WordPress image title, caption and three more fields: which ones actually do something

The five image fields in the Media Library

Click any image in Media → Library. A window opens with the attachment details and fields to fill in. The documentation for the Media Library screen describes them. The fields look similar, but each one ends up somewhere different.

We've written a separate post on alt text, with examples of good and bad descriptions: alt text in WordPress. Here we look at the other four fields, the ones you ask about when your library looks like a camera folder.

An IMG_2034 title: cosmetic or a problem?

More cosmetic than a problem. WordPress takes the title from the file name on upload, so a photo from your phone gets the title “IMG_2034”. In a typical theme this title doesn't make it into the page code, so Google doesn't read it.

The trouble is elsewhere. A library with a thousand IMG_ files is impossible to search. You're looking for a lantern photo for a new post and going through the thumbnails one by one. On top of that, a camera title almost always means nobody touched the alt text either, and that does affect Google and accessibility.

Thursday, 22:10. You open the library to give titles to the images from your last product shoot. File 37 of 400, each one needs a click, the product name typed in and care not to mix them up. We'll come back to work like this at the end.

Caption and description: which one is for whom

The caption is the only one of these fields every visitor sees, because the theme shows it under the image. Fill it in when the image needs explaining: who's in the photo, where it was taken, what the chart shows. Under a product photo on a white background a caption usually adds nothing.

The description only shows on the attachment page, a separate page with just the image. Since WordPress 6.4, new installs have these pages turned off, and the attachment address leads to the file. Older sites kept them after updating. The WordPress core team's note on changes to attachment pages gives the details. SEO plugins such as Yoast SEO and Rank Math usually redirect attachment pages too. In practice you can skip the Description field.

There's a catch with both fields, the same as with alt text. When you insert an image into a post, the caption is copied into the post content. A later change in the library won't fix older posts.

File name: change it before uploading

The file name is the only one of the five fields WordPress won't let you change in the library. According to Google's image guidelines, a good name gives a very slight hint about what's in the image. Google recommends short, descriptive names instead of generic ones like image1.jpg.

The weight of that hint is small, and the risk of changing it afterwards is considerable. Renaming an uploaded file changes its address, so the posts that use it need fixing and the old addresses need redirecting. So:

• name new images before uploading, for example wrought-iron-lantern-terrace.jpg,
• don't rename old files in bulk just for SEO,
• the exception is the odd image on your most important pages, if you're replacing it anyway.

How to tidy up image details step by step

In order from what helps most to what's cosmetic.

1. Find images without alt text. Start with those on the home page, in your offer, on products and in your most-read posts.
2. Fill in the alt text. It's the only field that really affects Google and accessibility.
3. Fix the titles of images that have camera names, so you can find them in the library.
4. Add captions only where readers need them: photos with people, places, charts.
5. Leave the Description field, unless your site has attachment pages turned on and needs them.
6. Set a naming rule for new files and stick to it every time you upload.
7. Check a few older posts to see whether the captions in the content match the library.

If your images weigh several megabytes each, take a look at our post on why WordPress is slow while you're at it.

How the chat tidies the Media Library in batches

In the morning you write one request, read the samples and approve a batch. The TellMyShop plugin for WordPress and WooCommerce finds images in the library with camera titles and no alt text. Your chat (Claude or ChatGPT) suggests alt text, a title and, if needed, a caption, based on the file name and the page or product the image is attached to. When that data doesn't make it clear what's in the image, it doesn't guess and sets the file aside for you.