Signal vs Mozilla Thunderbird

Signal: what it's good at

Signal provides end-to-end encrypted messaging, voice and video calls by default, collects essentially no metadata, and is run by a non-profit foundation. Its encryption protocol is the one other messengers license.

• End-to-end encryption on by default
• Minimal metadata collection
• Encrypted voice and video calls
• Run by a non-profit, funded by donations

Mozilla Thunderbird: what it's good at

Thunderbird is a full desktop email client handling unlimited accounts across IMAP, POP and Exchange-compatible services, with an integrated calendar, address book and strong message search. The standard free Outlook alternative.

• Unlimited email accounts
• Integrated calendar and contacts
• Powerful search and message filters
• OpenPGP end-to-end encryption built in

Which should you choose?

Both are free, so the honest answer is that you can install either and decide for yourself — that is the advantage of free software over a paid trial.

Both run on Windows, macOS, Linux. Only Signal supports Android, iOS. Both are open source, so neither locks you in.

We deliberately do not publish a star rating for either. We have no way to verify a rating that would be honest at scale, and an invented one would be worse than none — so we give you the facts and let you decide.

Frequently asked questions

Is Signal better than Mozilla Thunderbird?

Neither is universally better. Signal the privacy benchmark for encrypted messaging, while Mozilla Thunderbird the leading free desktop email client. The right pick depends on your platform and workflow.

Are both really free?

Signal is open source and Mozilla Thunderbird is open source. Both can be downloaded without paying.

Can I install both?

Yes. Since neither costs anything, installing both and comparing them on your own files is usually the fastest way to decide.