Slackbot

social-preview Slackbot

Slack's link expansion web crawler bot

About this crawler

Slackbot is a web crawler identified by the regular-expression pattern Slackbot in the User-Agent request header. It is categorised as social-preview. Use the regex above to detect, log, allow, or block Slackbot traffic in your web server, CDN edge rules, or robots.txt.

Block-rate · top 25k sites

0.13%
latest snapshot
2026-06-04
matched key: Slackbot
2026-05-012026-06-040.17%

Technical details

Name
Slackbot
Pattern
Slackbot
Tags
social-preview
Reference
https://api.slack.com/robots
Added
2016/11/03
rDNS suffixes
.slack-edge.com, .slack.com
Instances
3 known sample(s)

rDNS verification (FCrDNS)

Verify a request is genuinely Slackbot with forward-confirmed reverse DNS: the client IP's PTR record must end in one of the suffixes below and a forward A/AAAA lookup of that hostname must return the same IP. UA strings alone are spoofable; FCrDNS is not.

Sample User-Agent strings

Slackbot-LinkExpanding (+https://api.slack.com/robots)
Slackbot-LinkExpanding 1.0 (+https://api.slack.com/robots)
Slackbot 1.0 (+https://api.slack.com/robots)

Block this crawler

robots.txt — disallow Slackbot:

User-agent: Slackbot Disallow: /

Apache .htaccess — return 403:

RewriteEngine On RewriteCond %{HTTP_USER_AGENT} Slackbot [NC] RewriteRule .* - [F,L]

Nginx — return 403 inside a server block:

if ($http_user_agent ~* "Slackbot") { return 403; }
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