Meta Tag Validator. Check Your SEO Tags Against Best Practices
Paste a page's HTML and get a strict, letter-graded verdict on every meta tag that matters, title and description length, canonical, robots, viewport, charset, and Open Graph / Twitter completeness, each rule marked pass, warn or fail with an exact fix.
What is the meta tag validator?
The Meta Tag Validator checks a pasted page's head against an explicit SEO rulebook, grading title and description length, canonical, robots, viewport, charset and Open Graph/Twitter completeness as pass, warn or fail with exact fixes and an A–F grade. Free and browser-based via native DOMParser, so staging pages and unreleased copy stay private.
The GigAI Meta Tag Validator checks a page's `<head>` against an explicit rulebook of SEO best practices and returns a graded conformance report rather than a vague 'looks fine'. Paste your full page source (or just the `<head>`), and the browser's own parser extracts every relevant tag and runs it through categorised rules: Foundations (a single `<title>`, one meta description, a canonical link, a responsive viewport, a declared charset, and a robots directive that isn't accidentally blocking the page), Length (title and description measured against the 50–60 and 150–160 character sweet spots), Social (Open Graph and Twitter Card completeness: the specific properties each network needs to render a rich card), and Conflicts (duplicate titles or descriptions, and a canonical that fights a noindex). Each rule is marked pass, warn or fail with a plain-English reason and the exact markup to fix it, and the whole page earns an A–F grade so you can tell at a glance whether it's ship-ready. Because the whole thing runs locally with the native DOMParser, nothing you paste (staging URLs, gated pages, unreleased copy) is ever uploaded, stored or logged.
- Difficulty:
- Easy
- Typical time:
- ~30s
- Processing:
- 100% browser processing
Last updated
How to use the meta tag validator
- 1
Copy your page's HTML
View source on the page (Ctrl+U / Cmd+Option+U) and copy it, or grab just the <head> block. Works on live, staging, login-gated and unreleased pages alike.
- 2
Paste it into the validator
Drop the markup into the box. The browser parses it instantly and runs every best-practice rule locally. Nothing is uploaded.
- 3
Read the graded checklist
Scan the A–F grade, then work down the pass/warn/fail rules grouped into Foundations, Length, Social and Conflicts.
- 4
Apply the inline fixes and re-check
Copy the corrected markup shown next to each failing rule into your template, paste the updated head back in, and confirm the grade improves.
What Meta Tag Validator includes
Rulebook-driven, not vibes
Every check maps to a named SEO best-practice rule with a pass, warn or fail state, so you get a defensible verdict on each tag, not a single ambiguous score.
A–F conformance grade
The page earns a letter grade from the weighted results, so you can tell at a glance whether the head is ship-ready or still failing essentials.
Exact length validation
Title and description are measured against the 50–60 and 150–160 character sweet spots, flagging copy that's too short to earn clicks or long enough to be truncated.
Open Graph & Twitter completeness
Checks for the specific og:* and twitter:* properties each network needs (og:title, og:image, twitter:card) so shared links render a rich card instead of a plain box.
Conflict & duplicate detection
Catches two <title> tags, duplicate meta descriptions, and the classic canonical-vs-noindex contradiction that quietly keeps pages out of the index.
Copy-paste fix for every failure
Each warn or fail row ships the exact markup to add or change. The fix is right next to the problem, so you can patch the head without leaving the page.
Why use our meta tag validator
Know if a page is really ship-ready
A letter grade plus per-rule pass/fail turns 'the SEO tags are probably fine' into a concrete list of what passes and what still needs fixing before you deploy.
Catch the silent index killers
A stray noindex, a canonical pointing at the wrong URL, or a missing viewport can quietly sink a page: the validator surfaces those exact failures instead of letting them ship.
Fix it without hunting the spec
Because every failing rule includes the corrected markup, you patch the head directly instead of cross-referencing documentation for the right attribute names.
