Slack scores 4/5 for encryption, 3/5 for privacy, and 3/5 for track record. Overall safety score: 4/5.

What are the privacy concerns with Slack?

Slack security review covering enterprise encryption, workspace privacy, and employer data access.

Has Slack been hacked before?

See our detailed analysis of Slack's past security incidents and track record at The Opt-Out Project.

Is Slack Safe? Security Review

Name: Is Slack Safe? Security Review
Item: Slack
Rating: 4
Author: The Opt-Out Project

Category: Messaging Company: Salesforce, Inc. Reviewed February 10, 2026

4/5

Overall Safety Score

★ ★ ★ ★ ★

Verdict: Slack is secure for workplace use with solid enterprise features. However, users should understand that employers can access all messages and files, including DMs, with the right plan. It is not a private messaging tool.

Slack is a workplace communication platform owned by Salesforce, used by millions of organizations for team messaging, file sharing, and collaboration. It offers enterprise-grade security but is not designed for privacy from your employer.

Security Ratings Breakdown

Category	Score	Rating
Encryption	4/5
Privacy	3/5
Track Record	3/5

Security Features

Enterprise Key Management (customer-controlled encryption keys)
Two-factor authentication
SOC 2 Type II compliance
SAML-based SSO integration
Data Loss Prevention integrations
Encryption at rest and in transit

Privacy Concerns

Workspace administrators can export all messages, including DMs (on paid plans)
Messages are not end-to-end encrypted
Salesforce integration expands potential data sharing
Retention policies controlled by employer, not user
Third-party app integrations can access message content

Past Security Incidents

2022 breach via compromised employee token exposed private GitHub repositories
2015 database breach exposed user profile information
2023 reports of AI training data concerns related to customer data (Slack updated policy after backlash)