Image Alt Text Checker
Every Image, Judged In Words
This image alt text checker reads every image on a live page and says, for each one, whether its alt text helps a listener. It flags missing alt, file names and generic words, and it tells linked images apart from decoration.
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Image Alt Text Checker
Every image on a page, the alt text it carries, and the alt text it is missing
- Images
- 0
- No alt at all
- 0
- Marked decorative
- 0
- Needs work
- 0
- Already fine
- 0
| # | Image | Alt text | Verdict | What to do |
|---|---|---|---|---|
| Paste an address above and the images land here. | ||||
Ready. Paste any public address and this server reads the images on it once.
The Job Alt Text Does on a Page
Alt text is the sentence that stands in for a picture when the picture cannot be seen.
Screen readers read it out to blind visitors. A browser shows it when the file fails to load. Search engines also read it, because it is the clearest statement of what an image shows.
So the question is never only whether an image has alt text. Instead, it is whether the words would make sense to somebody who cannot see the picture at all.
That is the question this tool asks of every image and every alt tag on the page, and it answers in plain words rather than a pass or a fail. On a long article you get the full list plus a score, so the weakest alt tags rise to the top.
Why a Missing Alt and an Empty Alt Mean Different Things
A missing alt attribute is a fault. With nothing to read, many screen readers fall back to the file name and read out something like "IMG underscore 4031 dot jpg".
An empty alt, written alt="", is a decision instead. It tells assistive technology to skip the image, which the W3C guidance on decorative images recommends for a divider, a background shape or an icon beside a word that already says the same thing.
Therefore this checker counts the two separately. The first needs fixing, while the second usually needs nothing at all.
Why A Linked Image Matters Most
When an image is the only thing inside a link, its alt text becomes the name of that link.
Without it, the link has no name, so a screen reader announces the address or simply "link". A visitor tabbing through the page then meets a row of identical, nameless stops.
For that reason these rows are listed first. Moreover, the alt text on a linked image should describe where the link goes, not what the picture looks like.
Alt Text That Passes And Still Fails
Most validators stop at "the attribute exists". As a result, alt="DSC00412.jpg", alt="image" and alt="banner" all pass, although none of them tells a listener anything.
This checker reads the words. It spots file and camera names, single generic words, and openings such as "image of", which a screen reader already says before the text.
It also notices the same alt text repeated across three or more different images, since that is usually a theme default rather than a description.
Copies Inside Noscript
Lazy loading plugins often leave a second copy of each image inside a noscript tag for crawlers. The checker lists those copies, then keeps them out of the counts, so one picture is never judged twice.
Alt Text Length: Aim Below 125 Characters
A single short sentence tends to do the job. Many screen readers cut off, or at least become hard to follow, somewhere past 125 characters.
If an image needs more explanation, such as a chart or a diagram, put the detail in a visible caption or in the text beside it. Then keep the alt short and let it point there.
Limits of the Alt Text Checker
It reads the page as the server sends it, which is also what a crawler reads first. Consequently, images that a script adds later, and images set as CSS backgrounds, do not appear here.
CSS background images cannot carry alt text anyway. If one of them carries meaning, it belongs in an img tag instead.
Working With the Image Alt Text Checker, Start to Finish
One address in, one row per image out, with the problems listed first.
- 1
Paste the page address
Any public page works. A bare domain is fine too, because https:// is added for you.
- 2
Press check
This server reads the page once and returns every image and frame on it. The page itself is never shown here.
- 3
Start with the red rows
Linked images without alt come first, since those links have no name. Then come images with no alt at all.
- 4
Use the suggested words
Where the file name is readable, the checker turns it into a starting sentence. Edit it into a real description before you use it.
What Sets This Alt Text Checker Apart
Most checkers count attributes. This one reads what they say.
Eight verdicts, not two
Missing, linked, file name, generic, redundant, too long, repeated and decorative. Each Denwix finding comes with its reason.
Linked images first
An image that is the whole link decides that link's name, so those faults sit at the top of the list.
