Générateur de texte alternatif par IA

Utilisez notre Générateur de texte alternatif par IA gratuitement. Aucune inscription requise.

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Le texte alternatif sert deux publics : les lecteurs d'écran (accessibilité) et les moteurs de recherche (SEO). Le rédiger manuellement pour 50 images produit, photos de blog ou posts sociaux est la tâche fastidieuse que tout le monde saute. Ce générateur de texte alternatif par IA analyse n'importe quelle image et produit un texte alternatif clair, descriptif et conforme aux normes WCAG en quelques secondes — sans inscription, utilisation illimitée.

What good alt text actually says

Strong alt text describes what's in the image and why it matters to the page. Not 'a photo of a dog' — too vague. Not 'image1234.jpg' — useless. Better: 'Golden retriever mid-leap catching a frisbee at sunset on Santa Monica beach'.

The rule: if you removed the image, what sentence would the visitor need to understand the page? That sentence is your alt text. The generator analyzes the image content and outputs alt text at the right specificity level (75-125 characters is ideal — long enough to be specific, short enough that screen readers don't drone on).

Alt text for accessibility (WCAG)

WCAG 2.2 requires meaningful alt text for any image that conveys information. Decorative images (purely visual, no content meaning) should have alt='' (empty), which tells screen readers to skip them — not a missing alt attribute, which screen readers will read as the filename.

The generator includes a 'decorative' toggle. When on, it outputs empty alt for purely visual elements (dividers, background flourishes). When off (default), it describes the image content for screen-reader users.

Alt text for SEO

Search engines use alt text as a strong ranking signal for image search and as a contextual signal for the page. Three SEO best practices: (1) Include the primary keyword naturally — not stuffed. 'Red running shoes on track' is better than 'best red running shoes for women cheap'. (2) Match the alt text to the image's actual content — Google penalizes deceptive alt text. (3) Vary alt text across images on the same page — identical alt text on every image signals low quality.

The generator can take an optional page-context input to tune alt text toward the page's primary keyword.

Alt text on Instagram

Instagram auto-generates alt text using its own AI (often wrong or generic). You can override it manually when posting: Advanced Settings → Write Alt Text. The override is read by screen readers and counts toward Instagram's accessibility score for the account.

For branded posts with text overlays, custom alt text matters even more — Instagram's auto alt text often misses text in images. Use the generator to write custom alt text before posting; paste into the Advanced Settings field.

Conseils pour tirer le meilleur parti de cet outil

  • Keep alt text under 125 characters. Screen readers can drone — long alt text loses listeners.
  • Lead with the most important detail. Screen readers read sequentially; front-loaded info wins.
  • Use alt='' for purely decorative images. Don't omit the attribute entirely.
  • Don't start with 'Image of...' or 'Picture of...' — screen readers already announce that.
  • Re-audit alt text quarterly. New images often get added with no alt text.

Questions fréquentes

Is the AI alt text generator free?

Yes. Free, no signup, unlimited use. Upload an image, get accessible alt text instantly.

What's the ideal length for alt text?

75-125 characters. Long enough to be specific (not 'photo of dog'), short enough that screen readers don't drone past attention span.

Does this work for Instagram alt text?

Yes. Generate alt text from your image, then paste it into Instagram's Advanced Settings → Write Alt Text before posting.

What's the difference between alt text and image titles?

Alt text is for screen readers and search engines (required for accessibility). Image titles show as tooltips on hover (mostly decorative, rarely needed). Always include alt text; titles are optional.

Will good alt text help my SEO?

Yes. Search engines use alt text as a ranking signal for image search and a contextual signal for the page. Descriptive, keyword-relevant alt text (not stuffed) improves both.

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