SpamBlocker

Free plan Android

What SpamBlocker is

SpamBlocker is a free Android app for filtering unwanted calls and SMS without replacing the phone’s default call or messaging app. For calls, it acts as a Caller ID app and does not need to remain active in the background after setup. Filters can use contacts and groups, STIR/SHAKEN, repeat calls, emergency calls, meeting mode, and time-based rules. SMS tools can block OTP floods, check spam databases, and train a local AI filter. The app can use downloadable databases such as the FTC Do Not Call registry and query services such as PhoneBlock; users can also report numbers to crowd-sourced databases. SpamBlocker takes over SMS notifications, so notifications in the existing SMS app should be turned off to avoid duplicate alerts. Its SMS log contains received messages, not sent ones. The project lists no plan for automatic SMS clearing, RCS support, or Android 9 and earlier. According to the README, offline features collect no data; online features allow the API server to see the IP address, TLS/TCP fingerprints, and reported number. The app is MIT-licensed, and the F-Droid listing specifies Android 10 or newer.

Who it suits

It suits Android users who want to filter calls and messages while keeping their existing default apps. Users comfortable with disabling duplicate SMS notifications and reviewing online-feature data exposure may find its controls useful.

What it does well

Filters calls without replacing the default call app.
Includes contact, time, and meeting-mode call rules.
Uses a local AI filter for SMS.
Supports downloadable and online spam databases.
Available free under the MIT License.

What to know first

Requires Android 10 or newer.
SMS log excludes sent messages.
No RCS support or automatic SMS clearing is planned.
Online features expose specified connection details to the API server.

Plans

Plan	Billed and limits	Price
SpamBlocker	Android 10+ · MIT-licensed app	Free

As github.com lists them, read 11 Oct 2026. The maker's own page has the final word.

Getting started

Visit the SpamBlocker project website on GitHub.
Use an Android device running Android 10 or newer.
Find SpamBlocker through its F-Droid distribution listing.
After setup, disable notifications from your existing SMS app to avoid duplicate alerts.

Verdict

SpamBlocker offers call and SMS filtering with several configurable rules and database options. Check its Android requirement, SMS notification behavior, and online-feature privacy details before choosing it.

Questions

How much does SpamBlocker cost?

The plan is free. There is no free trial.

Which devices does it support?

SpamBlocker supports Android. The F-Droid listing specifies Android 10 or newer.

Does it replace the default calling or SMS app?

No. It screens calls and SMS without replacing those default apps.

Is SpamBlocker open source?

The project is released under the MIT License.

What privacy information does the project provide?

The README says offline features collect no data. For online features, the API server sees the IP address, TLS/TCP fingerprints, and reported number.

Facts from SpamBlocker's own pages

Call filters: Call filters include contacts and contact groups, STIR/SHAKEN, repeated calls, emergency calls, meeting mode, and time-based rules. · github.com, 11 Oct 2026
Call handling: For calls, the app works as a Caller ID app and does not need to keep running in the background after setup. · github.com, 11 Oct 2026
Distribution: F-Droid lists version 5.18, added October 3, 2026, for Android 10 or newer and four Android CPU architectures. · f-droid.org, 11 Oct 2026
Integrations: The app can use downloadable spam databases such as the FTC Do Not Call registry and query online services such as PhoneBlock. · github.com, 11 Oct 2026
Known limitations: The project lists no plan for automatic SMS clearing, RCS support, or Android 9 and earlier. · github.com, 11 Oct 2026
License: The project is released under the MIT License. · github.com, 11 Oct 2026
Permissions: The project describes all listed Android permissions as optional and explains they support features such as call control, contact matching, SMS screening, and calendar-based rules. · github.com, 11 Oct 2026
Privacy: The README says offline features collect no data; for online features the API server sees the IP address, TLS/TCP fingerprints, and reported number. · github.com, 11 Oct 2026
Purpose: SpamBlocker blocks unwanted calls and SMS without replacing the default call or SMS app. · github.com, 11 Oct 2026
Reporting: Users can automatically or manually report numbers to crowd-sourced databases. · github.com, 11 Oct 2026
SMS behavior: SpamBlocker takes over SMS notifications, so users should disable notifications from their SMS app to avoid duplicates. · github.com, 11 Oct 2026
SMS filters: SMS features include blocking OTP floods, spam database checks, and training a local AI spam SMS filter. · github.com, 11 Oct 2026
SMS limitation: The app's SMS log contains received messages only, not sent messages. · github.com, 11 Oct 2026