Free Alt Text Checker
Paste any page URL and get an instant alt text report: a 0-100 score, a letter grade, and a fix suggestion for every image. No signup, no limits, no fluff.
What the checker looks for
Missing alt attributes
Images with no alt attribute at all. Screen readers announce nothing useful, and search engines get zero context. This is the most serious issue we flag.
Filename alt text
Alt text like "IMG_4823.jpg" or "hero-banner-v2". It technically exists, but it describes nothing and can read as spammy to search engines.
Redundant phrases
Alt text starting with "image of" or "photo of". Screen readers already announce images, so these words waste the listener's time.
Overly long descriptions
Alt text longer than 125 characters. Many screen readers pause or truncate around that length, so concise beats exhaustive.
Empty alt (decorative)
An empty alt attribute is correct for decorative images, but it is worth a quick check: meaningful images sometimes ship with alt="" by accident.
Good alt text
Descriptive, concise alt text under 125 characters that skips filler phrases. For writing tips, see our alt text SEO best practices guide.
Oversized image files
We also measure image file sizes and flag anything over 100KB. Heavy images slow down your page, hurt Core Web Vitals, and cost you rankings. The report totals your page image weight and estimates your compression savings.
Frequently asked questions
What is alt text and why does it matter?
Alt text (alternative text) is a written description attached to an image in HTML. Screen readers read it aloud for visually impaired visitors, browsers show it when an image fails to load, and search engines use it to understand what the image shows. Good alt text improves accessibility, supports WCAG and ADA compliance, and helps your images rank in search.
Does an empty alt attribute fail the check?
No. An empty alt attribute (alt="") is valid HTML and is the correct choice for purely decorative images, since it tells screen readers to skip the image. The checker flags empty alt text as "verify decorative" with a small score deduction, so you can confirm each one really is decorative and not a meaningful image that lost its description.
How is the alt text score calculated?
Every page starts at 100. We deduct points based on the share of images in each problem category, weighted by severity: images with no alt attribute at all cost the most, followed by filename-style alt text, redundant phrases like "image of", overly long descriptions above 125 characters, and finally empty alt attributes, which cost the least. A page where every image has descriptive alt text scores 100 and earns an A.
Does it check image file sizes too?
Yes. Alongside the alt text audit, the checker measures the file size of up to 25 images on the page. Anything over 100KB is flagged as heavy and anything over 300KB as huge, since oversized images slow down your page and hurt Core Web Vitals. The report shows your total page image weight and estimates how much you could save with compression (typically about 65% smaller files). File size does not affect your alt text score.
How do I fix missing alt text in WordPress?
You can edit each image manually in the WordPress media library by filling in the "Alternative Text" field, but that gets slow fast on sites with hundreds of images. The Altomatic plugin generates accurate, SEO-friendly alt text automatically with AI in 50+ languages, and can process your entire media library in bulk while also compressing your images.
Want the full picture? Read alt text SEO best practices and how to bulk add alt text in WordPress.
Stop writing alt text by hand
Altomatic writes accurate, keyword-aware alt text for your whole WordPress media library in 50+ languages, and compresses every image while it's at it.