Bulk generate missing image alt text with AI

Find every image with no alt text, write descriptive alt for each, and fix the copies already embedded in your posts.

Difficulty Intermediate

Time ~20 min

Tools run_wp_cli, rest_api

Prerequisites

A connected site with images in the media library, and a recent backup since this writes to attachments and post content.

The prompt

Audit my WordPress media library for images with missing alt text and help me fix it. Work in two phases and write nothing in phase one.

Phase 1, report only:
- Find every image attachment that has no alt text.
- Also scan my published posts and pages for embedded images whose alt attribute is empty, since alt is copied into content when an image is inserted and fixing the library will not fix those.
- For each image, propose a short, descriptive alt line based on what the image shows, describing it in context rather than stuffing keywords.
- Show me the full list: the image, where it is used, and your proposed alt. Then stop.

Wait for me to confirm. I will take a backup before you write anything.

Phase 2, after I approve:
- Write the approved alt text to each media library image.
- For each embedded image with an empty alt, add the alt attribute in place, editing only that img tag and leaving the rest of the content untouched.
- When you are done, list every image you updated and where, so I can spot-check.

Already connected to WPVibe?

Skip the copy-paste. Just ask your AI for the “Bulk generate missing image alt text with AI” recipe, or describe the task, and WPVibe runs these steps on your own site.

Alt text is the line a screen reader announces and a search engine reads when it cannot see the picture, and most media libraries are full of images that never got any. Writing it one image at a time in the admin is dull work, so it quietly never happens. There is also a hidden trap: alt text is copied into a post at the moment you insert an image, so fixing it in the media library later does nothing for the images already sitting in your published posts.

This recipe has your AI audit the media library and list every image missing alt text, then write a plain, descriptive line for each based on what the image shows. It also handles the trap. It scans your posts for embedded images with an empty alt attribute and fills those in too, editing each img tag in place so nothing else on the page shifts. It shows you the proposed alt text for review and writes nothing until you approve.

Paste the prompt and let it return the list first. Review a sample of the proposed alt before you approve, because good alt describes the image in its context and does not stuff keywords. Take a backup first, since this writes to both your media library and your post content. Then let it run and spot-check a few of the results.

Outcome

Descriptive alt text on every image that lacked it, in the media library and in the images already placed inside your posts.