A suggested fix beside each image
Each problem comes with the next step, and often with a starting sentence built from the file name.
Decoration left alone
alt="" and aria-hidden are counted as decisions, not faults, because on a divider they are the right answer.
Frames checked too
An embedded video or map is named by its title attribute, so frames without one are flagged as well.
Export in one click
Copy the report or download it as CSV, then hand it to whoever edits the page.
Habits for Writing Useful Alt Text
Eight habits that turn an attribute into a description.
- Say what the picture tells the reader, not which colours it holds. Think about what the picture brings to the page. Describe the product in a product shot, and the takeaway in a chart.
- Name the destination on a linked image. If the picture is the link, the alt text is the link text. So "Read our pricing" beats "Blue arrow".
- Leave out "image of". Screen readers say "image" before the alt text anyway. Open with the main subject of the picture.
- Use alt="" for decoration. Dividers, flourishes and background shapes should be skipped, and an empty alt is how you say so.
- One sentence, under 125 characters, is enough. Past about 125 characters the detail belongs in a caption, where everybody can read it.
- Write text that is in the image. If a banner says "Summer sale, 30 per cent off", the alt text should say that too, otherwise the offer is invisible to a listener.
- Do not stuff keywords. Alt text written for search engines reads badly aloud. Besides, a natural description already carries the words that matter.
- Run the Denwix check again after every redesign. Themes and page builders reset alt text more often than people expect, so rerun the check whenever the template changes.
Six Alt Text Mistakes That Pass Validators
Each of these has an alt attribute, and each still leaves a listener guessing.
The camera file name
alt="IMG_4031" is what an upload leaves behind. It passes every validator and describes nothing.
One generic word
"Logo", "image" and "banner" name a category. Instead, say whose logo, or what the banner offers.
The same text everywhere
A gallery of twenty photos all called "Our work" gives a listener one fact twenty times.
A paragraph in the attribute
Long alt text cannot be skimmed or paused. Put the detail in a caption and keep the alt short.
An empty alt on a link
alt="" on the only thing inside a link leaves the link with no name at all.
Keywords instead of words
A list of search terms sounds like spam when it is read aloud, and it helps nobody find the page.
Alt Text Questions People Ask
What is alt text?
It is the text in an image's alt attribute. Screen readers speak it, browsers show it when the image fails, and search engines read it to understand the picture.
Should decorative images carry alt text too?
Each img tag should carry an alt attribute, even an empty one. However, a purely decorative image should have an empty one, alt="", so screen readers skip it.
Will better alt text help my images rank?
Yes. It is the main way a search engine learns what an image shows, which matters for image search. Still, write it for people first, since that also reads best to a crawler.
How many characters should alt text use?
A single sentence, best kept below 125 characters. Longer explanations belong in a visible caption.
Why does Denwix check alt but not the title attribute on images?
Alt replaces the image for people who cannot see it. Title is an optional tooltip that most screen readers ignore, so it cannot stand in for alt text.
Why does the checker flag my logo?
Usually because the alt text says only "logo". Say whose logo it is, and if it links home, say that instead, such as "Denwix home".
Why do some pictures not appear in the Denwix list?
The checker reads the page as the server sends it. Images added later by a script, or set as CSS backgrounds, are not in that markup.
What are the noscript copies?
Many lazy loading plugins put a second copy of each image inside noscript for crawlers. They are listed, although they are left out of the counts.
Can the Denwix checker read a page that needs a login?
No. The page has to be public, since this server reads it the way a visitor without an account would.
Does Denwix keep a copy of the page I check?
No. The address serves one read and then goes, and this server keeps no copy of the page or the report.
Tools For Checking Images
Alt text is one question about an image. These answer the others.
Lazy Loading Checker
Which images load too early, and which wait too long.
Open tool →Image Size Finder
Width, height and file weight, measured in your browser.
Open tool →Image Converter
Turn heavy images into WebP or AVIF without uploading them.
Open tool →
Ready To Check Your Images?
Paste an address and read a verdict for every image on it. This image alt text checker costs nothing, needs no login and stores nothing about the page.