How to Audit Image Alt Text Across an Existing Blog

Key takeaways

Inventory page-image uses, not just media files.
A missing attribute and an empty one are different findings.
Verify the live output after each group of fixes.

An alt text audit reviews how images are used across published pages, then assigns and checks the right fixes. Build an inventory of page-image pairs, name each image’s role, and review what the reader needs. Do not turn every empty attribute into a keyword phrase. The image SEO guide covers writing basics; this guide covers the audit of an existing blog.

Choose a clear audit scope

Start with a page set the team can actually review. It may be one cluster, a high-use template, or the articles for an key service. Record the date and public URLs. Do not call a sample of five pages a complete site audit. Keep the coverage honest.

Choose how to collect the list. A crawl, CMS export, or manual review can help, depending on the site. State what the method misses. An image loaded only after a click may need a separate rendered-page check. A tool’s list is a starting point, not proof that every image use was found.

Build a page-image inventory

Use one row per image use on a page. Record the public page, image source, visible context, current alt output, and whether the image is linked. The same file may occur several times with different roles. A list of unique media files alone will miss those differences.

Add the role, finding, proposed fix, owner, and check status. Keep values such as missing and empty distinct in the record. Do not let a blank spreadsheet cell silently mean both. A clear inventory helps the editor and developer understand the same task without guessing.

Run the alt text audit by role

Open the page and ask what the image does. It may convey a fact, act as a link, add decoration, or repeat text already available nearby. Use that role to decide the needed alternative. Do not classify an image by file name or visual style alone.

A decorative separator can be intentionally empty. A linked image may need a useful name for the destination or action. A complex diagram may need more than a short phrase. These are different cases. A rule that simply fills all empty fields can create noise and still miss the key work.

Separate three common findings

First, name a missing alt attribute. Next, name an empty attribute and decide whether that is intentional for the role. Finally, review nonempty text for meaning and truth. “Image123” is present text, but it is not necessarily useful to the reader.

Keep the proposed correction clear. A missing attribute may need a template fix. An incorrect description may need an editorial change. A diagram with no full explanation may need nearby content. The inventory should say what to change and where, not only mark the row as failed.

Check dense graphics and words inside images

For charts and detailed diagrams, use the chart-description review to decide whether a short identifier and fuller explanation are needed. Do not call the image fixed just because its alt field now contains a sentence. The reader still needs the key data or relationship.

For text-heavy posters and screenshots, follow the images of text process. A long text passage may need to become normal page content. Copying it into one hard-to-use field is not always the right fix. Keep the alternative tied to the actual task.

Review product images and reused assets

A product image can show a whole item, a detail, or a variant. Check that the wording matches the view and page context. The product-image workflow helps separate a wrong item from a text-only fault. Alt text cannot repair a photo of the wrong model.

Review repeated files on each useful page. A media-library change may affect some uses but not others. An embedded image may store its own text in the article. Check the actual output rather than assuming one edit in the library updated the whole blog.

Example: three rows need three different fixes

Imagine a fictional blog with a decorative divider, a linked guide cover, and a chart. The divider has an intentional empty alternative. The linked cover has a filename as its only name. The chart has a short label but no accessible values. This is an audit example, not a tested client result.

The team leaves the divider’s role-based choice in place, improves the linked cover’s name, and adds the chart’s key text and data. It does not apply the same sentence to all three. The record preserves why each decision was made, so the next reviewer can follow it.

Prioritize by the task being blocked

Fix images that carry key meaning or form an unclear control before low-value cosmetic cases. A shared template fault may affect many pages and deserve early attention. Record its scope and test a useful sample after the change. Do not claim that one tested page proves every use is fixed.

If an asset adds no useful content, consider replacing or removing that use through the normal editorial process. The visual selection guide helps decide whether the image belongs. The audit is not required to preserve an unnecessary visual just because it has a place in the media library.

Verify the published fix

After the edit, wait for the public version to update. Reopen the page in the same useful state and inspect its image output. Confirm both the words and the role. A saved field in the CMS is not the final test of what a visitor or assistive tool receives.

Retest shared cases when a template changes. Check that intended empty values stay empty and meaningful alternatives stay correct. Keep the check date and coverage in the working record. A useful status says what was verified rather than giving a broad accessibility pass.

Use a small release-check list

Keep one row for each test page. Note the image, its job, the old output, and the new output. Mark what you expected and what you saw. A row should say “linked cover now has the guide’s name,” not just “image fixed.” That makes the check clear to the next person.

Include a case that should stay empty. If a shared fix adds text to all images, this row can show that the change was too broad. Keep a chart case too. Its short label may be right while its data still needs a readable table. A small set of different uses is more useful than testing the same kind of photo five times.

Keep the audit part of content maintenance

DEX can generate images within an article workflow and supports page-quality checks. Those checks can help flag work, but a score does not establish that every image’s meaning and purpose were reviewed. Give a person the role-based decisions and check any generated wording before publication.

Use the same small inventory for future updates. Add changed or new uses, assign the next corrections, and close the rows you actually verified. The audit should produce usable fixes on real pages. It should not become a large count of missing fields with no explanation of what the reader needs.

FAQ

Can a checker judge whether every alt text is right?

It can find patterns, but a page-context review is needed for meaning and function.

Should every empty alt attribute be filled?

No. Decide whether the image is decorative, redundant, informative, or functional.

Is fixing the media library enough?

Not always. Check what each published page actually outputs.

Sources

Alt decision tree · W3C
Complex images · W3C

Dex SEO

Dex SEO is an AI SEO agent for small businesses. Every article here is planned from search data, drafted by Dex, fact-checked against the sources it cites, and reviewed by the team before it is published.

How this article was made: planned and drafted by Dex from search data, fact-checked by Dex (5 claims checked), then approved by the Dex SEO team.