Free meta tag and on-page SEO checker
Paste the HTML of any page and get a score, a pass/warn/fail list and a preview of how it looks in Google and when shared. It runs in your browser, nothing is uploaded.
Why paste instead of a URL? Browsers cannot read another website’s HTML because of CORS, so use View source, copy, paste. Scripts in the pasted HTML are never run.
Google result preview
Shared link preview
Loading the image sends a request to the image’s own server.
How to use it
- Open the page you want to check, press Ctrl+U (Windows) or Cmd+Option+U (Mac) to View source, select all and copy.
- Paste it into the box below and click Check HTML. Or click Load example to see a page with typical problems.
- Work through the failures first, then the warnings. Re-paste the HTML after each change to see the score move.
What this checker looks at, and why
These are the tags that decide how a page appears in search results and when a link is shared. Each is quick to fix and easy to forget.
Title and meta description
The title is the blue headline in Google and the strongest on-page signal for what a page is about. The meta description does not affect ranking directly, but Google often uses it as the snippet, so a clear sentence with a reason to click improves the click rate. Too long and it is cut off; too short and the space is wasted.
Canonical and robots
A canonical link tells Google which URL is the master copy when the same page can be reached several ways (with and without www, with tracking parameters, with a trailing slash). A noindex robots tag does the opposite and removes the page from results, so the checker flags it as a failure.
Headings and image alt text
Use one h1 that says what the page is, then h2 for sections and h3 inside those, without skipping levels. Alt text describes an image for screen reader users and for search engines. Purely decorative images should have an empty alt="" so they are skipped.
Open Graph and Twitter cards
When someone pastes your link into Slack, WhatsApp, LinkedIn or X, those apps read og:title, og:description and og:image to build the preview card. Without them you get a bare URL or a random picture. Use an image around 1200 by 630 pixels and a full https address.
Viewport and language
The viewport tag makes the page scale properly on a phone, which Google needs for mobile-first indexing. The lang attribute on the html element declares the page language.
This tool checks the HTML you paste, as it was served. Content added later by JavaScript is not included.
Questions people ask
Why can’t I just enter a URL?
A web page cannot fetch another site’s HTML in the browser, because the browser blocks it (CORS). The only ways around that are a server that downloads the page for you, which would mean your URL leaves the browser, or pasting the source, which keeps everything local.
What is a good title and meta description length?
Aim for a title of roughly 30 to 60 characters and a description of 70 to 160. Google measures pixels, not characters, so these are safe ranges rather than hard limits.
Does a perfect score mean I will rank?
No. Meta tags make a page eligible and clickable; they do not replace useful content and links. Treat the score as a checklist of basics that are cheap to fix.
Why does it say my page is not indexable?
The page contains a robots meta tag with noindex. That tells Google to leave it out of search results. It is correct for thank-you pages and staging sites, and a costly mistake on pages you want found.
Want a landing page that scores well from day one? We build fast, clean pages with the SEO basics, mobile layout and sharing cards already done.
See landing pages