How to Add Alt Text in WordPress (4 Methods, Step by Step)

Adding alt text to your WordPress images is one of the simplest yet most impactful things you can do for your website's SEO and accessibility. Yet studies show that over 65% of WordPress sites have images with missing alt text. This guide walks you through four different methods to fix that, from manual editing to full automation.

Method 1: Media Library (Manual)

The most straightforward way to add alt text is directly in the WordPress Media Library. This is ideal when you're uploading a few images and want full control over the descriptions.

1. Go to Media → Library in your WordPress dashboard
2. Click on any image to open the Attachment Details panel
3. Find the "Alt Text" field on the right side (sometimes labeled "Alternative Text")
4. Type a descriptive, concise description of the image (80-150 characters)
5. The alt text saves automatically — no need to click a save button

Method 2: Block Editor (Gutenberg)

When writing a post or page, you can add alt text directly in the Gutenberg block editor without leaving your content.

1. Click on an image block in your post/page
2. Look at the Block Settings panel on the right sidebar
3. Under "Settings", find the "Alt text (alternative text)" field
4. Type your description
5. Update or publish the post

If you're using the Classic Editor, click on the image, then click the pencil icon to edit, and you'll find the alt text field in the Image Details dialog.

Method 3: Bulk Editing with Plugins

If you have hundreds of images that need alt text, editing them one by one isn't practical. Several plugins help with bulk operations:

Image Attributes Pro can automatically set alt text based on the image filename, post title, or Yoast focus keyword. It's rule-based (not AI), so the quality is limited, but it's a fast way to fill in basic alt text across your entire library.

BIALTY is a free plugin that copies your Yoast SEO focus keyword or post title into the alt text field. Quick and easy, but the descriptions are generic and not based on what the image actually shows.

Method 4: AI Automation with SightSEO

The most effective method for large sites is AI-powered automation. Unlike rule-based plugins that just rearrange existing text, SightSEO actually analyzes what's in each image using computer vision and generates a unique, descriptive alt text.

1. Create a free SightSEO account (25 credits, no card)
2. Download and install the SightSEO plugin in WordPress
3. Go to SightSEO → Settings and enter your license key
4. Enable Auto-generate on upload — every new image gets alt text automatically
5. For existing images, click "Bulk Generate" to process your entire library at once

SightSEO also integrates with your SEO plugin (Yoast, Rank Math, etc.) to naturally include your focus keyword in the generated alt text, and with WooCommerce to include product names and categories.

How to Fix Existing Images with Missing Alt Text

Most WordPress sites have accumulated hundreds of images over the years, many without alt text. Here's a priority-based approach:

1. Product images first — These directly impact revenue through Google Shopping and Image search
2. Blog featured images — These appear in search results and social shares
3. Homepage and landing page images — These get the most traffic
4. Content images in popular posts — Check your analytics for your top 20 posts and fix those first
5. Everything else — Use bulk processing for the rest

How to Check for Missing Alt Text

Before you fix the problem, you need to know its scope. Here are three ways to audit your site:

Screaming Frog (free for up to 500 URLs): Crawl your site, go to the Images tab, and filter by "Missing Alt Text". This gives you an exact count and list of all images without alt text.

SightSEO Free Scanner: Use our free alt text tool to check any page for missing alt text.

Browser DevTools: Right-click any image → Inspect → check the alt attribute. Quick for spot-checking but not practical for site-wide audits.

Alt Text Writing Tips for WordPress

For more examples, read our Alt Text Best Practices guide with 15 real-world examples.