Which SEO tools analyze alt text effectiveness?

General SEO crawlers (Moz, Ahrefs, Semrush) flag missing alt on crawled pages. For quality analysis — generic, duplicate, too-short detection with a score — Filikod is, to our knowledge, the only WordPress tool that measures alt text rather than just counting it. Its online checker also works on non-WordPress sites.

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Comparison 2026

The Best Alt Text Plugins for WordPress: an Honest Comparison

Q: What are the best plugins for managing alt text in WordPress?

It depends on the job. To audit and fix existing alt text without credits: Filikod (free). To auto-generate descriptions with AI at scale: AltText.ai (paid credits, images sent to an API). To fill alt from file names in bulk: Image Attributes Pro or Bialty (free tiers). No single plugin is best at everything.

Q: Are AI alt text generators worth it?

For large libraries where any description beats none, they save real time — budget for credits and accept that images transit through a third-party API. Review the output: unedited AI alt text tends toward the generic, and duplicates are common on similar images.

Q: Why does auto-generation create duplicate alt text?

File-name-based tools copy the same source string to every size and variant of an image, and AI tools describe similar images identically. Either way you get one description on many images — which is itself an accessibility and SEO defect. That is why an audit layer matters, whatever generator you use.

Five plugins, three philosophies and one table, data checked August 2026.

The best alt text plugin depends on the job. Filikod audits and scores your existing library for free. AltText.ai generates descriptions with AI on paid credits. Image Attributes Pro and Bialty fill alt text from file names. The market splits into generators and auditors, and they solve different problems.

The table

Five plugins side by side

« Quality audit » means the plugin evaluates existing alt text (missing, generic, duplicate) rather than just checking whether the field is filled. The third-party column matters for GDPR: AI generation requires uploading your images to an external API.

Plugin	Model	Quality audit	Free bulk edit	Images sent to a third party
Filikod	Free, no credits	✓ 0–100 score	✓	Never
AltText.ai	AI credits	Scanner (25 pages)	—	Yes (AI API)
Image Attributes Pro	Freemium	—	✓	No
Bialty	Freemium	—	✓	No
ImageSEO.io	5–60 €/month	—	—	Yes (AI API)

Philosophies

Three ways to think about alt text

Behind the feature lists, these five plugins follow three distinct approaches.

Generate with AI

AltText.ai and ImageSEO.io write descriptions with a model. Fast on large catalogs, but you pay per credit, your images transit through an external API and the output still needs review.

Copy from file names

Image Attributes Pro (100,000+ installations) and Bialty fill the alt field from the file name. Free and instant, but mechanical: IMG_4832.jpg becomes an alt that reads « Img 4832 ».

✳

Audit first

Filikod measures what exists, classifies every issue and lets you fix in bulk with human review. Slower than blind generation, and every alt is deliberate.

2,449

images audited in our benchmark

10.4%

carry generic or duplicate alt text

25.2%

have no alt text at all

The catch

The uncomfortable fact about auto-generation

File-name plugins mechanically produce the two defects our checker flags most often after missing alt: generic alt text (a file name is not a description) and duplicate alt text (one string copied across every size variant). AI has its own version of the problem, similar images get described identically.

Across the 2,449 images of our benchmark, generic and duplicate alt together account for 10.4% of all images, defects that mostly did not exist before a tool created them. Generation without an audit layer turns one visible issue into two hidden ones.

Our pick

✳

Which one should you install?

To clean an existing library for free and keep control over every word, install Filikod. For a huge product catalog with no time to write, an AI generator can help, followed by an audit pass to catch the generic output.

Whichever you choose, measure before and after. The ALT Quality Score gives you a number to attach to an accessibility statement or an SEO report, whoever wrote the text.

FAQ

Frequently asked questions

What are the best plugins for managing alt text in WordPress?

It depends on the job. Filikod audits and fixes your existing library for free. AltText.ai generates with AI on paid credits, and your images transit through its API. Image Attributes Pro and Bialty bulk-fill from file names with free tiers.

Which SEO tools analyze alt text quality?

General SEO crawlers flag missing alt but stop there. Filikod is, to our knowledge, the only WordPress tool that measures alt text quality rather than just counting it, and its free checker also works on non-WordPress sites.

Are AI alt text generators worth it?

For large libraries where any description beats nothing, they save real time. Budget for credits and API transfers, then review the output: unedited AI alt text tends toward the generic, and duplicates are common on similar images.

Why does auto-generation create duplicate alt text?

File-name tools copy the same string across image sizes and variants, and AI describes similar images identically. Both end with one description on many images, which is a defect for accessibility and SEO alike.

Another question?

The full FAQ covers the checker, the score, the plugin and how your data is handled.

Start by measuring

Before installing anything, run the free checker on your site. In two minutes you will know which philosophy your library actually needs.

Alt text audit and bulk management for WordPress. Quality score, bulk fixing, accessibility. Built in France by Lyode.