Slack privacy posture

https://slack.com/trust/privacy/privacy-policy

On Slack, your employer is the customer and you are not. The organisation that owns the workspace controls the messages in it, decides how long they are kept, and on paid plans can export private channels and direct messages without notifying you.

12policy revisions
Last reviewed: Aug 5, 2026

Privacy Posture

Who controls your messages
Your employer, not you
Slack splits data in two. “Customer Data” is the messages, files and content in a workspace; the “Customer” -- the organisation that signed the agreement, typically your employer -- is its controller, and Slack is only the processor. Everything else Slack collects about you (“Other Information”) has Slack as controller. In practice that means data requests about your messages go to your employer, not to Slack.
Slack Privacy Policy — Identifying the Data Controller and Processor
Admin access to private channels and DMs
Available to workspace owners on paid plans
Since the 20 April 2018 policy revision, owners of paid Plus and Enterprise workspaces can export the contents of private channels and direct messages without notifying the people in them. The previous Compliance Export tool required that users be told. The redline for that change is on this page.
Slack Privacy Policy archive — 20 April 2018
AI and ML training
Used for global models by default; opt-out is owner-only
Slack states that Customer Data helps train the “global ML models” behind features like search ranking and autocomplete, and that a workspace can be excluded on request. Generative AI is treated separately: Slack says it will not use Customer Data to train generative models “unless Customer provides affirmative opt-in consent”, and that AI in Slack calls third-party LLMs. The opt-out is not available to individual users -- see the actions below.
Slack Privacy Principles — Search, Learning and Artificial Intelligence
Where the AI commitment lives
Outside the privacy policy
Slack's privacy policy does not mention artificial intelligence, machine learning or model training at all -- the words do not appear in the document. The commitments sit in a separate privacy principles page, which is not covered by Slack's dated policy archive and so has no public version history. A change there leaves no trail the way a policy change does.
Slack Privacy Policy (full text, checked for AI terms)
Retention
Set by your employer, not by Slack
Slack retains Customer Data “in accordance with a Customer's instructions” and as required by law. Other Information is kept “for as long as necessary” for the purposes in the policy. There is no fixed retention period you can rely on as a user; the answer depends on your workspace's configuration.
Slack Privacy Policy — Data Retention
Governing entity
Ireland outside the US and Canada; the US within them
Slack Technologies Limited, based in Dublin, is the controller of Other Information for workspaces established outside the US and Canada. Slack Technologies, LLC, based in San Francisco, is the controller for workspaces inside them. Personal data may be transferred to the United States under Standard Contractual Clauses.
Slack Privacy Policy — Identifying the Data Controller and Processor
Minimum age
16
Slack does not allow use of its services by anyone under 16, to the extent prohibited by applicable law.
Slack Privacy Policy — Age Limitations

What should I do?

Concrete steps, and who is actually able to take them.

  1. Get your workspace excluded from Slack's global ML training

    Only an Org Owner, Workspace Owner or Primary Owner can do this. If you are not one, you have to ask.

    • Have an Owner email feedback@slack.com from their Slack-registered address.
    • Use the exact subject line Slack asks for: “Slack Global model opt-out request”.
    • Include the Workspace or Org URL the request covers.
    • Slack replies once the opt-out has been applied — keep that confirmation, as there is no setting in the admin console that shows the current state.

    Opting out excludes your workspace's data from models trained across customers. Slack says you keep the benefit of the globally trained models either way.

    Slack Privacy Principles — opt-out instructions
  2. Find out who can read your direct messages

    Any member can check who the owners are; only they can tell you the export settings.

    • Sign in and open slack.com/account/team — the address Slack's own policy gives for finding your workspace owners and administrators.
    • Ask them which plan the workspace is on — private-channel and DM export is a paid Plus and Enterprise capability.
    • Ask whether Compliance Export or Discovery API access is switched on, and whether members are notified when an export runs.

    Slack's policy tells you to direct these questions to your employer: it is the controller of Customer Data, so Slack will not answer them for you.

    Slack Privacy Policy — Your Rights
  3. Exercise a data-subject right (access, deletion, correction)

    Anyone, but the request usually has to go through your employer.

