AI Image SEO: automatic alt text for WordPress images

Generate accurate alt text, titles, and captions for your images with AI, on upload and across your existing library.

Plan: Business

On this page

What it does

AI Image SEO (ISM) writes descriptive alt text, image titles, and captions for your
WordPress images using AI, so your media is accessible and search-friendly without manual typing.
It can optimize images as you upload them, sweep your existing library in the background, and
fill in empty alt attributes inside posts you have already published. Every change is
reversible for 30 days.

How to use it

Run a sweep across your existing library

  1. Go to DefiniteSEO > AI Image SEO.
  2. Switch the module on and review the settings (post types, per-day cap, length limits).
  3. Select Start full sweep. A confirmation shows how many images will be processed and the
    estimated credits.
  4. Confirm to begin. Progress and counters (processed, pending, failed, skipped) update on the
    dashboard.

The AI Image SEO dashboard with sweep controls and counters

Optimize a single image

  1. Open an image in the Media Library.
  2. In the DefiniteSEO panel, generate alt text, title, and caption for that image.
  3. Accept and apply the suggestions you want.

Fill empty alt text in existing posts

Turn on inline propagation to copy generated alt text into empty alt="" slots in posts that
use the image. Use Scan posts and then Apply inline patches on the dashboard to review
and apply these changes.

Filename optimization on upload

The upload mode controls what happens to new images when you upload them:

  • Off: no filename changes on upload.
  • Lite: derives an SEO-friendly filename from keywords without using AI (no credits).
  • Full: uses GPT-4o vision to generate a descriptive filename (about 10 credits per image).

Note: Captions are page-visible text, so AI Image SEO never applies them automatically. It
shows the suggested caption with a copy button for you to paste where you want it.

Settings reference

Setting What it does Default Notes
Enable module Turns AI Image SEO on or off Off
Upload mode Filename handling for new uploads Lite off, lite (no AI), full (about 10 credits per image)
Generate captions Suggest captions (copy-only, never auto-applied) On Shown with a Copy button
Inline propagation Fill empty alt text in existing posts Off Modifies posts you did not edit
Inline post types Which post types inline propagation touches Post, Page
Per-day cap Maximum images generated per day 500 1 to 100,000
Alt max length Maximum characters in generated alt text 125 20 to 250
Title max length Maximum characters in generated titles 60 10 to 250
Skip small images Skip images narrower or shorter than this many pixels 50 0 to 4096
Allowed image types MIME types processed JPEG, PNG, WebP, GIF Add or remove types
Excluded images or posts Attachments or posts to skip None
Email digest Summary email of sweep activity On Set recipient

Limits and good to know

  • Plan: Requires the Business plan or higher, and the AI Image SEO dashboard card must be on.
  • Credits: Lite upload mode and mechanical steps are free. AI generation and Full filename
    mode (about 10 credits per image) use credits; the per-day cap keeps costs bounded.
  • Undo: Every change is reversible for 30 days from the Activity log.
  • Background behavior: Sweeps run in batches via WordPress cron; large libraries finish over
    several runs.
  • Captions: Suggested only, never auto-applied, since captions are visible on the page.

FAQ

How many credits does an image use?

Lite filename mode and non-AI steps are free. AI alt and title generation uses credits per
image, and Full filename mode uses GPT-4o vision at about 10 credits per image. Set a per-day
cap to keep spending predictable.

Will AI Image SEO overwrite alt text I already wrote?

No. Inline propagation only fills empty alt="" slots. Existing alt text you wrote is left in
place. You can also exclude specific images or posts.

Why are captions not applied automatically?

Captions are visible page text, so the module never inserts them for you. It generates a
suggestion and gives you a copy button so you decide where, if anywhere, the caption goes.

Can I optimize images as I upload them?

Yes. Set the upload mode to Lite (no AI) or Full (AI filename), and choose whether alt text is
generated on upload. Existing images are handled by the sweep.

Does it skip tiny images like icons?

Yes, if you set the skip-small-images threshold. Images smaller than the pixel size you choose
are skipped, so icons and spacers are not processed.