SEO6 min read·Updated

Image Alt Text Best Practices (With WebP Files)

Converting to WebP does not rewrite alt text. If you replace a file in the CMS, copy the alt first. Write alt for humans and screen readers; search engines come along for the ride.

Alt describes the image, not the format

alt="red kettle on a wooden table" is correct. alt="webp image kettle SEO buy" is not. Decorative borders get alt="".

Why it matters

  • WCAG requires text alternatives.
  • CMS file replace often clears alt.
  • Google Images uses alt as a hint, not a magic tag.

How to do it

  1. Before bulk replace, export a list of filename → alt.
  2. Convert files. Re-upload or replace. Paste alt back.
  3. Skip alt on purely decorative shapes.

Captions vs alt

Captions are visible and can add context. Alt should still make sense if the image fails to load. Do not duplicate a long caption into alt.

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Put it into practice

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Frequently asked questions

No.

A short sentence. Not a paragraph, not two words if the image is complex.

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