Fill in the page title, description, URL and share image, and the tool writes the tags that belong in the page's <head>: the <title>, meta description, link rel="canonical", an optional robots tag, theme-color, the Open Graph tags (og:title, og:description, og:url, og:image with width, height and alt, og:site_name, og:type, og:locale), the X card tags and a JSON-LD block (WebPage, Article or Product). Below the code you see approximate share cards for Facebook, LinkedIn, X, Slack and a Google result, and a list of checks against the limits the platforms document. Already have a page? Paste its source into "Start from an existing page's HTML" and the fields fill in.
Nothing is fetched. The tool never downloads your page or your image URL; to see a real picture in the previews, pick the image file from your device. It is shown from memory and never uploaded.
The limits it checks, and where they come from
- Title: Google shortens titles by pixel width, about 600 px on desktop, which is roughly 50 to 60 characters of ordinary text. Over 60 characters you get a warning. X's card markup allows 70 for
twitter:title. - Description: Google shows roughly 150 to 160 characters on desktop (about 920 px) and fewer on phones. X allows 200. Under 50 characters is flagged as a note: a card with almost nothing to say gets fewer clicks.
- Image: Meta recommends at least 1200 x 630 px for sharp cards and 600 x 315 as the minimum; below that, Facebook shows a small thumbnail. LinkedIn asks for 1200 x 627 at 1.91:1. X crops large cards to 2:1 and small summary cards to a square, so an image far from the card's ratio is noted.
- URLs must be absolute (
https://...). Crawlers do not resolve /images/card.jpg in og:image; that is one of the most common reasons a preview shows no picture. - Lengths are counted the way people read them: an emoji or a Vietnamese letter with its tone mark counts as one.
Platforms change these rules without notice, and they were checked on 14 October 2026. Treat them as guidance, then confirm with each platform's own debugger before a launch.
Why the previews are approximate
Each platform draws its own card, and each changes the design from time to time. Facebook puts the domain in capitals above the title, LinkedIn shows the title under the image, X has shown only the domain on top of large images since 2023, Slack shows the site name and a smaller picture, and Google may rewrite your title entirely. For the Google result alone, the SERP snippet preview measures the title and description in pixels with Arial. The drawings here show the important things: how the image is cropped, roughly where text is cut, and which tags each platform reads. To make a card image at exactly 1.91:1, crop it with the image crop tool using a 1200 x 630 frame, and give the site its tab icon with the favicon generator.
Using the output
Copy the tags into the <head> of the page, or download them as an HTML file. In frameworks such as Next.js, WordPress SEO plugins or Hugo themes, the same fields have their own settings; use the checks here to decide what to type. After publishing, platforms keep a cached copy of the card: Facebook's Sharing Debugger and LinkedIn's Post Inspector can force a fresh read, while X refreshes on its own after a while. The article Open Graph tags that actually work explains how each platform crops the image and the mistakes that leave a share without a picture. If a title contains characters such as & or quotes, the tool escapes them for you; to check other text by hand, use the HTML entity encoder.
