Firefox Fast & Private Browser v4.0b3
APK · 13.4 MB · version code 1 · Android 2.0+ · uploaded Nov 9, 2025
- Signature matches the Google Play version Details
Quick check before downloading
Answer this to unlock the download. It keeps automated downloaders away.
Compared with the latest version
The latest version is v157.0.1, uploaded Oct 6, 2026 — about 11 months after this one.
- Size: this file is 13.4 MB; the latest is 128.1 MB (114.6 MB larger).
- Android: this version needs Android 2.0+; the latest needs Android 8.0+. Use this one if your device runs an older Android release.
- The latest version asks for 30 more permissions: Approximate location, Access local network, View network connections, Camera, Credential manager query candidate credentials, Credential manager set origin, Download without notification, Run foreground services….
- The latest version no longer asks for: Modify shared storage, Add home-screen shortcuts.
File information
- Version
- v4.0b3 (1)
- Uploaded
- Nov 9, 2025
- Size
- 13.4 MB
- Requires
- Android 2.0+ (API 5)
- CPU support
- ARM 32-bit
- Screen
- Small screens and larger
- MD5
- e51644f5c307b4074f2b5b667102da92
- Signing certificate (SHA-1)
- 92:0F:48:76:A6:A5:7B:4A:6A:2F:4C:CA:F6:5F:7D:29:CE:26:FF:2C
- Signed by
- CN=Release Engineering, OU=Release Engineering, O=Mozilla Corporation, L=Mountain View, ST=California, C=US
- File name
- org-mozilla-firefox-1-72233845-e51644f5c307b4074f2b5b667102da92.apk
- Package
- org.mozilla.firefox
- Downloads (all versions)
- 500M+
- Age rating
- PEGI 3 · Everyone
What's new in v4.0b3
Thanks for choosing Firefox! Here's what's new:
- (144.0.1) Fixed an issue where the bottom toolbar could be hidden by the keyboard.
- Translations banner: see if a page is fully translated or still in progress.
- Tracking Protection: panel shows how your privacy is protected on each site you visit.
- Platform update: Firefox now requires Android 8 or later to ensure continuous improvements to performance and security.
Have feedback? Let us know at https://mzl.la/AndroidSupport.
Permissions (4)
This version requests 4 permissions, 2 of them sensitive.
- Modify shared storage Sensitive android.permission.WRITE_EXTERNAL_STORAGE
- Precise location Sensitive android.permission.ACCESS_FINE_LOCATION
- Add home-screen shortcuts com.android.launcher.permission.INSTALL_SHORTCUT
- Full network access android.permission.INTERNET
Security & authenticity
Security rating: Trusted
Signing certificate
- Signature matches the Google Play version Checked by the source store on Nov 9, 2025.
- Certificate issued to “Mozilla Corporation” This is the certificate of the Google Play version.
- Same certificate as the 6 other versions checked
Store checks
- Developer signature not checked yet Nov 9, 2025
- Validated against Google Play Nov 9, 2025
- Uploaded by “appupdater” Gold tier · 117,810 followers · uploading since 2020
Scans come from the source store; the certificate comparisons are AAPKs's own, made from the files' published signatures (6 other versions compared). AAPKs doesn't scan files itself.
How to install Firefox Fast & Private Browser on Android 2.0+
You'll need about 26.8 MB of free space.
- Download the APK — tap Download APK above (13.4 MB). Chrome shows “File might be harmful” for every APK file; choose Download anyway only if you trust this file.
- Open the file — tap the download notification, or open Files › Downloads and tap org-mozilla-firefox-1-72233845-e51644f5c307b4074f2b5b667102da92.apk.
- Allow the install (first time only) — Android 8 and later asks for permission the first time an app opens an APK: tap Settings in the prompt, turn on Allow from this source, then go back. Manual path: Settings › Apps › Special app access › Install unknown apps (on Samsung: Settings › Apps › ⋮ › Special access). On Android 7 and older: Settings › Security › Unknown sources.
- Check the file (optional) — the MD5 of the downloaded file should be e51644f5c307b4074f2b5b667102da92. If it differs, the file is damaged or was changed: delete it and download again.
- Tap Install — Android asks “Do you want to install this app?”. If Google Play Protect shows a warning, read it before you continue: the source store rated this file Trusted, but only install apps from sources you trust. If an earlier version is installed, this one only installs as an update when it is signed with the same certificate (SHA-1 shown above).
- Open Firefox Fast & Private Browser — tap Open on the install screen, or find it in your app drawer.
Common install problems
- “App not installed” — a version signed with a different certificate, or a newer version, is already installed (Android doesn't allow downgrades). Uninstall it first; back up your data, because uninstalling deletes it.
- “There was a problem parsing the package” — the file is incomplete, or your Android is too old (this version needs Android 2.0+). Download it again, or pick an older version.
- “App not compatible with your device” — this build contains native code for ARM 32-bit only. Devices with other processors can't install it.
- Blocked by Play Protect — Play Protect checks apps from outside the Play Store. Only continue if you trust the source.