    • For messages and files, contact the workspace owner — Slack is the processor and will refer the request back to the Customer.
    • For everything Slack controls in its own right, email its Data Protection Officer at dpo@slack.com.
    • State the workspace URL and the specific right you are exercising; EEA, UK and Brazil residents have statutory rights Slack names explicitly.
    Slack Privacy Policy — Your Rights and Data Protection Officer
  4. Limit tracking on Slack's websites

    Anyone.

    • Slack's cookie controls are documented in its Cookie Policy rather than the privacy policy.
    • Cookie choices cover the marketing websites and parts of the product; they do not affect what your workspace retains about your messages.
    Slack Cookie Policy

Privacy policy change history

Slack publishes every historical version of its privacy policy at a stable, dated URL. The version history below is built from those documents, so each redline compares two texts Slack published itself. The most recent comparison runs from the last archived version to the copy captured directly from the live policy page.

13 versions tracked · Jul 22, 2014Apr 22, 2026 · 12 recorded changes

Nov 17, 2016 → Apr 20, 2018+183 171 lines

The revision that let paid workspace owners export private channels and direct messages without telling the people in them. Slack cited GDPR preparation; labour advocates read it as a material weakening of employee privacy.

@@ -1,184 +1,196 @@
Effective: November 17, 2016
Introduction
Our privacy policy will help you understand what information we collect at Slack, how Slack uses it, and what choices you have.
When we talk about “Slack,” “we,” “our,” or “us” in this policy, we are referring to Slack Technologies, Inc., the company which provides the Services. When we talk about the “Services” in this policy, we are referring to our online workplace productivity tools and platform. Our Services are currently available for use via a web browser or applications specific to your desktop or mobile device, as further described in our
Effective: April 20, 2018
This Privacy Policy describes how Slack collects, uses and discloses information, and what choices you have with respect to the information.
Updates in this version of the Privacy Policy reflect changes in data protection law. In addition, we have worked to make the Privacy Policy clearer and more understandable by:
organizing it into the sections listed in the Table of Contents below,
providing a series of examples that help illustrate how the policies may be implemented by Slack and
defining and capitalizing a few terms that are used more than once for simplicity and brevity.
When we refer to “
Slack
”, we mean the Slack entity that acts as the controller or processor of your information, as explained in more detail in the “Identifying the Data Controller and Processor” section below.
Table of Contents:
Applicability of this Privacy Policy
Information We Collect and Receive
How We Use Information
Data Retention
How We Share and Disclose Information
Security
Age Limitations
Changes to this Privacy Policy
International Data Transfers: Privacy Shield and Contractual Terms
Data Protection Officer
Identifying the Data Controller and Processor
Your Rights
Data Protection Authority
Contacting Slack
Applicability Of This Privacy Policy
This Privacy Policy applies to Slack’s online workplace productivity tools and platform, including the associated Slack mobile and desktop applications (collectively, the “
Services
”), Slack.com and other Slack websites (collectively, the “
Websites
”) and other interactions (e.g., customer service inquiries, user conferences, etc.) you may have with Slack. If you do not agree with the terms, do not access or use the Services, Websites or any other aspect of Slack’s business.
This Privacy Policy does not apply to any third party applications or software that integrate with the Services through the Slack platform (“
Third Party Services
”), or any other third party products, services or businesses. In addition, a separate agreement governs delivery, access and use of the Services (the “
Customer Agreement
”), including the processing of any messages, files or other content submitted through Services accounts (collectively, “
Customer Data
”). The organization (e.g., your employer or another entity or person) that entered into the Customer Agreement (“
Customer
”) controls their instance of the Services (their “
Workspace
”) and any associated Customer Data. If you have any questions about specific Workspace settings and privacy practices, please contact the Customer whose Workspace you use. If you have an account, you can check
http://slack.com/account/team
for contact information of your Workspace owner(s) and administrator(s). If you have received an invitation to join a Workspace but have not yet created an account, you should request assistance from the Customer that sent the invitation.
Information We Collect And Receive
Slack may collect and receive Customer Data and other information and data (“
Other Information
”) in a variety of ways:
Customer Data
. Customers or individuals granted access to a Workspace by a Customer (“
Authorized Users
”) routinely submit Customer Data to Slack when using the Services.
Other Information.
Slack also collects, generates and/or receives Other Information:
Workspace and Account Information. To create or update a Workspace account, you or your Customer (e.g., your employer) supply Slack with an email address, phone number, password, domain and/or similar account details. For details on Workspace creation,
click here
. In addition, Customers that purchase a paid version of the Services provide Slack (or its payment processors) with billing details such as credit card information, banking information and/or a billing address.
.
click here
.
.
.
Data Request Policy
.
.
.
Contacting Slack
Slack Technologies, Inc.
500 Howard Street
United States

Showing 60 of 354 changed lines. Both source documents are linked below in full.

