Alt text helps people using screen readers understand meaningful images, and it also gives search engines useful context about image content. The goal is not to fill every image with keywords. The goal is to describe useful images clearly while leaving decorative images appropriately empty.
Use the Image Alt Text Checker to review a public webpage and identify images that may be missing an alt attribute or need attention.
What the alt attribute is for
The HTML alt attribute provides a text alternative when an image cannot be seen or understood visually. Good alt text communicates the purpose or important information in the image in the context of the page.
For example, a product photo might need the product name and a useful visual detail. A chart may need the main conclusion. A decorative divider usually does not need a description.
Missing alt text vs empty alt text
These are not the same thing.
- Missing alt attribute: the image has no
altattribute at all. - Empty alt attribute: the markup includes
alt="", which is often correct for purely decorative images.
An automated checker can flag candidates, but a human still needs to decide whether the image is meaningful or decorative.
How to check a webpage
- Open the Image Alt Text Checker.
- Enter the public page URL you want to review.
- Run the check and review the image list.
- Prioritize meaningful images with missing or weak alt text.
- Update the page in your CMS and run the checker again.
How to write useful alt text
Keep alt text specific to the purpose of the image. Avoid phrases such as “image of” unless that information is important. Do not repeat nearby captions word for word, and do not force keywords into descriptions that would sound unnatural to a person using a screen reader.
A useful test is simple: if the image disappeared, what information would a visitor miss? That missing information is often what the alt text should communicate.
Common mistakes
- Using the same alt text for every image in a gallery.
- Stuffing SEO keywords into unrelated image descriptions.
- Describing decorative icons that should be ignored by assistive technology.
- Leaving important linked images without a useful text alternative.
- Assuming a filename automatically becomes good alt text.
Check the image itself too
Accessibility is only one part of image optimization. If an image is oversized for its display area, resize it with the Image Resizer. If file size is the problem, use the Image Compressor.
Practical review order
Start with homepage hero images, linked images, product images, diagrams, screenshots and charts. Then review lower-priority decorative media. This approach improves the pages users interact with most before spending time on minor assets.
Run a fresh scan with the UptimeFixer Image Alt Text Checker after your changes to confirm the obvious gaps have been addressed.