Compare software

FlowCryptMailvelope
Freemium

Free extension for individuals, with paid business plans listed on the pricing page.

 Free

Free and open source for personal use. Business products are paid.

Browser extension Browser extension
  • Works inside the normal Gmail interface
  • Encrypts both messages and attachments
  • Works inside existing webmail rather than requiring a desktop mail client
  • Keys stay in the browser under your control
  • Built around Gmail rather than other mail providers
  • Business features require a paid plan
  • Only supports a defined list of webmail sites
  • Browser-based key storage is weaker than a dedicated client or smartcard
Browser extension Browser extension
Closed source Open source
License not stated License: AGPL-3.0
Not stated if an account is needed Not stated if an account is needed
Needs internet Not stated if it works offline

Checked September 24, 2026

Checked September 22, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.