CrawlCheck

AI crawlers · Social link previews

Slackbot-LinkExpanding

Slackbot-LinkExpanding is the link-preview fetcher run by Slack: Slack unfurl. Its operator publishes no IP ranges or DNS names for it, so a request carrying this name cannot be verified. Treat the name in a log line as a claim.

User-agent tokenSlackbot-LinkExpanding
OperatorSlack
What it doesSlack unfurl
Kindlink-preview fetcher
Can a request be verified?No — user agent string only
In a CrawlCheck scanRead from robots.txt; reported, never scored

Allow or block it in robots.txt

User-agent: Slackbot-LinkExpanding
Disallow: /
User-agent: Slackbot-LinkExpanding
Allow: /

Add a group that names it: "User-agent: Slackbot-LinkExpanding" followed by "Disallow: /". A crawler follows only the most specific group that names it, so once a group names Slackbot-LinkExpanding, rules under "User-agent: *" no longer apply to it; repeat in that group any Disallow lines you still want.

What blocking it changes

No. It renders the preview card when someone shares your URL. Blocking it breaks those previews, not AI answers.

See what Slackbot-LinkExpanding and every other named agent receive from your own site: run a free scan. The full catalogue is on AI crawlers and as JSON at /ai-crawlers.json.

Questions about Slackbot-LinkExpanding

QHow do I block Slackbot-LinkExpanding in robots.txt?
Add a group that names it: "User-agent: Slackbot-LinkExpanding" followed by "Disallow: /". A crawler follows only the most specific group that names it, so once a group names Slackbot-LinkExpanding, rules under "User-agent: *" no longer apply to it; repeat in that group any Disallow lines you still want.
QHow can I tell if a request from Slackbot-LinkExpanding is real?
Its operator publishes no IP ranges or DNS names for it, so a request carrying this name cannot be verified. Treat the name in a log line as a claim.
QDoes blocking Slackbot-LinkExpanding affect whether my site appears in AI answers?
No. It renders the preview card when someone shares your URL. Blocking it breaks those previews, not AI answers.
QDoes CrawlCheck test my site as Slackbot-LinkExpanding?
Not as a request. CrawlCheck reads the rules your robots.txt sets for Slackbot-LinkExpanding and reports them. Rules for it are reported and never scored, because refusing it is a policy choice.