Thunderbird
Free, open-source email app for Windows, macOS, Linux and Android
What is Thunderbird?
Thunderbird is a free, open-source email app with a calendar, contacts and tasks built in. The desktop version runs on Windows, macOS and Linux and the mobile version on Android, and both handle several accounts separately or in a unified inbox. It is funded by donations rather than ads or data sales, and is developed by MZLA Technologies Corporation, a subsidiary of Mozilla.
Thunderbird is free to use. See every plan
Good for
- People who want a free desktop email app without ads
- Linux users, and anyone moving between Windows, macOS and Linux
- Those who prefer open-source software for mail and calendar
Worth knowing
- Thunderbird Mobile is listed for Android only, through Google Play and F-Droid. No iPhone or iPad app is listed.
- It is a mail client, not a mailbox: it connects to accounts hosted elsewhere. The team's own hosting service, Thundermail, is in beta behind a waitlist.
- Thundermail is a separate paid subscription. Its Early Bird Plan is shown at $6 per month, paid annually, with full launch expected in 2026.
- Support is community-based. Thunderbird states that donations do not buy individual technical support.
Key features
- Unified inbox for several accounts
- Keep every email account in one app and read them separately or together in a unified inbox, on desktop and on Android.
- Calendar, contacts and tasks
- The desktop app manages appointments, contacts and tasks alongside email, so scheduling does not need a separate program.
- No ads or data mining
- Thunderbird says it does not sell ads in the inbox, collect personal data or train AI on private conversations. It is funded by user donations.
- Open source and extensible
- The code is published under the MPL 2.0 license for anyone to inspect, modify and share, and add-ons extend what the desktop app can do.
- OpenPGP encryption on Android
- Advanced users can send and receive encrypted mail with the OpenPGP standard by pairing Thunderbird Mobile with the free OpenKeychain app.
- Desktop-to-mobile setup
- Desktop users can move their account settings to the Android app by scanning a QR code shown in the desktop app.
Thunderbird pricing
- Starts at
- Free
- Free plan
- The whole app is free on desktop and Android, with no ads and no paid tier. Development is funded by voluntary donations.
- Free trial
- None listed
| Plan | Price | What you get |
|---|---|---|
| Free | $0 | Every feature of Thunderbird Desktop for Windows, macOS and Linux and of Thunderbird Mobile for Android. |
Read from thunderbird.net on Oct 5, 2026. Prices change, so confirm with Thunderbird before you buy.
Works with
- OpenKeychain
Thunderbird alternatives
- Thunderbird vs Microsoft Outlook
Free plan · from $1.99/mo
- Thunderbird vs eM Client
Free plan · from $39.95/yr
- Thunderbird vs Mailbird
Free plan · from $34.49/yr
- Thunderbird vs Apple Mail
Free plan · from $0.99/mo
- Thunderbird vs Mailspring
Free plan · from $8/mo
Common questions
Is Thunderbird free?
Yes. Thunderbird is free to use. The whole app is free on desktop and Android, with no ads and no paid tier. Development is funded by voluntary donations.
How much does Thunderbird cost?
Thunderbird lists one plan. Free: $0. Prices were read from thunderbird.net on Oct 5, 2026.
What platforms does Thunderbird work on?
Thunderbird is available on Windows, macOS, Linux and Android.
Does Thunderbird have an iPhone app?
No iPhone app was listed when its pages were read on Oct 5, 2026. Thunderbird is listed for Windows, macOS, Linux and Android.
Is Thunderbird open source?
Yes. Thunderbird is open source, according to its own site.
What does Thunderbird integrate with?
Thunderbird's listing names OpenKeychain. A listing names up to eight integrations, so it may connect to more.
Who makes Thunderbird?
Thunderbird is made by MZLA Technologies Corporation. It dates from 2003.
What are the alternatives to Thunderbird?
The closest alternatives to Thunderbird in our directory are Microsoft Outlook, eM Client, Mailbird, Apple Mail and Mailspring. Each one has a side-by-side comparison with Thunderbird.
Sources for this page
The prices, plans, platforms and features above were read from these pages on Oct 5, 2026.