Free Image Alt Text Checker

What Is the Image Alt Text Checker?

A free alt text checker is a tool that reads pasted HTML and reports on every image's alt attribute: which images have alt text, which are missing it, which carry an empty alt, and which trip the common quality flags. You paste markup from a draft, a local file or a staging page, and the tool lists each image with its source, its alt status and any flags, plus totals and a CSV export. If you want to check alt text in html before publishing, without handing over a live URL, this is the quick way to do it.

What Is It Used For?

Bloggers use it to catch missing alt text before a post goes live. Accessibility-minded editors use it to review a page's images in one pass instead of opening each one. Developers use it on template output and staging markup that no URL-based checker can reach. SEO editors use it because descriptive alt text helps search engines understand images, and missing alt is one of the most common on-page gaps.

Key Benefits

• Works on drafts and local files — paste HTML from anywhere, including pages that are not published yet.
• Missing vs empty, kept distinct — a missing alt attribute and an empty alt attribute are different things, and the report labels them differently.
• Real quality flags — file names used as alt, alt over 125 characters, and duplicate alt text across images are all flagged.
• Issues-only filter — hide the clean images and review only the ones that need attention.
• CSV export — take the full result table into a spreadsheet for fixing or sharing.
• Completely free and private — no signup, no limits, and nothing you paste ever leaves your browser.

How to Use This Free Image Alt Text Checker

1. Paste your HTML into the box — a full page or just the part that contains images.
2. Click Check Alt Text. The summary shows how many images were found, how many are missing alt, and how many carry an empty alt.
3. Read the list. Each image shows its source, its alt status (Missing alt, Empty alt, or Alt present) and any flags, such as filename-as-alt or duplicate alt.
4. Tick "Show issues only" to hide the clean images and focus on the ones that need fixing.
5. Click Download CSV for a spreadsheet of the whole result, then fix the flagged images in your own editor — this tool reports, it does not rewrite your HTML.

Common Mistakes to Avoid With Alt Text

• Treating empty alt as an error. An empty alt attribute (alt="") is the correct choice for a purely decorative image: it tells screen readers to skip it. Only a missing alt attribute is always a problem.
• Using the file name as the alt text. Alt text such as "IMG_2047.jpg" passes a presence check but tells a screen-reader user nothing about the image. Describe the image instead.
• Writing very long alt text. Alt over about 125 characters gets cut off by some screen readers, so the end of the description is never heard. Keep it short and to the point.
• Repeating the same alt on different images. Identical alt text on several images makes them indistinguishable to screen-reader users. Give each meaningful image its own description.
• Stuffing keywords into alt text. Alt text is for describing the image to people who cannot see it. Keyword-stuffed alt reads badly aloud and can look like spam to search engines.

Frequently Asked Questions

Is this alt text checker free? Yes, completely free — no signup, no usage limits, no account. Check as many pages of HTML as you like.

Is my HTML uploaded anywhere? No. Checking happens entirely in your browser, so your markup never leaves your device and is never stored on a server.

What is the difference between missing alt and empty alt? Missing alt means the img tag has no alt attribute at all, which is always a problem. Empty alt means the tag carries alt="" — an explicit statement that the image is decorative and should be skipped by screen readers. The report labels them differently because they mean different things.

Is empty alt an error? No. Empty alt is valid and correct for purely decorative images, such as spacers, dividers and background-style flourishes. It is only wrong when the image actually carries meaning that a visitor needs.

Why is a file name flagged as alt text? Because alt text such as "team-photo.jpg" describes the file, not the picture. A screen-reader user hears the file name and learns nothing about what the image shows, so the tool flags it for rewriting.

Why flag alt text over 125 characters? Some screen readers cut off alt text at around 125 characters, so anything longer may never be fully heard. Short, focused descriptions are safer and easier to understand.

Why flag duplicate alt text? When several images share identical alt text, a screen-reader user cannot tell them apart. Each meaningful image deserves its own description, even if the images look similar.

Can I check a live page by typing its URL? No. This tool checks pasted HTML only, because a browser page cannot fetch arbitrary websites — cross-origin rules block it. Copy the page's HTML source and paste it here instead.

Does it see images added by JavaScript? No. Only images present in the pasted HTML are checked. Images injected by scripts after a page loads are invisible to this tool, so check the rendered source if you need those too.

Does it judge whether alt text is good? No. It checks presence and the mechanical flags above, not quality. A short, accurate description and a vague one both pass; only you can judge whether the words actually describe the picture.

What is in the CSV export? One row per image, with its source, alt status, alt text and flags, so you can sort, filter and share the fixing list in a spreadsheet.

Does the tool fix my HTML for me? No. It reports what needs fixing; you edit the alt attributes in your own editor or content system and paste again to re-check.

Does it work on mobile? Yes. The tool runs in any modern mobile browser, and the layout adjusts to small screens, so you can paste and check from a phone.

Final Thoughts

Alt text is a small habit with a double payoff: a page that works for screen-reader users and images that search engines can actually understand. Paste your markup here, fix the flagged images, and make it part of your pre-publish routine.

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