WordPress allows you to add Alt Text in two main places: directly inside a post (for a specific instance) or in the Media Library (for global management).

1. The Modern Method (Block Editor / Gutenberg)

This is the standard way to edit images in WordPress versions 5.0 and above.

• Select the Image: Click on the image block within your page or post editor.
• Open the Sidebar: Look at the Block settings panel on the right-hand side of the screen. (If you don’t see it, click the “Settings” cog icon ⚙️ in the top right).
• Locate the Field: You will see a text box labelled “Alternative text (alt text)”.
• Enter Your Text: Type your description.
• Save: Update or Publish the post.

   

2. The Global Method (Media Library)

Use this method when you upload a new image before you insert it into a post.

• Navigate: Go to your WordPress Dashboard > Media > Library.
• Select Image: Click on the image you want to edit. A “Attachment Details” window will open.
• Edit: Find the “Alternative Text” field on the right-hand side.
• Save: It saves automatically as you type (you will see a “Saved” spinner).
  
  

Adding alt text in the Media Library after you have already inserted the image into a post will not update the post. You must edit the post manually to update the alt text there.

3. The Classic Editor Method

If you are still using the “Classic Editor” plugin:

• Click the Image: Click the image inside the visual editor.
• Click the Pencil: Select the “Edit” (pencil icon) button that appears.
• Edit: Type your text in the “Alternative Text” field in the popup window.
• Update: Click the blue “Update” button.

   

The “Decorative” Exception

It is crucial to know when not to add text.

The Rule: If an image is purely decorative (like a swooshy border, a divider line, or a background shape that adds no information), you should leave the Alt Text empty.

“If an image is purely decorative, it should be implemented so that it can be ignored by assistive technology.”

In WordPress, leaving the field explicitly empty tells screen readers to skip the image entirely, rather than annoying the user by reading out “image-552.jpg”.