Image Alt Text Checker

What is image alt text?

Alt text (the alt attribute) is a short written description of an image. It is read aloud by screen readers for people who cannot see the image, shown if the image fails to load, and used by search engines to understand what the image shows. Good alt text helps your images appear in Google Images and makes your site accessible to everyone.

For example: <img src="dallas-plumber-van.jpg" alt="Plumber unloading tools from a branded van in Dallas">

What this alt text checker finds

The tool scans all <img> tags on the page and sorts them into groups:

• Missing alt: the attribute is not there at all. These need fixing.
• Empty alt (alt=""): correct for purely decorative images such as dividers and background shapes, so screen readers skip them.
• Weak alt: text that is just a file name, a word like "image" or "photo", or longer than 125 characters.
• Good alt: a real description.

It also tells you how many images use lazy loading and how many have no width and height, which can cause the layout to jump while the page loads.

How to use it

1. Enter the page URL and click Check images, or paste HTML into the second tab.
2. Read the summary numbers, then scroll the table. Each row shows a preview, the image file, its alt text and a status.
3. Add or improve alt text in your CMS. In WordPress, open the Media Library and fill in the "Alternative Text" field.

How to write good alt text

• Describe what matters in the image in one short sentence.
• Be specific: "Red 2024 Toyota Camry parked outside our Houston showroom" beats "car".
• Include a keyword only when it fits naturally. Never stuff keywords.
• Skip "image of" at the start. Screen readers already announce that it is an image.
• Use empty alt for decorative images, not missing alt.

The W3C images tutorial has a helpful decision tree, and Google's image SEO best practices cover file names and placement.

Large images slow pages down, so after fixing alt text, shrink your files with the Image Compressor and measure the result with the Page Size Checker.

Alt text for different image types

Product photos: include the product name, color and key feature. Team photos: name the people and their roles. Charts: summarize the main point the chart shows. Logos: use the company name. Buttons made of images: describe the action, such as "Call now". Check the rest of your on-page SEO with the Heading Checker and the Meta Tag Checker.

Alt text examples: bad, better, best

The best alt text describes what the image shows and why it is on the page, in one short sentence.

Image SEO beyond alt text

Alt text is one part of image SEO. To help your images rank in Google Images and load fast:

1. Use descriptive file names, such as black-leather-office-shoes.jpg instead of IMG_4821.jpg. The Slug Generator can turn a phrase into a clean file name.
2. Compress images before uploading. Large photos are the most common reason pages are slow. Try the Image Compressor.
3. Resize to the size you display. Do not upload a 4000-pixel photo for a 600-pixel slot; use the Image Resizer.
4. Use modern formats such as WebP where possible, with the Image Converter.
5. Place images near related text, because Google uses the surrounding content to understand them.
6. Set width and height attributes so the layout does not jump while images load.

Google's image SEO best practices cover these points in more detail.

Alt text and the law

In many countries, accessibility is a legal requirement for some websites, particularly government, education and large commercial sites. The international standard is WCAG, and one of its basic rules is that every meaningful image needs a text alternative. Even when it is not required, accessible sites reach more customers.

Writing alt text at scale

Large shops and blogs may have thousands of images. Prioritise:

• Product images and images on your top landing pages first.
• Images that carry information, such as charts, infographics and screenshots.
• Linked images, where the alt text acts as the link text.

AI tools can suggest alt text, but always review it. A machine may describe "a man smiling" when the important detail is the product he is holding.

Example: auditing a product category page

Run the checker on a category page of an online shop. The report lists 24 product images: 16 have alt text like "IMG_2045", 5 have no alt attribute, and 3 have good descriptions. Fixing them is simple: give each product image its product name plus one key detail, such as colour or material, for example "Brown leather wallet with coin pocket". Recheck the page afterwards to confirm every image now has meaningful alt text.

Last updated: October 25, 2026