SlackImageProxy is a bot in the link preview bots category, operated by Slack.
This robot is used to fetch and cache images posted into Slack channels.
Link preview bots fetch a page when someone shares its URL in a chat app or social network, to build the preview card. Blocking them breaks your link previews, so keep them allowed but leave them out of analytics and ad requests.
SlackImageProxy identifies itself with this user agent string:
Slack-ImgProxy (+https://api.slack.com/robots)Anyone can copy a user agent string. Transfon Security also checks where each request comes from, so a request that claims to be a known crawler but comes from the wrong network is treated as a fake, not as the real crawler.
We have not confirmed whether SlackImageProxy follows robots.txt. Add a rule, then check your logs to see that it stopped. robots.txt is a plain text file at the root of your domain, such as https://example.com/robots.txt.
User-agent: Slack-ImgProxy Disallow: /
User-agent: Slack-ImgProxy Disallow: /private/ Disallow: /search
User-agent: Slack-ImgProxy Allow: /blog/ Disallow: /
User-agent: Slack-ImgProxy Allow: / User-agent: * Disallow: /
User-agent: Slack-ImgProxy group, SlackImageProxy ignores your User-agent: * rules, so repeat any that should still apply.Slack-ImgProxy from SlackImageProxy's user agent; check Slack's own documentation if it publishes a different robots.txt name.Treat robots.txt as a statement of your policy, and enforce it where requests arrive.
SlackImageProxy fetches pages when your links are shared or syndicated. Keep it allowed so previews and feeds work, but leave it out of page views and ad requests.
Transfon Security for publishersWhen ads or posts are shared, SlackImageProxy fetches the landing page. Those hits are not clicks, so keep them out of campaign reports.
Transfon Security for advertisersProduct links shared in chats and feeds are fetched by SlackImageProxy. Keep it allowed so previews show the right image and price.
Transfon Security for e-commerceAllow SlackImageProxy on public pages so shared links preview well, and keep it off the app.
Transfon Security for SaaS and APIsrobots.txt is a request, not an enforcement. Transfon Security shows SlackImageProxy by name in the Top Bots report, so you can see how often it visits and which pages it reads. Block or allow it with a User Agent rule, or slow it down with a rate limit decision rule.
Transfon Security
SlackImageProxy is a bot in the link preview bots category, operated by Slack. This robot is used to fetch and cache images posted into Slack channels.
We have not confirmed whether SlackImageProxy follows robots.txt. Add a robots.txt rule, then check your logs to see that it stopped, and block it by user agent if it did not.
Add "User-agent: Slack-ImgProxy" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "Slack-ImgProxy" at your WAF. In Transfon Security that is one User Agent block rule.
No. robots.txt is voluntary, so SlackImageProxy may not follow it, and anyone can send SlackImageProxy's user agent, so a fake SlackImageProxy ignores your rule. Enforce the rule where requests arrive, at your WAF, and check the source network.
Link preview bots fetch a page when someone shares its URL in a chat app or social network, to build the preview card. Blocking them breaks your link previews, so keep them allowed but leave them out of analytics and ad requests.
Transfon Security identifies every bot in this directory in your traffic reports, flags fake search crawlers, and lets you allow, block or rate limit each bot.
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