KnownCalls is a new, completely free call blocker for Android that helps you combat spam calls while protecting your privacy.
With KnownCalls, your phone will automatically reject calls from numbers not in your contacts. It will save you time wasted on answering spam calls and messages, and make you a less attractive target for fraudsters.

No internet connection is required – the app does not use external resources. It works solely with your device’s contacts!

Modern spammers usually call from different numbers each time, so adding each number to a block list may be ineffective – they might use another number the next time they call. Similarly, other call-blocking apps are often ineffective as they usually work with a delay: they need to store your phone calls in a common database and gather enough information to determine if a number belongs to a spammer, only then does the block work. However, with that mechanism, you might be among the first recipients they still get through to. But not with KnownCalls! KnownCalls uses only your device’s contacts, so rejecting unknown callers is instantaneous. KnownCalls does not collect or send information about your phone calls anywhere!

To learn more about the difference between the SMS muting version and the version without SMS muting, read this article

How to scan a QR code:

1. Use a mobile phone or tablet with a camera.
2. Open the camera app and point your camera at the QR code.
3. The QR code will then be ‘recognized’, and you’ll be redirected to the chosen platform.
4. Once there, download and install the free KnownCalls call blocker app for your Android device.

KnownCalls stands out from other call blocking apps due to its simplicity and terms of use:

Several levels of whitelisting: blocks calls not from Contacts or Favorites.
Mutes unwanted text messages.
No personal data is stored or sent anywhere. See our privacy policy
An internet connection is not required.
No ads.
Easy 1-click functionality.
Installs well on almost any modern Android device with Android OS 10 and up.

Stop annoying calls from call centers, telemarketers, fraudsters, and robocalls that always interrupt you!
Finally, you can enjoy silence – and be sure that trusted callers will get through.

This app is for those who don’t answer calls from unknown numbers and want to stop receiving them: people who want to be contacted only by their acquaintances listed in their Phonebook, children, seniors, business people who have secretaries for managing new client contacts, etc.
This app is not for you if you want to receive calls from unknown numbers regularly. Alternatively, if you’re waiting for a delivery, you can temporarily disable the app or add the courier’s phone number to your Contacts.

* Download KnownCalls – Call Blocker from Google Play or our website and install it on your device.
Activate filtering with a single click.
Done! All calls from numbers not in your Contacts or Favorites will be automatically rejected, without interrupting you. Plus, the website version lets you mute text messages too

See more in the setup guide

Note:
On Android 10 devices, rejected calls will not appear in the device’s call log (the ‘Recents’/’History’/’Dialer’ tab in the Contacts app).
On Android 11 and later devices, rejected calls will be logged in the device’s call log (the ‘Recents’/’History’/’Dialer’ tab in the Contacts app), so you can always verify that the app is working and that rejected calls are indeed from unknown numbers.

Important: Free app distribution – no technical support is included. Check the forum or the “KnownCalls, call blocker: Troubleshooting common issues” article for assistance.

The KnownCalls app is an ideal call blocker for:

* Parental control: protect your children by creating a whitelist of trusted numbers and blocking calls from all other numbers.
* Public figures: reduce distracting phone calls while remaining accessible to known contacts.
* Business professionals: let KnownCalls automatically filter out spam call center noise, while still allowing calls from your Contacts.
* Senior protection: prevent scammers from taking advantage of vulnerable elderly individuals by blocking calls from unknown numbers.

KnownCalls offers a unique combination of privacy protection, ease of use, and accessibility. The app is free. Plus, it doesn’t require an internet connection
KnownCalls does not collect, store, or transmit your personal information.

If you are a business owner, politician, or public figure, your number is likely publicly available. This means you are probably tired of endless spam and other unwanted calls that you can’t get rid of, as you need to be accessible to customers, suppliers, and authorities.

Now there is a solution – the new free Android app, KnownCalls, is a call filter that blocks calls from unknown numbers, keeping you in touch with the rest of your contacts. No more wasting even seconds of your time answering annoying spam calls

Use KnownCalls – Call Blocker if you are concerned about the increasing number of scammers who could defraud your elderly relatives: block all calls from contacts not in your phone book.

KnownCalls is also an excellent parental control tool. Ensure that children are not intimidated by strangers, yet remain reachable to parents, friends, and school contacts.

KnownCalls’ compounding effect: Spam calls are automatically rejected, progressively removing your number from call center lists.

‘Works perfectly on my child’s Galaxy 10.’
Indira Singh

‘A great app for my Android that blocks unwanted caller IDs.’
Mel Berronger

‘A FREE app with NO ADS that actually WORKS… Is that even possible? Amazing!’
oli oli

Share your experience and help others!

Read all testimonials here (Play Store, also known as Google Play or Android Market, and user feedback)

Have ideas for new app features or improvements? Share them using the form below. Your feedback helps us make the app more convenient and useful for everyone.

June 9, 2025: New version of KnownCalls – 25.06.09 – includes a fix for some crashes. See KnownCalls’ History of Changes

May 7, 2025: The new version of KnownCalls 25.05.07 eliminates requests for excessive permissions and restores KnownCalls to requesting only the most necessary permissions! Now available on our website, coming soon to Google Play.

May 15, 2024: New infographics – troubleshooting for the 3 most common issues: if KnownCalls does not work, if it does not block some unwanted calls, or if it blocks necessary calls. Find the answers on this page.

See more on the History of Changes page

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KnownCalls sitemap: all articles, setup and troubleshooting guides, change history, etc.