Image Alt Checker by Traffsite

An image alt checker reads the images on a page and reports the text in their alt attributes. The Traffsite image alt checker can also show the file name, image URL, dimensions and surrounding caption, so you can review alt text at scale instead of inspecting each image by hand.

Alt text is the description a browser or screen reader can announce when an image cannot be seen. Google uses it, together with computer vision and the page content, to understand what an image is about. When an image sits inside a link, Google can use the alt attribute as anchor text for that link, so a vague description costs more than it looks.

Images also fail in quiet ways. Missing alt attributes produce no visible change on the page. Repeated descriptions look fine until you read them. CSS background images can look like content but are not indexed by Google. A scan brings all of these into one list.

• Content audits. Older articles often have images with no description or a file name pasted in as a placeholder.
• Accessibility reviews. Screen readers announce alt text, so gaps affect real people, not only search engines.
• Product catalogue cleanups. Variants and colour swatches are easy to describe once and then duplicate everywhere.
• Site migrations. A new template can drop alt attributes or move images into CSS, and the loss is invisible in a browser.
• Template fixes. One weak component can affect thousands of pages, and the checker shows how widespread it is.
• Image search reviews. If image traffic matters, review descriptions and file names alongside the sitemap.

Context. Alt text works best when it describes the image as it appears on that page, not as a generic label. The checker shows the image next to its description and surrounding text, so you can judge whether the words match its role. The same photo might be the main subject of a recipe page and a small detail on a history page.

Consistency. Google asks for useful, information-rich descriptions that use keywords appropriately and warns that stuffing alt attributes with keywords can hurt the experience and may be treated as spam. A scan makes repeated phrases and stuffed lists obvious, which is hard to see one image at a time.

Technical checks. Google finds standard image elements with a src attribute. The checker reports the image URL and response code, so you can see whether the file is reachable. Accessibility matters too. Clear alt text helps people who use screen readers or have low bandwidth, a worthwhile result on its own. Search visibility is a companion benefit, not a promise.

The report lists results image by image: the thumbnail, its alt text, a status (missing, empty, weak or good), the image URL and response code. You can sort by status to fix the biggest gaps first and spot repeated descriptions across the page at a glance.

The aim is a set of images that are described, reachable and consistent:

• Every meaningful image has a short description that makes sense on its own.
• Decorative images use an empty alt attribute, so assistive technology can skip them.
• Linked images have alt text that works as anchor text for the destination.
• File names are short and descriptive instead of camera defaults, such as IMG00023.JPG.
• Captions and nearby text support the image rather than repeating the alt text word for word.
• Important images appear in a sitemap, including files served from a CDN.

You also get a faster review cycle. Once patterns are fixed in the template and CMS, new images inherit better defaults, and the next audit starts from a shorter list.

Why use a checker rather than spot checks?

• Finds invisible gaps. Missing and empty alt attributes do not change how a page looks, so they survive visual reviews.
• Catches stuffing. Repeated keywords and long lists stand out in a table, even when spread across a page.
• Respects context. Reviewing the image and caption together leads to better descriptions than writing from the file name alone.
• Covers templates. One scan shows whether a component produces weak alt text across many pages.
• Supports several teams. Editors, designers and developers can work from the same list.

1. Enter the page you want to review and start the scan.
2. Sort by missing alt text first. These images have no description at all, which is the clearest gap.
3. Review empty attributes. Keep them for decorative images, and add text where the image carries information or sits inside a link.
4. Look at each image in context. Check the caption and nearby paragraph, then write one concise sentence describing the subject and its role.
5. Remove repeated keywords and generic phrases. A description that would fit any image is probably too vague.
6. Fix the source, whether that is the page, the CMS field or the template, then run the Traffsite image alt checker again to confirm the change.

For large sites, fix the template first. Otherwise the next batch of content will recreate the same problem.

• Content editors: add images to articles and product pages.
• Accessibility teams: review what screen readers announce.
• SEO specialists: include images in technical audits.
• Developers: control templates, image elements and sitemaps.
• Ecommerce teams: manage large catalogues of product photos.
• Agencies: need a repeatable image review for each client.

You do not need to be an accessibility expert to start. Describe what matters in the image, keep it short, and use empty alt text when the image adds nothing. The checker shows where those rules were missed.