.
- Keep alt‑text governance in your content workflow — ImgSEO can alert editors when they forget.
Need assistance? Contact our team for bespoke accessibility reviews.
Further resources
- W3C: Understanding SC 1.1.1 – Non‑text Content
- ADA.gov Fact Sheet – Title II Final Rule 2024
- Section 508: Authoring Meaningful Alternative Text
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