NumBuster vs PhoneBlock

NumBuster identifies unknown callers and helps users screen phone fraud, spam, and unwanted messages. Its Android app can display caller information during a call and check numbers from the call log. The iPhone app also provides caller information on the call screen and call-log checks, and can block phone numbers. The homepage describes an anti-spam SMS client for Android, while a web app provides phone-number checks and help categories covering free and paid features.

Users can review and rate numbers, contributing community information that may help others assess potential threats. NumBuster says telephone-number information comes from registered users’ activity, not a purchased subscriber directory. A free mobile app is available alongside LIGHT, SMART, and PRO+ subscriptions, whose features vary. Depending on the tier, paid features include removing ads, page access blocking, AI reports, additional page cards, anonymous checks, visitor identification, and more monthly checks. The privacy policy describes safeguards including encryption, access controls, monitoring, backups, and vulnerability management. Non-users can submit privacy and deletion requests through supported website mechanisms without installing the app or creating an account. Feature availability can vary by country, operating system, app version, device, provider, platform capability, or legal circumstances. The terms say the service and mobile apps are not intended for residents of the EU, Bahrain, or the UAE.

PhoneBlock is a free call-blocking service that uses a community-maintained database to identify unwanted advertising and spam calls. Users can report numbers through the app, website, or personal blacklist, and reports join the shared blacklist. The Android app blocks known spam calls, keeps call history, and supports reports and personal lists; it requires Android 10 or later. For incoming calls, the Android app sends only the phone number’s SHA-1 hash and does not access contacts.

Landline users can choose a router dongle, a Fritz!Box cloud answering machine, or a blocklist phonebook synchronized through CardDAV. The documented iPhone setup syncs spam numbers into contacts through CardDAV; a native iPhone app is in development, and beta registration is available. Phone systems can download the blocklist in different formats or query it through an API. PhoneBlock is licensed under GPL-3.0 and operated as a private project. The operator accepts email requests for help, including for mistakenly listed numbers. PhoneBlock costs nothing, with donations optional; its terms advise against business use.