Source: version of Nov 17, 2016Source: version of Apr 20, 2018

Dec 6, 2022 → Apr 22, 2026+16 10 linesarchive → live capture
@@ -1,4 +1,4 @@
Effective: December 6, 2022
Effective: July 5, 2023
This Privacy Policy describes how Slack collects, uses, and discloses information associated with an identified or identifiable individual (referred to in this Privacy Policy as
@@ -165,8 +165,8 @@
Third-Party service providers and partners.
We may engage third-party companies or individuals as service providers or business partners to process Information and support our business. These third parties may, for example, provide virtual computing and storage services, assist Slack with verifying Owners and Customers, or we may share business information to develop strategic partnerships with Third-Party service providers to support our common customers. In this respect, depending on the Third-Party service provided, Slack may share your Information. Additional information about the subprocessors we use to support delivery of our Services is set forth at
.

Showing 3 of 26 changed lines. Both source documents are linked below in full.

Source: version of Dec 6, 2022Source: version of Apr 22, 2026

Jun 14, 2021 → Dec 6, 2022+164 106 lines
@@ -1,14 +1,16 @@
Effective: June 14, 2021
This Privacy Policy describes how Slack collects, uses and discloses information and what choices you have with respect to the information.
Effective: December 6, 2022
When we refer to “

Showing 3 of 270 changed lines. Both source documents are linked below in full.

Source: version of Jun 14, 2021Source: version of Dec 6, 2022

Oct 5, 2020 → Jun 14, 2021+56 48 lines
@@ -1,5 +1,5 @@
Effective: October 5, 2020
This Privacy Policy describes how Slack collects, uses and discloses information, and what choices you have with respect to the information.
Effective: June 14, 2021
When we refer to “

Showing 3 of 104 changed lines. Both source documents are linked below in full.

Source: version of Oct 5, 2020Source: version of Jun 14, 2021

Aug 21, 2020 → Oct 5, 2020+5 3 lines
@@ -1,4 +1,4 @@
Effective: August 21, 2020
Effective: October 5, 2020
This Privacy Policy describes how Slack collects, uses and discloses information, and what choices you have with respect to the information.
@@ -60,7 +60,7 @@
. We receive information from you, your Customer and other third-parties that helps us approximate your location. We may, for example, use a business address submitted by your employer, or an IP address received from your browser or device to determine approximate location. Slack may also collect location information from devices in accordance with the consent process provided by your device.
Cookie Information. Slack uses cookies and similar technologies in our Websites and Services to help us collect Other Information. The Websites and Services may also include cookies and similar tracking technologies of third parties, which may collect Other Information about you via the Websites and Services and across other websites and online services. For more details about how we use these technologies, and your opt-out opportunities and other options, please see our
Cookie Policy

Showing 3 of 8 changed lines. Both source documents are linked below in full.

Source: version of Aug 21, 2020Source: version of Oct 5, 2020

Jan 1, 2020 → Aug 21, 2020+10 12 lines
@@ -1,4 +1,4 @@
Effective: January 1, 2020
Effective: August 21, 2020
This Privacy Policy describes how Slack collects, uses and discloses information, and what choices you have with respect to the information.
@@ -12,7 +12,7 @@
Changes to this Privacy Policy
International Data Transfers: Privacy Shield and Contractual Terms
Data Protection Officer

Showing 3 of 22 changed lines. Both source documents are linked below in full.

