Is Slack Safe? Security Review
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)
How to Stay Safe Using Slack
- Assume your employer can read all Slack messages including DMs
- Enable two-factor authentication
- Don't share sensitive personal information via Slack
- Review connected third-party apps in your workspace
- Use a separate messaging app for personal conversations
Safer Alternatives
- Microsoft Teams (competitor for workplace)
- Element/Matrix (self-hosted, encrypted)
Last updated: February 10, 2026