Social preview monitoring for content & web teams

Find the metadata issues behind Slack previews.

Check the titles, descriptions and images your pages serve for link previews. Use the report to investigate missing or unexpected Slack cards, then follow up after publishing changes.

Start with a free scan. No account or credit card. Then choose weekly follow-ups by email or Slack for up to 10 report pages.

Paste a page, a domain, or up to 10 URLs, one per line.

See what the report shows

Quick diagnosis

Slack preview missing or not updating? Start here.

  1. Check the message and preferences

    Use the full public URL, including https://, in a message with one link. Check that link previews are enabled. Slack may suppress a preview when the same URL was shared in the conversation within the past hour.

  2. Separate page access from image access

    Check the metadata in the published HTML, then open the exact og:image URL without signing in. A working page can still point to a protected, deleted or expired image.

  3. Retest after the source is fixed

    Run another scan to verify what your server returns. Then check a new Slack message. ShareScan does not clear Slack’s cache or replace cards in existing messages; connected apps can also control their own unfurls.

A clear place to start

See the issue. Find the page. Follow up.

  1. Check the sourceInspect titles, descriptions and images in the metadata your pages serve.
  2. Review the findingsOpen affected pages and use the issue details to decide what needs fixing.
  3. Check again after changesRun another scan after a fix, or set up recurring checks for the pages that matter.

Previews are based on fetched metadata. Slack, LinkedIn and X may show a different or cached card.

ShareScan / Preview reportActual product view
A ShareScan report showing a metadata score, checked pages and findings from a scan of sharescan.io.
A real scan of sharescan.io, captured 8 October 2026. A dated snapshot of three pages, not a live status.

From finding to fix

What to check and how to follow up.

Check 01

How Slack unfurl issues show up

Slack previews can display old titles, missing images, generic fallback cards, or no preview at all when metadata is unstable.

Why it happens

  • Inconsistent canonical and Open Graph values during rollout.
  • Image URLs blocked by auth, region, or security policies.
  • URL rewrites that produce different metadata by environment.
  • The link points to a private page, omits the scheme, or has already been cached in the channel.

What to do next

  • Align canonical, OG, and Twitter metadata on the final public URL.
  • Serve share images publicly with stable cache headers.
  • Scan production URLs directly after deploy.
Check 02

Why Slack previews differ from LinkedIn or X

One URL can render differently across channels because fetch and caching behavior is platform-specific.

Why it happens

  • Different crawler user agents and tag precedence rules.
  • Different cache refresh timing and retry behavior.
  • Partial deploy windows where metadata and assets are out of sync.

What to do next

  • Use one deterministic metadata source per URL.
  • Run a scan before sharing high-impact links in Slack.
  • Track issue-level diffs across releases to catch drift.
Check 03

Slack-led workflow for monitoring setup

Preview incidents move faster when setup instructions and alerts land in the Slack workspace that owns the page.

Why it happens

  • Preview failures are often discovered late by campaign stakeholders.
  • No consistent handoff between content, marketing, and engineering teams after metadata changes.

What to do next

  • Scan your first URL free and review the report before sharing the link widely.
  • Choose a follow-up channel and complete setup for the pages you want to monitor.
  • Use alerts to catch broken preview images after deploys, CMS edits, and template changes.

When your team needs broader coverage

Bring recurring checks into your publishing workflow.

Create a workspace and verify your domain to schedule scans, manage URLs and connect CMS or GitHub Actions triggers. The Free workspace plan covers up to 100 pages.

Create free workspaceCompare monitoring plans

Before you start

A few useful details.

Why does Slack not show a link preview?

Slack may skip unfurling when the page lacks preview metadata, is private, blocks crawlers, omits the URL scheme, has too many links in one message, or was recently shared and cached in the same conversation.

Why does Slack show the wrong image?

The image may be blocked, cached, or replaced by fallback metadata. Validate image URL accessibility and tag values on the final URL.

Why did previews regress right after deploy?

Metadata templates, redirects, or image assets likely changed between releases. Compare scan diffs to isolate exactly what shifted.

Can I send scan output directly to Slack?

Yes. Connect Slack from the report to receive setup instructions and continue configuring monitoring for that URL.

How do I keep Slack previews stable over time?

Start with a scan, continue setup in Slack, and use monitoring to catch preview regressions after deploys, CMS edits, or image changes.

Explore a related check

More ways to keep previews in view.

Social Preview Testing

Test preview behavior across Slack, LinkedIn, X, and Open Graph metadata.

Link Preview Checker

Run cross-platform preview checks before sharing links.

Open Graph Monitoring & Alerts

Track Open Graph regressions and get preview alerts in Slack.