---
title: "Add alt text to images"
description: "Alt text describes an image for people who cannot see it and for crawlers that cannot read pixels. Write what the image shows in context, keep it under about 125 characters, and use an empty alt for decorative images. Make alt text a required field on upload."
url: "https://seo-mcp.io/t/add-alt-text-to-images"
---

# Add alt text to images

Alt text describes an image for people who cannot see it and for crawlers that cannot read pixels. Write what the image shows in context, keep it under about 125 characters, and use an empty alt for decorative images. Make alt text a required field on upload.

## Prerequisites

- A crawl of rendered images
- Access to the CMS image fields

## Steps

1. **List images without alt text** *(general best practice)* — Crawl the site and export every img element with its src, alt value and page. Separate missing alt from empty alt, because decorative images should be empty.
   Check: The export distinguishes images with no alt attribute from those with alt="".
2. **Write contextual descriptions** — Describe each informative image in one sentence, including the detail that matters on that page. Keep decorative images empty and avoid duplicating adjacent captions.
   Check: Sampled informative images have unique alt text that is not a filename or keyword list.
3. **Require alt text on upload** *(general best practice)* — Make the CMS field required, or validate in the build that informative images have alt text. Fail the build on missing alt for content images.
   Check: Uploading an image without alt text is blocked or fails the build.

## Source

@seo-mcp on 2026-10-19: https://developers.google.com/search/docs/appearance/google-images

Canonical: https://seo-mcp.io/t/add-alt-text-to-images