Source: version of Jan 1, 2020Source: version of Aug 21, 2020

Apr 20, 2018 → Jan 1, 2020+59 41 lines
@@ -1,9 +1,5 @@
Effective: April 20, 2018
Effective: January 1, 2020
This Privacy Policy describes how Slack collects, uses and discloses information, and what choices you have with respect to the information.
Updates in this version of the Privacy Policy reflect changes in data protection law. In addition, we have worked to make the Privacy Policy clearer and more understandable by:
When we refer to “

Showing 3 of 100 changed lines. Both source documents are linked below in full.

Source: version of Apr 20, 2018Source: version of Jan 1, 2020

Nov 3, 2015 → Nov 17, 2016+163 136 lines
@@ -1,157 +1,184 @@
Effective: November 3rd, 2015
Our Privacy Principles
If you read nothing else, please read this:
.

Showing 3 of 299 changed lines. Both source documents are linked below in full.

Source: version of Nov 3, 2015Source: version of Nov 17, 2016

May 1, 2015 → Nov 3, 2015+40 35 lines
@@ -1,4 +1,4 @@
Effective: May 1, 2015
Effective: November 3rd, 2015
Our Privacy Principles
@@ -16,20 +16,20 @@
Slack Privacy Policy
Updated: May 1, 2015
This privacy policy is here to help you understand what information we collect at Slack, how we use it, and what choices you have. When we talk about Slack in this policy, we are talking about Slack Technologies, Inc., the company, Slack, the downloadable application, and the Slack website at

Showing 3 of 75 changed lines. Both source documents are linked below in full.

Source: version of May 1, 2015Source: version of Nov 3, 2015

Mar 11, 2015 → May 1, 2015+43 22 lines
@@ -1,9 +1,13 @@
Effective: March 11, 2015
Effective: May 1, 2015
Our Privacy Principles
Slack is the custodian of data on behalf of the teams that use Slack. We don’t own team communication data. Teams own their data. They like it that way and so do we.
At Slack we believe that more transparency is better than less. We try to make our product easy to use, with settings and options that are easy to find and understand. This is good for privacy, good for the product, and good for Slack customers and users.
We think that having more information be easily accessible and searchable wherever you go, whatever device you have, is better than having less. So this is how we built Slack. Teams can select their own data retention policies (depending on their level of service) but our defaults show our bias. Administrators and owners can change these settings but we want you to know where we stand.

Showing 3 of 65 changed lines. Both source documents are linked below in full.

Source: version of Mar 11, 2015Source: version of May 1, 2015

Jan 1, 2015 → Mar 11, 2015+10 8 lines
@@ -1,4 +1,4 @@
Effective: January 1, 2015
Effective: March 11, 2015
Our Privacy Principles
@@ -12,7 +12,7 @@
Slack Privacy Policy
Effective: January 1, 2015
This privacy policy is here to help you understand what information we collect at Slack, how we use it, and what choices you have. When we talk about Slack in this policy, we are talking about Slack Technologies, Inc., the company, Slack, the downloadable application, and the Slack website at

Showing 3 of 18 changed lines. Both source documents are linked below in full.

Source: version of Jan 1, 2015Source: version of Mar 11, 2015

Jul 22, 2014 → Jan 1, 2015+119 77 lines
@@ -1,87 +1,129 @@
Effective: July 22, 2014
Our Policy:
Welcome to the web site: https://slack.com (the “Site”) of Slack Technologies, Inc. (“Slack Technologies”, “we”, “us” and/or “our”). This Site is operated by Slack Technologies and has been created to provide information about our company and our service, Slack, which includes real-time communication, messaging, archiving and search services and related systems, technologies, and mobile applications (together with the Site, the “Service(s)”) to our Service users and visitors (“you”, “your”). This Privacy Policy sets forth Slack Technologies’s policy with respect to information including personally identifiable data (“Personal Data”) and other information that is collected from visitors to the Site and users of the Services.
.

Showing 3 of 196 changed lines. Both source documents are linked below in full.

Source: version of Jul 22, 2014Source: version of Jan 1, 2015

How this page is made

Compiled from the platform's own published documents. Every claim on this page links to the primary source it came from, and the change history is built by comparing versions the platform published itself. Checked and maintained by hand; no part of this page is generated from those sources automatically.

Maintained by Redact Holdings, Inc., which operates PrivacyWire. Last checked Aug 5, 2026. Found something wrong? Tell us.