How to add alt text to images in WordPress

Add alt text by hand

WordPress stores alt text on each image. There are two places to set it:

1. Media library: go to Media → Library, click an image, and fill in the Alternative Text field in the attachment details. This becomes the default whenever the image is inserted.
2. Block editor: select an Image block, open the block settings sidebar, and edit the Alternative text field. This applies to that one placement of the image.

The two are separate: an Image block keeps the alt text it had when the image was inserted. If you update an image in the media library later, check the posts that already use it.

Leave the field empty only for purely decorative images — WordPress then outputs alt="" and screen readers skip the image. See WCAG alt text requirements for when that is correct.

Generate alt text with the AltVision plugin

AltVision – AI Alt Text Generator is a free plugin from the WordPress.org directory. It looks at the image and at the headings, paragraphs and captions near it on the page, so the description fits what the image is doing in the content.

1. In your dashboard, go to Plugins → Add New, search for AltVision, then install and activate it. No API key is needed for the free version.
2. Open Settings → AltVision to choose the default language for generated alt text (31 languages are supported) and whether surrounding page text is used as context.
3. In the media library, open an image and click Generate Alt Text. In the block editor, select an Image block and use Generate alternative text in the Alt Text Generator panel of the sidebar.
4. Read the suggestion and edit it if needed — it is saved to the image's Alternative Text field like any alt text you type yourself.

The plugin also works in the Elementor editor and with images served from a CDN, as long as the image URL is publicly accessible. It supports JPG, PNG, WebP, GIF and AVIF.

Fix alt text across the whole media library

AltVision adds an Alt Text Manager item to the admin menu. It lists every image with its current alt text and a proposed one, with counts for all assets, those with alt text and those missing it.

• Click No Alt Text to see exactly which images need work.
• Select images, generate proposed alt text, review it in the table, and apply the ones you accept.
• Premium plans process many images at once, including the whole library, and can generate alt text automatically when an image is uploaded.

Free and premium limits

The free plugin generates alt text for 10 images per day, one at a time. Premium raises that to 500 images per day and adds bulk processing, generation on upload and a custom output style. You can also buy credits without a subscription.

Questions

Where is the alt text field in WordPress?

In the media library, open an image and use the Alternative Text field in the attachment details. In the block editor, select the Image block and find Alternative text in the block settings sidebar.

Does changing alt text in the media library update existing posts?

No. An Image block keeps the alt text it had when the image was inserted. Update the block in each post, or re-insert the image.

Can WordPress generate alt text automatically?

Not on its own. A plugin such as AltVision generates alt text from the image and its surrounding content, either per image or, on premium plans, automatically on upload and in bulk.