What Open Graph tags actually do
When a URL is pasted into a social network or chat app, that platform's crawler fetches your page and reads four meta tags from the og: namespace: og:title, og:description, og:image and og:url. X (Twitter) uses its parallel twitter:card tags, falling back to Open Graph when they are missing.
If the tags are absent, the platform guesses — usually badly: no image, a truncated title, or a description scraped from random page text. If the tags are wrong, the wrong card shows, and the platforms cache aggressively: fixing the tags today does not fix cards already cached.
The image problem
The single most common failure: og:image missing, relative instead of absolute, smaller than 200×200 px, or pointing at a URL behind auth. Any of these renders no image at all.
The cache problem
Facebook and LinkedIn cache share data for days. Fix tags first, then use each platform's debugger to force a re-scrape — otherwise you're testing stale data.
One check, all tags
A good checker validates every tag at once: presence, sizes, absolute URLs, image dimensions and twitter:card fallbacks.
How to check your Open Graph tags
Option A — automated (recommended). Paste your URL into the free page profiler. Alongside the full technical SEO report you get the complete Open Graph and Twitter Card picture: which tags exist, whether og:image resolves and meets size minimums, and whether twitter:card has sane fallbacks.
Option B — view-source. Open your page, view source, and search for og:. You should find at least title, description, image and url inside the <head>. Remember: tags rendered client-side by JavaScript are invisible to most platform crawlers — they must be in the raw HTML response.
Option C — platform debuggers. After fixing, run Facebook's Sharing Debugger and LinkedIn's Post Inspector to refresh their caches and confirm the new card. Each platform caches independently; clearing one does not clear the others.
Image rules of thumb
1200×630 px, absolute URL, under ~8 MB, publicly reachable, PNG or JPEG. That passes every major platform's requirements with margin.
Title and description lengths
Cards truncate around 55–65 characters of title and ~110–160 of description depending on platform. Put the important words first.
Per-page tags
One shared set of OG tags across a whole site means every shared article shows the homepage card. Generate them per template — most CMSs do this with one plugin or one meta partial.
Five Open Graph mistakes that kill click-through
1. Missing og:image entirely. Posts without images get dramatically less engagement on every platform. This is the highest-value fix on this list.
2. Relative image URLs. <meta property="og:image" content="/img/cover.jpg"> works in a browser but renders nothing in a share preview. Always absolute.
3. JavaScript-injected tags. Platform crawlers mostly do not execute JS. If your SPA sets OG tags at runtime, shares show nothing. Render tags server-side.
4. Identical tags everywhere. Template-level defaults leaking onto articles make every share look identical — and users stop clicking.
5. Forgetting twitter:card. Without twitter:card (usually summary_large_image), X falls back to a small plain summary. One line fixes it.
Everything above is free. Doing it for every URL by hand is what Pro is for.
Everything in this guide is free, and it stays free: the Page Profile profiler in the browser and as a CLI, with its full Open Graph and Twitter Card picture, its Redirect chain trace, All checks, history tracking, JSON output and a Terminal report with score and grade. Paste a URL and you get every og: tag, whether og:image resolves, and whether twitter:card has sane fallbacks — no account, no expiry, no limit on how many pages you check.
Pro adds exactly three things on top of that, and changes nothing else. What it cannot do is the repetition, and this guide points at it itself: mistakes four and five are per page and per template, and Facebook, LinkedIn and X each cache independently — so what you have to prove is not "does this one page look right" but "does every page look right, and does it look different than it did yesterday". batch mode reads a whole list of URLs from a file and profiles them in one run, compare mode from the command line diffs two pages from the terminal so you can see exactly which og: tags a fix moved instead of reading two reports and hoping, and a client-ready html report hands the client the same evidence you just produced instead of a screenshot of your terminal.
| What you get | Free | Page Profile Pro — $19/year |
|---|---|---|
| Open Graph and twitter:card checks per URL | yes, per URL | same, on a whole list of URLs |
| Redirect chain trace + All checks + Terminal report with score and grade | yes | yes |
| history tracking and JSON output | yes | yes |
| How many pages per run | one at a time | batch mode — a file of URLs in one run |
| Seeing which og: tags a fix moved | two reports, read side by side | compare mode from the command line — the diff, line by line |
| What you send the client | terminal text you paste yourself | a client-ready html report |
The license covers up to 3 of your own machines. Buying it changes nothing about the free tier above — the Open Graph and twitter:card checks, the Redirect chain trace, All checks, history tracking, JSON output and the Terminal report with score and grade stay free and stay MIT. Pro only adds the last three rows.
Buy Page Profile Pro — $19/year Buy Page Profile Pro Lifetime — $39 once
Frequently asked questions
Is this checker free?
Yes. The page profiler runs in your browser, needs no account, and covers Open Graph, Twitter Cards plus the rest of your page's technical health in the same report.
Why does my fix not show up yet?
Platform caches. Use Facebook's Sharing Debugger and LinkedIn's Post Inspector to force a re-scrape after deploying changes. Until then you are looking at old cached data.
Do OG tags affect SEO rankings?
Not directly — Google reads title/meta description, not og: tags, for ranking. But share previews drive clicks and traffic, and a broken preview quietly kills that channel.
What about WhatsApp, Slack, iMessage?
All read Open Graph tags. The same rules apply: absolute image URLs, server-rendered tags, sensible dimensions.
Danish version?
There is a Danish technical SEO guide and a fully Danish profiler at /da/page-profile.
Can I automate this in CI?
Yes — the companion Python CLI outputs JSON for any URL, so a pipeline can fail a build when og:image goes missing. See the technical SEO check guide.
Tools and guides
Technical SEO check for your website → also see the meta tag checker
Free meta tag checker for any URL: title, meta description, robots, canonical, viewport and social tags.
Test Your Zip File, Before You Hit Publish
A practical checklist: how to open and verify your release zip before users see it.
Check your page's meta tags
How to check a webpage's meta tags: title, description, Open Graph, Twitter cards and structured data — free…
Dansk version: Open Graph-tjekker: se dit link før du deler det