You wrote the post, picked the URL, and scheduled the campaign. Then the preview shows last month's logo instead of your launch image. Previewing a website before sharing takes five minutes and saves a public mistake that no edit button can fully undo.
Short answer
Paste your live URL into a multi-platform preview tool like OpenGraph Check, review the card for each network you plan to use, and confirm tags in page source. Open the og:image URL directly. For Facebook, Instagram, and WhatsApp, also run the Facebook Sharing Debugger. For LinkedIn, use the Post Inspector. Only share when title, image, and description match your intent on every target platform.
Why preview before you share
Link previews are the first impression in feeds, Slack channels, and group chats. A broken card means:
- Lower click-through on organic and paid posts
- Brand trust damage from outdated or wrong images
- Wasted ad spend on campaigns with ugly cards
- Support tickets from confused readers
Platforms cache previews aggressively. What you see after clicking Share is often what stays for weeks. Preview first, post second.
What a link preview actually shows
Every major platform reads Open Graph meta tags from your HTML:
| Element | Source tag |
|---|---|
| Headline | og:title |
| Description | og:description |
| Image | og:image |
| URL | og:url |
If any tag is missing or wrong, the platform guesses. Guessing produces random crops, wrong titles, or blank cards. Read Open Graph Tags Explained for the full tag reference.
Step-by-step preview workflow
1. Use the exact URL you will share
Copy the final link including or excluding www, trailing slashes, and UTM parameters as planned. Test that exact string. Mismatch between tested URL and shared URL is a common source of wrong previews.
2. Check page source
Right-click → View Page Source. Search for og:image. Tags must appear in raw HTML, not only in browser DevTools after JavaScript runs.
3. Run a multi-platform preview scan
OpenGraph Check fetches your URL the way crawlers do and renders previews for:
- X (Twitter)
- Discord
One scan, every major network, under 30 seconds. Compare title length, image crop, and description truncation side by side.
4. Validate the image directly
Copy the og:image value and open it in a new tab. Expect HTTP 200, HTTPS, and no login wall. Broken images are the top cause of failed previews. Fix guide: How to Fix a Missing OG Image.
5. Use platform debuggers for networks you post on
| Platform | Tool | When to use |
|---|---|---|
| Facebook, Instagram, WhatsApp | Facebook Sharing Debugger | Meta campaigns, cache refresh |
| LinkedIn Post Inspector | B2B posts, company pages | |
| X | Card Validator | X-specific card issues |
Guides: Facebook Sharing Debugger, LinkedIn Post Inspector.
6. Send a private test share
Message the URL to yourself on WhatsApp or post in a private Slack channel. Real apps sometimes differ slightly from debugger output when cache is warm.
Preview tools compared
OpenGraph Check (recommended default)
- Multi-platform previews in one scan
- Shows raw detected tags
- Highlights missing fields
- No account required
- Best for pre-launch checks across networks
Facebook Sharing Debugger
- Official Meta scrape tool
- Clears Facebook, Instagram, and WhatsApp cache
- Shows scrape errors and warnings
- Required after changing tags on previously shared URLs
LinkedIn Post Inspector
- Official LinkedIn scrape
- Refreshes LinkedIn cache
- Shows last scrape timestamp
Browser extensions
Convenient for quick glances while browsing. Not reliable enough alone for campaign launches. Always confirm against page source.
Paste URL in platform compose box
Facebook and LinkedIn show a preview while drafting. Useful as a final sanity check, but cache may show stale data. Do not skip earlier validation steps.
What to look for in each preview
Title
- Readable at mobile width
- Under 60 characters to avoid truncation
- Matches campaign messaging, not just the HTML
<title>
Description
- Clear value proposition in the first line
- 80-125 characters ideal
- No duplicate of title
Image
- Correct aspect ratio (1200 × 630 px safe default)
- No critical text cropped at edges
- Brand colors and logo visible at thumbnail size
- Size guide: Open Graph Image Size Guide
URL domain
- Shows your brand domain, not a redirect or shortener unless intentional
- HTTPS padlock visible in preview chrome
Preview timing in your launch process
Build preview checks into these moments:
Before publishing content: Scan staging URL if publicly reachable, then production immediately after go-live.
Before scheduling social posts: Marketing team runs OpenGraph Check on every URL in the content calendar.
Before paid ad launch: Media buyer confirms preview in debugger plus OpenGraph Check. Broken OG on ads burns budget fast.
After site migrations: Re-scan every high-traffic URL. CMS and DNS changes break tags silently.
After image or title updates: Re-scrape platform debuggers. See Why Social Platforms Cache Link Previews.
Common preview surprises
Stale cached image
You updated the featured image but the preview shows the old one. Platforms cached the previous scrape. Force refresh in Facebook Sharing Debugger or LinkedIn Post Inspector.
Different preview per platform
LinkedIn crops taller. X may prefer square images. WhatsApp uses Meta cache. One image rarely looks identical everywhere. Design for the strictest crop and verify each platform in OpenGraph Check.
Preview works in debugger, fails in app
Rare timing or CDN issues. Wait 5 minutes, re-scrape, test in a fresh chat thread. Check Open Graph Cache Busting if problems persist.
No preview at all
Missing og:image, blocked crawlers in robots.txt, or page returns non-200 status. Start with How to Test Open Graph Tags.
Preview checklist for marketers
Copy before every major share:
- Live HTTPS URL tested (not localhost)
- Page source contains
og:title,og:description,og:image,og:url - Image opens directly in browser
- OpenGraph Check previews approved for target platforms
- Platform debugger scrape succeeded (if applicable)
- Private test share looks correct
- UTM parameters do not break tags or redirects
Preview checklist for developers
- Tags in server HTML, not client JavaScript
- Absolute HTTPS URLs for all OG values
-
og:urlmatches canonical share URL - Image at least 1200 × 630 px, under 8 MB
- No auth wall on image or page URL
- Cache purged after deploy
FAQ
Can I preview before the page is public?
The URL must be reachable by external crawlers over HTTPS. Use a staging subdomain without auth, or a hidden path not in navigation.
How long does a full preview check take?
Two to five minutes for OpenGraph Check plus one debugger. Ten minutes if you test three platforms thoroughly.
Does previewing affect analytics?
No. Preview tools fetch the page like a crawler. They do not count as social shares.
Why does my preview differ from a colleague's?
Platform cache varies by region and account. Re-scrape in official debuggers to sync.
Should I preview every blog post or only landing pages?
Every URL you actively promote. Organic posts on high-follower accounts deserve the same check as paid landing pages.
Can I preview Slack and iMessage?
OpenGraph Check covers Discord. For Slack and iMessage, send a private test link. See Slack Link Preview Not Working and iMessage Link Preview Broken if issues appear.
Do URL shorteners break previews?
Shorteners redirect to the final URL. Crawlers follow redirects, but extra hops can fail. Prefer sharing the canonical URL when possible.
Bottom line
Previewing before sharing is the cheapest quality gate in social marketing. Scan with OpenGraph Check, validate the image URL, confirm with platform debuggers, and send one private test. Five minutes of checking beats explaining a broken launch card to your boss.
