Every image on your page is an opportunity — for accessibility, for image search, and for on-page SEO — but only if it has usable alt text. The Image Alt Text Analyzer scans pasted HTML and reports every img tag that is missing an alt attribute, carries an empty alt, or drags on far past the 125-character mark. Paste a page source and you will know in seconds which images are helping your SEO and which ones are silent gaps.
What Is Alt Text?
Alt text is the descriptive attribute attached to an image. Screen readers announce it to visually impaired users, search engines read it to understand the image, and browsers show it when an image fails to load. Good alt text describes what the image shows and why it matters in context — ideally including your target keyword when it is natural. Bad alt text is missing, empty on a meaningful image, or stuffed with keywords that have nothing to do with the picture.
This analyzer parses your HTML for every img tag and classifies each one: missing alt attribute, empty alt, overlong alt text over 125 characters, or a healthy descriptive alt. You get a per-image audit plus a coverage score for the whole page.
Why Alt Text Matters for SEO
Search engines cannot see pictures; they read alt text. Descriptive alt text is the primary signal for Google Images and helps your page rank for image-based queries, which can be a significant source of traffic. Accessibility matters too — missing alt text makes your content unusable for screen-reader users and can violate accessibility guidelines. And when an image fails to load, alt text is the only clue visitors get about what should be there.
How to Use the Image Alt Text Analyzer
- Open a page with images in your browser, right-click and choose “View Page Source”.
- Copy the HTML and paste it into the analyzer.
- Click Check Alt Text to scan every img tag.
- Review the image-by-image audit: missing, empty, overlong or good.
- Fix the flagged images in your media library, then re-check to confirm.
Key Features
- Full image audit: Lists every img tag with its src and current alt status.
- Missing-alt detection: Flags images with no alt attribute at all.
- Overlong detection: Warns on alt text longer than 125 characters.
- Coverage score: A 0-100 score for your page’s alt text health.
- AI-assisted insights: Explains what good alt text looks like in your context.
Best Practices for Alt Text
Describe the image in plain language and mention the keyword only when it is natural. Keep alt text under 125 characters so screen readers are not drowned in narration. Use an empty alt attribute (alt=””) only for purely decorative images. Never duplicate the caption verbatim as alt text, and avoid keyword stuffing — an alt tag packed with phrases reads as spam to both Google and assistive tech.
Frequently Asked Questions
How long should alt text be?
Keep it under 125 characters. Longer text gets cut off for screen-reader users and loses the point.
Should decorative images have alt text?
Give decorative images an empty alt attribute (alt=””). A missing attribute makes a screen reader announce the filename, which is worse than nothing.
Does alt text help with image search?
Yes. Google Images relies heavily on alt text to understand and rank images, so descriptive alt text can drive meaningful image-search traffic.
Can I use the same alt text for every image?
No. Each image should have unique alt text describing that specific image in its context. Duplicate alt text adds little value.
Conclusion
Alt text is a small attribute with a big footprint across accessibility and SEO. Run your pages through the Image Alt Text Analyzer, fix every missing, empty or overlong alt attribute, and turn your images into assets that serve both users and search engines.