What is Slackbot?
Slack's robots fetch metadata to unfurl links posted in Slack, proxy and cache posted images, and make other requests such as API calls and outgoing webhooks.
Fetches a page when someone shares its link, to draw the preview card. Blocking it breaks your previews in that app.
Slack says it does not honor robots.txt because it acts on behalf of a human and does not follow links. Unfurl results are cached for about 30 minutes.
Slackbot user agent
Slack documents these user agents for Slackbot. Version numbers in it change over time, so match on the name, not the whole string.
Slackbot-LinkExpanding 1.0 (+https://api.slack.com/robots)
Slack-ImgProxy 0.19 (+https://api.slack.com/robots)
Slackbot 1.0 (+https://api.slack.com/robots)Should you block Slackbot?
Allow it. Blocking it breaks the preview card when someone shares your link.
How to block Slackbot in robots.txt
Slack says Slackbot does not follow robots.txt, so a robots.txt rule won’t stop it. Block it at your server or firewall by user agent, and by IP if Slack publishes its ranges.
Slack says to contact it if you want your site blocked from Slack embeds or want changes to how they display.
How to verify a request is really Slackbot
Anyone can send any user agent, so the string alone proves nothing.
Slack publishes no IP ranges or DNS names for Slackbot that we could find, so there is no reliable way to tell a real Slackbot from a scraper using its user agent.
See when Slackbot reads your site
Bots don’t run JavaScript analytics, so a script tag never sees them. invisit records crawler reads on the server instead, through its server SDK or a Cloudflare Worker, and shows which bots read which pages, next to your visitors.
Checked against Slack’s own documentation on . Something changed? Write to help@invisit.dev.