Thunderbird Beta for Testers (f-droid version) Icon

Download Thunderbird Beta for Testers (f-droid version) APK Thunderbird Beta for Testers (f-droid version) arm64-v8a, armeabi-v7a, x86, x86_64 · Android 21+

By Mozilla Thunderbird • Updated December 16, 2025
Communication arm64-v8a, armeabi-v7a, x86, x86_64 Native (Java/Kotlin) 12.33 MB
Download APK
Verified Safe

This is the arm64-v8a, armeabi-v7a, x86, x86_64 build of Thunderbird Beta for Testers (f-droid version) Thunderbird Beta for Testers (f-droid version). Pick this build if your device's primary ABI matches.

File size: 12.3 MB   •   Min Android: 21   •   Target Android: 35   •   Version code: 39030   •   Framework: Native (Java/Kotlin)   •   Permissions: 16

File Information

Package Namecom.fsck.k9
Version NameThunderbird Beta for Testers (f-droid version)
Version Code39030
Architecturearm64-v8a, armeabi-v7a, x86, x86_64
Min Android VersionAndroid 21 (API 35)
Main Activitycom.fsck.k9.activity.MessageList
FrameworkNative (Java/Kotlin)
File Size12.33 MB
Signature (SHA1)A8240C05184D797C87EFED01D907961F8B4AD62B
File Hash (SHA256)943c715bfe2668012aa8300fa2329572b8c1293adc5b4aac8ce2f0a46782773c

What's New

New in version 14.0
- 'Auto-fit messages' setting did not persist
- Edge-to-edge move/copy regressed with 3-button nav
- Swiping message left/right could abort prematurely
- Outlook SMTP failed authentication for some accounts
- Gmail folder prefixes appeared after refreshing folder list
- Quiet time preferences were ignored
- Thunderbird could crash after deleting an account

App Description

K-9 Mail is an open source email client that works with basically every email provider.

Features

* Supports multiple accounts

* Unified Inbox

* Privacy-friendly (no tracking whatsoever, only connects to your email provider)

* Automatic background synchronization or push notifications

* Local and server-side search

* OpenPGP email encryption (PGP/MIME)

Install the app

OpenKeychain: Easy PGP

to encrypt/decrypt your emails using OpenPGP.

Support

If you're having trouble with K-9 Mail, ask for help in our

support forum

.

Want to help?

K-9 Mail is a community developed project. If you're interested in helping to improve the app, please join us!

You can find our bug tracker, source code, and wiki at

https://github.com/thunderbird/thunderbird-android

.

We're always happy to welcome new developers, designers, documenters, translators, bug triagers and friends.

License:

Apache License 2.0

Website

Issue Tracker

Translation

Source Code

Changelog

Build Metadata

Reproducibility Status

APK Permissions 16

  • android.permission.ACCESS_NETWORK_STATE
  • android.permission.CAMERA
  • android.permission.FOREGROUND_SERVICE
  • android.permission.FOREGROUND_SERVICE_DATA_SYNC
  • android.permission.FOREGROUND_SERVICE_SPECIAL_USE
  • android.permission.INTERNET
  • android.permission.POST_NOTIFICATIONS
  • android.permission.READ_CONTACTS
  • android.permission.READ_SYNC_SETTINGS
  • android.permission.RECEIVE_BOOT_COMPLETED
  • android.permission.SCHEDULE_EXACT_ALARM
  • android.permission.USE_BIOMETRIC
  • android.permission.USE_FINGERPRINT
  • android.permission.VIBRATE
  • android.permission.WAKE_LOCK
  • com.fsck.k9.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
APK Verified

The cryptographic signature guarantees that the file is safe to install and was not tampered with in any way.

Developer

Name: Mozilla Thunderbird

See All Versions View on Google Play

Frequently Asked Questions about Thunderbird Beta for Testers (f-droid version) APK

This variant is built for devices that report `arm64-v8a, armeabi-v7a, x86, x86_64` as their primary ABI. If your device's CPU matches, this is the smallest, fastest version to install.

Yes — the APK's signature has been cryptographically verified against the publisher's signing key. The SHA-256 hash is shown in the File Information panel so you can independently confirm the file matches the original release.

Android 21 (API level 35) or newer. Older devices will refuse the install.

Install a free app like 'CPU-Z' or 'Droid Hardware Info' from the Play Store and look at the ABI / Instruction Set row. Most phones made after 2017 are arm64-v8a; if in doubt, download the universal variant.

All variants are functionally identical — same features, same version. They differ only in which CPU architectures the native code is compiled for, and (sometimes) which screen densities the included graphics target. Pick the one that matches your device for the smallest install size, or pick 'Universal' if you're unsure.