Private by design
Validation runs entirely in your browser with the native parser, so staging URLs, gated pages and unreleased copy never leave your machine.
Built for the way you work
From quick one-off fixes to daily workflows, see how people put this tool to use.
- SEO specialist
Pre-launch head audit
Validate a page's meta tags against the checklist before it goes live, so a missing canonical or an accidental noindex never reaches production.
- Frontend developer
Verify template output
Confirm the head your framework or CMS actually renders is conformant: catching the duplicate title a layout and a page component both emit.
- Agency / QA
Client site sign-off
Run each key page through the validator and hand the client a clear, graded pass/fail report instead of a subjective 'the SEO is good' claim.
- Content editor
Length compliance check
Paste a draft's rendered head to confirm the title and description sit inside the ideal character ranges before publishing.
Supported formats
Accepts HTML and <head> markup, and produces Validation report and Pass/fail checklist, all processed locally in your browser.
- HTML
- <head> markup
- Validation report
- Pass/fail checklist
Frequently asked questions
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Common problems, solved
Hit a snag? Here are quick fixes for the issues people run into most.
Can I just paste a URL to validate a live page?
No. This tool runs entirely in your browser and a static site has no server to fetch a remote page from. Open the page, view its source (Ctrl+U / Cmd+Option+U), copy the HTML, and paste it here. This also lets you validate staging, internal and login-gated pages a URL-based checker can't reach.
The validator says my meta description is missing but I set one.
It reads the rendered HTML, not your source template. If the description is injected by client-side JavaScript, view source may show the pre-render markup without it, copy the head from your browser's Elements/Inspector panel (the live DOM) instead of raw view-source.
Why is a canonical flagged when the page also has noindex?
That's a real conflict: a canonical tells engines this is the authoritative URL to index, while noindex tells them not to index it. Decide which you mean: remove the noindex to let the page rank, or drop the canonical if the page genuinely shouldn't be indexed.
My Open Graph is marked incomplete though I have some og: tags.
A rich social card needs at least og:title and og:image (ideally 1200×630). Partial Open Graph still renders a plain link on some platforms, so the validator warns until both key properties are present.
Get the most out of it
Validate the live DOM, not just view-source, if any meta tags are set by JavaScript: copy the <head> from your browser's Inspector for an accurate check.
Aim for a clean A grade on every indexable page. Treat warnings as polish and failures as blockers.
A single canonical per page consolidates ranking signals: the validator flags duplicates and self-conflicting directives.
Keep exactly one <title> and one meta description. Template layers stacking their own is the most common duplicate failure.
Add og:title and og:image to every share-worthy page so the card renders rich, then re-validate to confirm the Social group passes.
What's new
Recent updates and improvements to the meta tag validator.
Initial release. Paste HTML to validate meta tags against best practices, grouped into Foundations, Length, Social and Conflicts, with per-rule pass/warn/fail verdicts and an A–F grade.
Added the canonical-vs-noindex conflict rule and inline copy-paste fixes for every failing check.
Added an extracted-tags reference panel and refined the Open Graph / Twitter completeness rules to match how each network renders cards.
Keep exploring
Related tools
Problems we solve
From the blog
- Meta Tags Explained: A Complete Guide for 2026
- Title Tag Optimization: How to Write Titles That Rank and Get Clicked
- What Is a Canonical URL? A Plain-English Guide to Fixing Duplicate Content
- Every AI Crawler User-Agent, and Whether to Allow It
- Cloudflare Blocks AI Crawlers by Default: How to Check and Fix It
Explore categories
Compare formats
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Common tasks
Your privacy is built in
Every check runs locally in your browser using its native HTML parser. Nothing you paste is uploaded, stored or logged. Staging URLs, gated pages and unreleased copy stay on your device, and closing the tab erases them completely.
- Runs in your browser
- No uploads
- Nothing stored
Ready to try the meta tag validator?
Free, private and instant. Meta Tag Validator runs right in your browser.