SEO
Image Alt Text Checker
Check every image on a page for missing, empty, or weak alt text. Scan a URL or paste HTML, get a score and an itemized list to fix. Free, no signup.
We fetch the page once, check it, and keep nothing. Pages that load images with JavaScript may show fewer images than you see in a browser.
✳ Free · No signup · Runs in your browser — we never store your numbers
Small business guide
What this tool helps you do
Use this free image alt text checker to see, in one pass, how every image on a page handles its alt attribute: which images have genuinely useful alt text, which are missing it entirely, which carry an empty alt (fine for decoration, a problem otherwise), and which have weak alt text — filenames, "image", or fragments too short to describe anything.
Alt text does two jobs at once. It's how screen reader users experience your images — a real accessibility obligation — and it's how search engines understand them, which is what gets your products and work photos into Google Images. Most sites fail quietly here because no one ever looks: the checker is the looking. Scan a URL, or paste HTML for a page that isn't public yet, and get an itemized fix list instead of a vague score.
How to use this tool
- 1
Enter the page URL and click check — or switch to "Paste HTML" for drafts and staging pages.
- 2
Read the score and the counts: good, weak, empty, missing.
- 3
Work the list from the bottom up: fix missing alts first, then weak ones.
- 4
For each meaningful image, write alt text that describes what the image shows in one natural sentence.
- 5
Leave alt="" only on genuinely decorative images (dividers, background flourishes) — that's correct, not lazy.
Examples
Product page with lazy CMS defaults
A boutique scans its best-selling product page.
Inputs
- Mode: Scan a URL
- URL: theboutique.com/products/linen-dress
Result
14 images: 3 good, 7 weak ("IMG_2041", "product-photo", "image"), 2 missing, 2 empty. Score 29/100, with each weak alt flagged and the reason shown — "Alt text is just the filename."
The CMS auto-filled filenames as alt text — technically present, practically useless. Rewriting seven alts ("Model wearing the sand linen midi dress, back view") took twenty minutes and made every product image eligible for Google Images searches.
Checking a redesign before launch
An agency checks a staging page that isn't publicly reachable.
Inputs
- Mode: Paste HTML
- HTML: the page source copied from the browser's view-source
Result
The same itemized report without needing the page to be live — 22 images, 4 missing alt, all in the new gallery component.
The gallery template was the systematic culprit — one component fix resolved all four. Scanning before launch turns alt text from a retrofit into a template-level habit.
Key terms
Alt text (alt attribute)
The written description of an image in HTML. Screen readers speak it, search engines index it, and browsers show it when the image fails to load.
Decorative image
An image that adds no information — a swirl, a divider, a background texture. The correct markup is an empty alt (alt=""), which tells screen readers to skip it silently.
Weak alt text
Present but useless: filenames ("DSC_1234"), generic words ("photo", "image"), or fragments too short to describe anything. Counts as filled-in to a CMS, counts as nothing to a screen reader or a search engine.
How to interpret the result
Read the score as coverage, not quality
The score measures how much of the page is properly handled: full credit for descriptive alts, half credit for empty alts (we can't see whether the image is truly decorative), nothing for missing or weak. A 90+ means alt text is under control; under 60 means images are invisible to screen readers and image search alike. The itemized list matters more than the number — it's your work queue.
Write alt text like you're on the phone
The reliable test: describe the image to someone over the phone in one sentence. "Barista pouring latte art at the counter" — not "coffee" (too little), not a keyword pile ("coffee shop best coffee austin coffee near me" — screen readers read that aloud, and it's miserable). Front-load what matters, keep it under 125 characters, and let it be natural language.
Common mistakes
- Letting the CMS auto-fill filenames as alt text and calling the job done.
- Stuffing keywords into alts — it reads terribly aloud and search engines discount it.
- Adding alt text to decorative flourishes ("elegant divider line") instead of using alt="".
- Describing the file instead of the content ("JPEG image") or starting every alt with "Image of…" — the screen reader already announces it's an image.
- Fixing the page once but not the template that generates the problem on every new page.
Frequently asked questions
Is this alt text checker really free?+
Yes — free, no signup, no limits beyond fair-use rate limiting. We fetch the page once, run the check, and store nothing.
Why does the checker show fewer images than I see on the page?+
The checker reads the page's HTML as served. Images injected later by JavaScript (some galleries, carousels, and app-built sites) aren't in that HTML. For those, use the Paste HTML mode with the rendered source: right-click the loaded page, Inspect, copy the outer HTML.
Is empty alt text (alt="") wrong?+
No — it's the correct markup for decorative images, telling screen readers to skip them. It's wrong on meaningful images (products, team photos, diagrams). The checker lists empty alts separately so you can make that call image by image.
Does alt text actually help SEO?+
Yes, two ways: it's the main signal for ranking in Google Images (real traffic for products, food, and portfolio work), and it adds context that helps the page itself. It's also an accessibility requirement — ADA-related lawsuits over inaccessible sites regularly cite missing alt text.
How long should alt text be?+
One natural sentence, under 125 characters — the point where some screen readers truncate. Long enough to describe what matters, short enough to respect the listener's time. The checker flags alts over that limit.
Can I check a page that isn't live yet?+
Yes — switch to Paste HTML mode and paste the page source. Nothing needs to be publicly reachable, and nothing you paste is stored.