Enter your page address to see how your link looks on Google, X, LinkedIn, Facebook, Slack, WhatsApp and Discord. The checker lists missing or weak tags and writes a fixed set you can copy. For localhost and staging pages, use the free bookmarklet: online preview tools cannot reach them.
Title tag: Pass.
39 characters.
Meta description: Pass.
120 characters.
og:title: Pass.
Present.
og:description: Pass.
Present.
og:image: Pass.
Present.
Image URL: Pass.
Absolute https URL.
Image size: Checking.
Loading the image to read its size.
og:url: Pass.
Present.
twitter:card: Warning.
Missing. Without it X may show a small card or none.
Canonical link: Warning.
Missing. Tells search engines which URL is the main one.
Favicon link: Pass.
Present.
html lang: Pass.
lang="en".
Close approximations of each app. Apps change their layouts often and cache old previews.
Acme
https://acme.example/
Acme: invoices your clients pay on time
Acme sends clear invoices, chases late payments for you and shows what is due this week. Free for your first 10 clients.
From acme.example
Acme: invoices your clients pay on time
acme.example
acme.example
Acme: invoices your clients pay on time
Clear invoices, polite reminders and a weekly cash view.
Acme
Acme: invoices your clients pay on time
Clear invoices, polite reminders and a weekly cash view.
Acme: invoices your clients pay on time
Clear invoices, polite reminders and a weekly cash view.
acme.example
https://acme.example/
Acme
Acme: invoices your clients pay on time
Clear invoices, polite reminders and a weekly cash view.
<title>Acme: invoices your clients pay on time</title>
<meta name="description" content="Acme sends clear invoices, chases late payments for you and shows what is due this week. Free for your first 10 clients.">
<link rel="canonical" href="https://acme.example/">
<meta property="og:type" content="website">
<meta property="og:site_name" content="Acme">
<meta property="og:title" content="Acme: invoices your clients pay on time">
<meta property="og:description" content="Clear invoices, polite reminders and a weekly cash view.">
<meta property="og:url" content="https://acme.example/">
<meta property="og:image" content="https://blocksnap.site/og.png">
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:title" content="Acme: invoices your clients pay on time">
<meta name="twitter:description" content="Clear invoices, polite reminders and a weekly cash view.">
<meta name="twitter:image" content="https://blocksnap.site/og.png">Replace any example.com value with your real address. Image URLs must be absolute and on https.
Open Graph is a set of meta tags that tells apps how to show your page when someone shares the link. The tags give the title, the description, the image and the address that appear in the preview card.
Facebook made the protocol in 2010. Today LinkedIn, Slack, Discord, WhatsApp, iMessage and most chat apps read it. X reads its own twitter: tags first and falls back to the Open Graph tags.
Use a bookmarklet. Online preview tools fetch your page from their own servers, so they cannot reach localhost, a staging site behind a password or a page behind a login. The OG check bookmarklet runs in your own browser tab, reads the tags of the page you have open and sends them straight to this tool.
The tags travel in the part of the address after the # sign, which browsers never send to a server. Nothing about your unreleased page leaves your device, and you can fix the share card before the page goes live.
The bookmarklet also sees tags that JavaScript adds after the page loads. The share bots of X, LinkedIn, Slack and Facebook mostly read the HTML your server sends and do not run JavaScript. If a tag shows with the bookmarklet but not in the URL check, render that tag on the server.
| What you need to check | URL check | Bookmarklet | Paste HTML |
|---|---|---|---|
| A public page | Yes | Yes | Yes |
| localhost or a preview deploy | No | Yes | Yes |
| Staging behind a password or VPN | No | Yes | Yes |
| A page behind a login | No | Yes | Yes |
| Tags added by JavaScript | No | Yes | Only if you copy them |
| Passes through a server | Ours, head tags only | No | No |
| Effort | Type the address | One click | Copy and paste the source |
As of October 2026 · Source: How this tool works
Every page needs a title tag, a meta description, og:title, og:description, og:image, og:url and twitter:card. With these seven, every major app can show a full preview with a large image.
Add a canonical link so search engines know the main address, and a favicon link so Google can show your icon. og:image must be an absolute https URL, and 1200 x 630 pixels is the safe size.
You can add og:type, og:site_name and the og:image width and height too. They are optional, but the width and height help some apps show the image on the first share.
| Platform | Title shown | Description shown |
|---|---|---|
| Google search | About 60 (about 600 px wide) | About 155 to 160 |
| X large card | About 70, over the image | Usually not shown |
| About 70, up to 2 lines | Usually not shown | |
| About 60 to 90, up to 2 lines | About 1 line, often hidden | |
| Slack | Full title, 1 to 2 lines | About 3 lines |
As of October 2026 · Source: BlockSnap tests of each app. Limits depend on screen width and change often.
Each app reads the same tags but draws its own card, with its own crop, font and text limits. Each app also caches the preview the first time someone shares the link, so a change to your tags does not show at once.
To refresh the cache, paste the URL into the Facebook Sharing Debugger and choose Scrape Again, or into the LinkedIn Post Inspector. X no longer has a card validator page, so post the link in a draft or add a query string such as ?v=2 to get a fresh preview.
Slack and Discord cache unfurls for a while too. A new query string on the URL forces a new fetch in most apps.
BlockSnap builds your SaaS landing page from proven sections and publishes it with the title, description, Open Graph and X tags already set.
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