Image Alt Tag Checker – Audit Alt Text in 3 Easy Steps
Image Alt Tag Checker
Paste HTML into this image alt tag checker to instantly audit image alt attributes for SEO and ADA Accessibility compliance.
| Status | Image Source (src) | Alt Text | Issue / Suggestion |
|---|
Use this free image alt tag checker to audit every image in a block of HTML for SEO and accessibility. Paste your page code, press Audit Images, and the tool lists each image with a PASS, WARN, INFO or FAIL status and a clear fix for missing alt attributes, file-name alt text, redundant phrases and text that is too long.
Quick answer
Every meaningful image needs an alt attribute that briefly describes what it shows, ideally under 125 characters. Purely decorative images should use an empty alt (alt=""), so screen readers skip them. Avoid alt text like "IMG_2045.jpg" or "picture of", and never leave the alt attribute out completely.
Table of Contents
Alt text is read aloud by screen readers, shown when an image fails to load, and used by search engines to understand pictures. Missing or lazy alt text hurts all three.
This image alt tag checker parses your HTML in the browser, so you can audit a full page, a blog post or a template without uploading anything.
What the Image Alt Tag Checker Flags
| Status | Problem | Why it matters |
|---|---|---|
| FAIL | No alt attribute at all | Screen readers may read the file name, and it fails WCAG 1.1.1. |
| INFO | Empty alt (alt="") | Correct for decorative images only. Check it is not hiding useful content. |
| WARN | Redundant phrase like "picture of" or "image of" | Screen readers already announce that it is an image. |
| WARN | Alt text looks like a file name | "IMG_2045.jpg" tells users nothing about the picture. |
| WARN | Very short alt text | One or two letters rarely describe an image. |
| WARN | Longer than 125 characters | Long alt text is tiring to hear. Move details into a caption. |
| PASS | Descriptive, right length | Ready for SEO and accessibility. |
How to Use the Image Alt Tag Checker
Step 1: Paste Your HTML Source Code
Open your page, view the source or copy the HTML from your editor, and paste it into Raw HTML Source Code. Our sample has six images, from a good description to a missing alt and a file-name alt.
Step 2: Read the Audit Summary
Press Audit Images. The summary cards count total images, optimized images, warnings and missing alt attributes. The sample returns 6 images, 1 optimized, 4 warnings and 1 missing alt.
Step 3: Fix Each Issue in the Report Table
The table lists every image with its source, alt text and a suggestion. Rewrite "Picture of a barista pouring coffee" as "Barista pouring coffee", replace "IMG_2045.jpg" with a real description, add an alt to hero.png and shorten the 131-character chart description. Use Copy Report to share the audit with your team.
How to Write Good Alt Text
- Describe what the image shows and why it is on the page, in one short sentence.
- Be specific: "Cold brew coffee steeping in a glass jar" beats "coffee".
- Include a keyword only when it fits the picture naturally.
- Do not start with "image of", "photo of" or "picture of".
- For linked images, describe where the link goes.
- For charts, give the main takeaway and put the full data in nearby text or a table.
Decorative vs Informative Images
Decorative images, such as dividers, background shapes and icons next to text that already says the same thing, should use alt="". Informative images, such as product photos, diagrams and screenshots, need a description. If removing the image would lose information, it is informative.
Alt Text and SEO
Search engines use alt text, file names and surrounding text to understand images and rank them in image search. Good alt text also adds relevant words to the page in a natural way. Keyword stuffing in alt attributes can look spammy, so write for people first.
More on-page checks: the HTML Heading Tags Extractor, the On-Page SEO HTML Analyzer and the Open Graph Twitter Card Preview.
Frequently Asked Questions
How long should alt text be?
Aim for under 125 characters. Most good alt text is a short sentence of 5 to 15 words.
Should every image have alt text?
Every image needs an alt attribute. Informative images need a description, and decorative images should use an empty alt="".
Is alt text a ranking factor?
It helps Google understand images and can help them rank in image search. It also supports page relevance when written naturally.
What happens if the alt attribute is missing?
Screen readers may read the file name or skip the image, and the page fails WCAG 1.1.1 for non-text content.
Can I check a live URL?
Paste the page HTML into the tool. Open the page, view source, copy all, and paste it in.
Is my HTML uploaded?
No. The image alt tag checker parses your code locally in the browser and nothing is stored.