Crawl any website and audit its SEO, AI readiness, speed, security and accessibility, with an AI summary of what to fix first.
Users
8,000
0 in 30 days
Rating
4.7 / 5
unchanged in 30 days
Ratings
14
0 in 30 days
Store rank
#11K
#9,591 among extensions
Version
2.0
updated 19 Sep 2026
Users
monthly, 2 years
Latest, 15 Oct 2026:8,000 usersMove the mouse over the chart for any month
Ratings count
monthly, 2 years
Latest, 15 Oct 2026:14 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About SEO Checker
SEO Checker is an easy to use browser extension that audits your website's SEO, page speed, security, accessibility and AI readability. It crawls thousands of pages, scores each one against 87 checks and tells you in plain language what to fix and how.
New in version 2.0:
- AI audit summary: after every crawl the dashboard shows a short assessment of your site, the issues to fix first in order of impact, and the quick wins. No API key or account needed.
- Accessibility checks: page language, heading order, iframe titles, form labels, descriptive link text and page zoom.
- AI readability: is your content visible without JavaScript, does it carry structured data, are links plain HTML, is there an llms.txt file, and are AI crawlers allowed in.
- International SEO: hreflang validity, self-reference, x-default and reciprocity.
- XML sitemap: validity, orphan pages that only the sitemap links to, and indexable pages missing from it.
- More checks: favicon, Open Graph tags, Twitter card, broken in-page anchor links, server response time, and the Content-Security-Policy, Referrer-Policy and Permissions-Policy headers.
- Compare two audits to see which checks improved or regressed, page by page.
- Per-URL report with a Google search snippet preview, an internal link graph, and a search filter in every results table.
- Report history: your last 20 audits stay in the extension so you can reopen them any time.
- Generate an llms.txt or a sitemap.xml from the crawled pages.
- White-label PDF reports with your own name and logo, crawling behind basic authentication, URL list mode, and crawl settings remembered per domain.
What SEO Checker checks:
- Page titles and meta descriptions: too long, too short, missing or duplicated.
- Headings: one well-sized, unique H1 on every page.
- URLs: short, lowercase, without parameters, symbols, underscores or deep nesting.
- Content: duplicate or thin pages, image alt text, mobile scaling, canonical tags.
- Broken links and resources, 404 handling and server errors.
- Redirects: temporary and permanent redirects, chains and loops.
- Robots.txt presence and sitemap locations.
- Code validity of your HTML, CSS and JavaScript.
- Speed: compression, minification, inline code, render-blocking scripts, caching and cache lifetimes, duplicate resources, server response time.
- Security: HTTPS, HSTS, MIME types, content sniffing, clickjacking and XSS protection, hidden server information, modern security headers.
Export any audit to Excel or CSV, save the whole crawl to a file and load it again later, or print the audit report as a PDF. SEO Checker runs in your browser; only a compact summary of the audit results is sent to our server to produce the AI summary.
Information on updates to the extension can be found at https://seochecker.io/news