Facebook Post Preview

How to use

1. 1Choose Builder mode to fill in fields by hand, or Validate HTML mode to paste an existing page's HTML head.
2. 2In Builder mode, click Load sample to see a worked example, then edit og:title, og:description, og:image, and the other fields. The character counters turn amber as you approach Facebook's feed clipping limits.
3. 3In Validate HTML mode, paste a full HTML document or just the head. The tool parses every og: and fb: meta tag with DOMParser (no scripts run, nothing is fetched from your source).
4. 4Watch the desktop feed and mobile feed previews on the right update as you type. The card layout switches automatically between the large image card and the small thumbnail card based on the og:image size and aspect ratio.
5. 5Read the validation checklist for missing required tags, length warnings, image size and aspect-ratio warnings, https warnings, and locale format issues. Click Copy on the meta tag block to paste the result into your page head.

About this tool

Facebook Post Preview renders the same link share card Facebook produces when someone posts your URL, locally in your browser, so you can confirm what users will see before you publish. Facebook reads Open Graph (og:) meta tags from the page being shared and uses them to build the feed link card. Since Facebook removed the visual preview from its public Sharing Debugger, knowing exactly how a card will render means either reading the spec and trusting your own tags, or pasting the same URL into a private test post on Facebook. This tool runs the same logic offline. There are two modes. Builder mode lets you fill in og:url, og:title, og:description, og:image, og:site_name, og:type, og:locale, and the optional fb:app_id, and watch live desktop and mobile feed previews update as you type. Validate mode parses an HTML head you paste with the browser's DOMParser (scripts and remote resources inside the pasted HTML never run or fetch) and extracts every og: and fb: tag automatically. Both modes run the same validation checks: required fields (og:title, og:image), recommended fields (og:description, og:url, og:site_name, og:type), length warnings tuned to Facebook's feed card clipping (around 88 characters for the title and 200 characters for the description), https warnings for og:image, locale format checks (en_US, pt_BR, fr_FR), and aspect-ratio checks against the recommended 1200 x 630 (1.91:1) image size. When the og:image URL loads, the tool reads its intrinsic width and height with a hidden Image element and warns when the image is smaller than the 200 x 200 hard minimum, smaller than the 1200 x 630 large-card threshold, or far from the 1.91:1 aspect ratio (which is when Facebook falls back to the small left-thumbnail card layout instead of the large image card). The desktop preview switches between the large image card and the small thumbnail card based on the same heuristics Facebook uses, and the mobile preview shows the iOS and Android Facebook app rendering. A copy-ready meta tag block at the bottom is always synced with the current fields, so you can paste a clean set of og: tags into your page head in one click. Everything happens in the browser; URLs, HTML, and field values are never uploaded to a server.

Free to use. Works in your browser. No signup, no login.