Signal vs Slack

Signal explicitly says it does not sell, rent, or monetize your personal data or content. That is a strong privacy commitment compared with many ad-supported services.

Signal says it cannot access the contents of your messages or calls because they are end-to-end encrypted. In practice, this sharply limits what the company can read or disclose about your communications.

If Signal harms you, its total contractual liability is capped at $100 to the extent allowed by law, and many categories of damages are excluded. This significantly limits practical remedies.

The policy says message history stays on your devices and that server-side technical data is limited to what is necessary to operate the service. This reduces the amount of personal information retained centrally.

You must sign up with a phone number and accept verification texts or calls. That creates an identity link many privacy-conscious users may prefer to avoid.

Disputes must be brought in specified California courts under California law. This can make it harder or costlier for non-California or international users to pursue claims.

Signal can update its terms and privacy policy, with continued use treated as acceptance, and it may suspend or terminate access at any time for any reason. Users have limited leverage if terms worsen or access is cut off.

Signal states that you own the information you submit through the service. Notably, the terms do not describe a broad content license letting Signal exploit user content.

If you use contact discovery, Signal may hash address-book data and send it to its servers to find other users. This is optional and privacy-protective by design, but still involves sharing derived contact data.

Signal says encrypted information and metadata may be transferred to the United States and other countries where it or its providers operate. Users outside those countries may face different legal protections.

Signal is not a substitute for emergency services. Relying on it in a crisis could be dangerous because it does not connect to police, fire, hospitals, or similar services.

Users can manage personal information and enable extra protections like a Registration Lock PIN in the app settings. This is a useful transparency and account-security feature.

If you use Slack through work, your employer or workspace owner controls messages, files, settings, exports, and many privacy choices. In practice, your organization—not you—usually decides retention, access, and deletion of workspace content.

Workspace owners and admins may access, modify, or restrict your information, including profile details and workspace activity logs. Users should not assume workplace Slack activity is private from their organization.

Slack collects extensive non-content data including logs, device identifiers, approximate location, cookies, imported contacts, integration data, and audio/video metadata. This creates a detailed record of how you use the service even outside message content itself.

Slack says it does not 'sell' personal data under CCPA definitions, but it may share identifiers and internet activity with third-party advertisers for targeted ads off Slack. That means some personal data can still support advertising ecosystems.

Slack states it does not sell personal information as defined by the CCPA and says it would provide a right to opt out before doing so. This is a meaningful privacy commitment, even though ad-related sharing still occurs.

Users may have rights to access, correct, delete, restrict, object, and for Californians opt out of certain sharing. Slack also recognizes Global Privacy Control for cookie-based sharing opt-outs.

When integrations are enabled, Slack may receive and share data with those providers, which operate under their own privacy policies. Slack expressly does not guarantee those providers fully disclose permissions.

Slack keeps customer data according to employer instructions, but may retain other personal data as long as necessary for support, audits, legal compliance, disputes, and business interests. This does not give users a firm deletion timeline for all personal data.

Slack clearly says data may be transferred internationally, including to the U.S., and identifies Standard Contractual Clauses and APEC certifications as safeguards. This is helpful transparency for cross-border data handling.

Slack can change its privacy policy over time and asks users to review it, with extra notice only for material changes to privacy rights. Continued use may effectively mean accepting updated terms unless you deactivate your account.

Slack links to supporting materials like subprocessors, security practices, data request resources, transparency reporting, and data export guidance. That makes it easier for users and organizations to evaluate operational privacy practices.