Does Slack train on your data?
Slack does not build generative AI models on your messages, but it does train predictive models on them by default. Opting out means emailing support.
"If you want to exclude your Customer Data from helping train Slack global models, you can opt out."
- 24 Aug 2026
- 5 Oct 2026
- All accounts
- global
- Fetched from the company
- 5F075D57…0E76
How we read it: Two separate promises, and only one is a no. Slack states plainly that it does not develop generative AI models using Customer Data — a real protection, better than most here. But the same page says predictive models for features like emoji and channel recommendations "analyse Customer Data (e.g. messages, content and files) submitted to Slack", and those are on unless you act. What makes this D rather than C is the exit: not a toggle, but an email from an org or workspace owner to Customer Experience quoting the workspace URL and a set subject line — so an ordinary member cannot opt themselves out at all. None of this is in the privacy policy; it is published only here.
opt out, opt-out, object to, settings, toggle, turn off, disable, by default
What the document does offer
- "If you want to exclude your Customer Data from helping train Slack global models, you can opt out."
- the route: "please have your Org or Workspace Owners or Primary Owner contact our Customer Experience team at feedback@slack.com with your Workspace/Org URL and the subject line 'Slack Global model opt-out request'"
- what opting out preserves: "you will still enjoy all of the benefits of our globally trained ML models without contributing to the underlying models"
- "Slack will not use Customer Data to train generative AI models unless Customer provides affirmative opt-in consent" — a separate and stronger promise, covering generative models only
Why none of it applies: Two promises doing different work. Generative models are opt-in and that is a real protection. Predictive models are opt-out, and the exit is an email from an Org or Workspace Owner quoting a set subject line — so an ordinary member of somebody else's workspace cannot exercise it at all. That is what keeps this at D rather than C: the control exists, is documented precisely, and is out of reach of most of the people it governs.
What each plan can refuse
The same questions, asked of every plan we could identify. Every cell comes from a quoted clause or a documented search - see the evidence above.
- Contact support
- Not stated
- 55 / 100
- Not stated
- Unknown
How to opt out of Slack AI training
Plan by plan, from what Slack's own policy says about refusing. Where it publishes the steps, they're listed here with the limits they carry. Where there's nothing to switch off, or nothing graded, this says so instead of inventing a menu path.
All accounts
Yes, but not self-serve: Slack makes you contact support.
- Ask a Workspace Owner, Org Owner or the Primary Owner to email feedback@slack.com.
- Include the Workspace or Org URL and the subject line "Slack Global model opt-out request".
Owners only; a member can't do this for themselves. Slack says an opted-out workspace keeps the benefit of its global models.
What this policy has done since we started watching
7 changes detected since 1 Jan 2023. Each one is a diff between two archived copies, and each links to the passage that moved.
- Touched opt-outs and sub-processors. Not yet reviewed by a human.
- Touched opt-outs and sub-processors.
- Touched opt-outs and sub-processors.
- Touched opt-outs and sub-processors.
- Touched sub-processors. Not yet reviewed by a human.
- Touched sub-processors. Not yet reviewed by a human.
- Touched opt-outs, retention, sub-processors and plan tiers.
Vendor response
We wrote to Slack on 21 Aug 2026, quoting the clauses above and inviting a correction. Nothing has come back. That's published because a company declining to comment on its own policy is something a reader should know, and because the invitation should be on the record whether or not it's taken up. Any reply goes here, word for word.
Report a wrong clause