Call Blocker review

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Call Blocker is an open-source Android application for blocking unwanted calls, spam, and telemarketing. It suits individuals and small teams that want direct control over which numbers or number prefixes are blocked, rather than a service that identifies callers or relies on shared spam reports. The app maintains a history of blocked calls, supports dual-SIM configurations, and uses Android’s native CallScreeningService integration.

Privacy and offline operation are its clearest strengths. Call Blocker requires no internet connection and sends no data to external servers, making it suitable for users who prefer local call management. Backup and restore add practical continuity, while optional AES-256-GCM encryption protects backup files. The app is distributed under the GPLv3 license, which also makes its open-source model a meaningful part of its appeal for privacy-focused Android users.

Its focused approach also defines its limits. Call Blocker handles manually specified numbers and prefixes, but it does not provide verified caller ID, community-report features, or robocall detection. That makes it a good fit for blocking known nuisance numbers and maintaining a private block list, but a weaker choice for users who want automatic identification of unfamiliar callers or broader spam intelligence. The published product details show a free application rather than a set of paid tiers, and support is community-based. Choose Call Blocker for offline, manual blocking on Android; look elsewhere if caller intelligence, automated detection, or broader platform coverage is essential.

Call Blocker pros and cons

• Where it wins
  • Blocks specific numbers and number prefixes
  • Works offline without external data transmission
  • Supports dual SIM and encrypted backups
• Where it doesn't
  • Available only on Android
  • No verified caller ID or robocall detection
  • Community support may not suit users seeking direct assistance

Call Blocker fact sheet, pricing and score →

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Last updated 7 Oct 2026 · How we research and update