Meta Tag Debugger: a free Open Graph and link preview checker

Meta Tag Debugger shows how a page will look when someone shares its link on X, LinkedIn, Facebook, Slack, Discord, or iMessage. It is built for developers, marketers, and site owners who need to know why a shared link shows the wrong title, description, or image. Enter a URL or paste HTML and you get six previews side by side, a list of tag problems sorted by severity, and a corrected head block you can copy into your site.

How it works

  1. Enter a URL or paste HTML

    Public pages are fetched through a guarded, rate-limited proxy. Pasted HTML is parsed in your browser and never leaves it.

  2. Compare six previews

    Each card follows that platform's own tag order, image crop, and text truncation, so you can see where they disagree.

  3. Fix the source

    Work through errors, warnings, and notes, then copy a corrected head block built from values already on your page.

What it checks

  • Open Graph, Twitter Card, title, description, canonical, favicon, theme-color, and robots tags, plus JSON-LD syntax.
  • Missing, duplicated, mis-cased, or malformed tags, including property and name attributes used the wrong way round.
  • Your preview image: its measured size against the declared width and height, the 1200 × 630 recommendation, and the 200 pixel minimum.
  • Crawler-specific markup. Fetch as Chrome, Twitterbot, LinkedInBot, facebookexternalhit, Slackbot-LinkExpanding, Discordbot, or Googlebot to catch pages that serve bots something different.
  • Redirect chains, relative URLs with no base, and meta tags that look like they are added by JavaScript, which most crawlers never see.
  • Light and dark previews, shown as a focused card or inside an example feed or conversation.

Questions

Is Meta Tag Debugger free?
Yes. There is no account, no signup, and nothing to install. URL fetches are limited to 30 per minute per IP address so the proxy stays available for everyone.
Do you store my page or my HTML?
No. URL inspections go through a Cloudflare Worker that fetches the page and its preview images and passes them to your browser without saving them. Pasted HTML is parsed in your browser and is never uploaded.
Why does my link look different on each platform?
Each platform reads its own mix of tags and applies its own crop and fallback rules. X reads twitter: tags before Open Graph, while LinkedIn, Facebook, Slack, and Discord start from Open Graph. Seeing all six at once shows which value each one picked.
Why not use the platforms' own validators?
X retired its public Card Validator, and LinkedIn and Facebook require a login for theirs. This tool shows what each layout can read from your page now. It does not ask a platform to recrawl, so a platform may keep showing its cached card until it fetches the page again.
What size should my og:image be?
1200 × 630 pixels works across the most platforms. The audit flags images under 200 pixels on either side and declared sizes that do not match the real file.
Can it check a staging site or a page behind a login?
The proxy only fetches public http and https addresses, refuses private networks, and cannot log in. For staging or private pages, view the source and paste the HTML instead.