Call Insider vs PhoneBlock

Call Insider is a free caller-identification service available on Android and the web. It helps people assess unknown phone numbers by showing ratings during calls or in a pop-up. The mobile app uses a database with more than 300 million identified numbers, drawing data from more than 100 websites. A downloadable database covering more than 100 countries supports lookups without an internet connection. Users can rate numbers, read other users’ ratings, see yearly interest in a number, and sometimes view a landline location. The service is intended for calls such as telemarketing, surveys, courier contacts, and office calls. Free registration provides fewer ads, editable rating history, reply notifications, more daily comments, and easier reporting of harmful comments. Call blocking for potentially harmful and unsaved numbers is described as in development. The service was created in the Czech Republic in 2011.

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.