DOFIW HTML ACCESSIBILITY TOOLS
Alt Attribute Checker
Paste HTML to identify missing, empty, generic, filename-based, duplicated, or conflicting image alternatives—and understand what each result means.
Paste or try an image sample
Paste a fragment or complete document. The tool reads markup only; it does not load or upload image files.
Review image purpose
Detected image elements
- Run the checker to list images.
Findings and improvements
- No analysis yetINFO
Paste HTML or load an example, then select Check alt attributes.
Errors identify missing alternatives or interactive images without a name. Warnings flag text that may be redundant, generic, hidden, conflicting, or too dependent on context.
INPUTS AND OUTPUTS
What the checker analyzes
Input
HTML containing img, image inputs, or linked image-map areas. No actual image file is required.
Output
An image inventory, purpose classification, source line, errors, contextual warnings, explanations, and a copyable report.
The checker evaluates the markup it can prove. It does not invent replacement text because a useful alternative depends on why the image appears in that exact context.
PRACTICAL EXAMPLES
Match the alternative to the purpose
Describe the information or function the image contributes—not every visual detail. Decorative images should normally use an empty alt="" so assistive technology can ignore them.
RESULT EXPLANATIONS
Why the findings matter
Missing alt attribute
A browser may expose the filename or provide no useful substitute. Add an appropriate alternative, including an empty one when the image is truly decorative.
Generic or filename text
“Image” or “banner.jpg” does not communicate the image’s purpose. Write text that replaces its relevant meaning.
Empty alt in a link
An image-only link needs a name for the destination or action. Empty alt is safe only when the surrounding interactive element already has another meaningful name.
Conflicting semantics
Non-empty alt combined with presentation roles or aria-hidden suggests that author intent and exposed behavior disagree.
USE CASES
Where this review adds value
- Audit images inside WordPress posts, cards, galleries, and navigation.
- Review product thumbnails, charts, logos, icons, and image buttons.
- Check migrated markup for filenames mistakenly copied into alt text.
- Find linked images that become unnamed when their alt is empty.
- Create an actionable report for writers and developers.
LIMITATIONS
The image still needs human judgment
- The tool does not view the image, so it cannot determine whether the written alternative is accurate.
- It cannot decide with certainty whether an image is informative, functional, decorative, complex, or redundant.
- External CSS and generated content are not applied, and SVG naming needs separate inspection.
- A length warning is a review prompt, not a WCAG character limit.
- Passing this check does not establish complete WCAG or legal compliance.
PRIVACY
Your markup and images stay private
All analysis runs locally in your browser. The tool does not load image URLs, upload files, store pasted HTML, or call an API. Clipboard access occurs only when you choose to copy the report.
FREQUENTLY ASKED QUESTIONS
Questions about image alternatives
Does every image need descriptive alt text?
Every HTML image needs an alt decision, but decorative images normally need an empty alt attribute rather than a description.
How long should alt text be?
There is no universal WCAG character maximum. Keep it concise enough for the purpose and move lengthy explanations for complex images into nearby content.
Should alt text begin with “image of”?
Usually no, because assistive technology already identifies an image. The phrase can be useful when the medium itself matters, such as a painting or historical photograph.
Can a caption replace alt text?
Not automatically. A caption is available to everyone and may add context, while alt text substitutes for the image. Avoid unnecessary duplication and decide based on purpose.
What should a linked image describe?
Name the link’s destination or action rather than merely describing its appearance. For example, “DOFIW home” is more useful than “green logo.”
Does the tool inspect the actual image?
No. It analyzes only pasted HTML and never requests the image URL, which keeps processing local and avoids guessing from pixels.
This tool is an educational testing aid and does not guarantee WCAG conformance or legal compliance. Use the W3C alt decision tree for contextual decisions.