Image Alt Attribute Checker
Image Alt Attribute Checker counts img-tag-looking substrings and reports as missing any tag without alt="nonempty" or alt='nonempty'. Consequently it also flags alt="", even though an empty alt is correct for many decorative images, and it misses unquoted forms or semantic context. It does not parse the DOM, inspect rendered images, judge alternative-text quality, associate captions, detect CSS backgrounds, or perform a full accessibility audit.
Runs locally — files stay on your deviceDoes every image need nonempty alt text?
No. Decorative images commonly need an explicit empty alt attribute.
Alt decisions depend on image purpose
Informative images need equivalent concise text; decorative images usually use alt="" so assistive technology can ignore them.
How it works
A regex collects img tags, then another requires a quoted alt value containing at least one character.
Key concepts
Empty can be correct
Purpose, not visual appearance alone, determines the alternative.
Regex is not accessibility semantics
Roles, context, captions, and rendered state are absent.
When to use it
- Spot obvious missing alt attributes in simple pasted markup.
- Create a candidate review list.
- Count img-tag strings quickly.
When not to use it
- Do not treat every flagged empty alt as failure.
- Do not use it to judge wording quality.
- Do not call it WCAG conformance testing.
Worked examples
Informative image
- Input
<img src="chart" alt="Sales rose 12%">- Expected output
Not flagged
Quality is not assessed.
Decorative
- Input
<img src="line" alt="">- Expected output
Flagged
This is a false positive under many correct designs.
Missing
- Input
<img src="team.jpg">- Expected output
Flagged
No alt attribute matches.
Common mistakes
Filling decorative alt
Noise can harm screen-reader use. Correction: Keep explicit empty alt when appropriate.
Keyword stuffing
Nonempty passes regardless of usefulness. Correction: Describe equivalent purpose.
Claiming compliance
Only a regex condition is checked. Correction: Perform contextual manual and automated testing.
Best practices
- Classify each image's function.
- Write concise equivalent text for informative images.
- Use alt="" for genuinely decorative images and test accessibility.
Related operations and differences
External Link Extractor
Choose External Link Extractor when you need to extract links pointing away from a hostname.; use Image Alt Attribute Checker specifically for alt check.
Internal Link Extractor
Choose Internal Link Extractor when you need to extract relative and same-host links.; use Image Alt Attribute Checker specifically for alt check.
Canonical Tag Generator
Choose Canonical Tag Generator when you need to generate a canonical link element from a URL.; use Image Alt Attribute Checker specifically for alt check.
FAQ Schema Generator
Choose FAQ Schema Generator when you need to generate FAQPage JSON-LD from question-answer blocks.; use Image Alt Attribute Checker specifically for alt check.
Heading Structure Checker
Choose Heading Structure Checker when you need to list H1–H6 elements from pasted HTML.; use Image Alt Attribute Checker specifically for alt check.
Hreflang Tag Generator
Choose Hreflang Tag Generator when you need to generate language alternate tags from URL lines.; use Image Alt Attribute Checker specifically for alt check.
Limitations and privacy
- Regex scan of pasted img tags.
- Flags valid empty alt; no DOM, context, quality, role, caption, CSS-image, rendered-state, WCAG, or screen-reader assessment.
The pasted text or URL is processed locally in this browser and is not fetched or submitted by the tool.
Frequently asked questions
Why is alt="" flagged?
The checker requires at least one character, even though empty alt can be correct.
Does it judge alt quality?
No.
Are background images checked?
No.
Is this a full accessibility audit?
No.