Proton Mail vs Tuta 2026: Which Encrypted Email Fits?

Proton Mail and Tuta (the German provider formerly called Tutanota) are the two encrypted email services that meet a serious bar: end-to-end encryption on by default, no plaintext mailbox on the server, open-source clients, and a team that has been operating long enough to be trusted on the unglamorous details.

They make different choices, and the choice between them is mostly about which set of trade-offs you would rather live with. This comparison is drawn from each provider’s published documentation, audit disclosures and official pricing pages, retrieved in August 2026 and linked at the end.

Disclosure: this site has no affiliate relationship with Proton, Tuta, or any provider named here. Nobody paid for placement.

At a glance

	Proton Mail	Tuta
Based in	Switzerland	Germany
Encryption scheme	OpenPGP-based	Proprietary, AES-256 and x25519
Post-quantum encryption	Roadmapped across Proton products	TutaCrypt hybrid shipped March 2024
Subject lines encrypted	No	Yes
IMAP / SMTP	Yes, via Proton Mail Bridge on paid plans	No, by design
PGP interoperability with outside contacts	Yes	No
Client source code	Open source	Open source, GPLv3
Free tier	1 GB Mail plus 5 GB Drive, 1 address	1 GB, 1 address, no aliases
Entry paid plan	Mail Plus, €3.99/mo billed annually	Revolutionary, €3.00/mo billed annually
Custom domains on entry plan	1	3
Search	Local encrypted index per device	Server-side encrypted index
Wider ecosystem	Mail, Calendar, Drive, VPN, Pass, Wallet	Mail and Calendar only

What both do the same

Both encrypt message bodies and attachments between users of the same service so the provider cannot read them. Both store mail at rest encrypted with keys derived from your password, so a server compromise yields ciphertext rather than correspondence. Both support sending encrypted mail to outside addresses through password-protected web links. Both offer custom domains on paid plans, working iOS and Android apps, and a browser client. Both publish their client source code.

If your only requirement is “the provider cannot read my mail”, either one satisfies it and the rest of this page is about fit rather than capability.

Encryption design

Proton Mail builds on OpenPGP. Each account has a PGP key pair; the private key is stored encrypted with your password and decrypted in the client. Because the scheme is standards-based, you can exchange genuinely end-to-end encrypted mail with any PGP user anywhere, import existing keys, and publish your public key for others to use. That interoperability is the single biggest functional advantage Proton holds. If you already have a PGP workflow, our PGP setup guide covers how the keys fit together.

Tuta deliberately does not use OpenPGP. It runs its own scheme built on AES-256 and x25519, and in March 2024 it shipped TutaCrypt, a hybrid protocol combining the post-quantum algorithm CRYSTALS-Kyber with conventional elliptic-curve and symmetric cryptography, making it the first mainstream email provider to encrypt new accounts’ mail against a future quantum adversary. The calendar followed later.

The trade-off is stark and worth stating clearly. Tuta’s scheme protects more of the message — subject lines included — and is quantum-resistant today. It also cannot talk to anyone outside Tuta in encrypted form. Mail to a non-Tuta contact is either an ordinary plaintext message or a password-protected link. There is no path to PGP interoperability, and that is a design position rather than a missing feature.

Subject lines and metadata

Tuta encrypts the subject line of every message. Proton Mail does not: subjects are stored server-side in a form Proton can read, because IMAP compatibility and server-side handling depend on them.

For most people this distinction changes nothing. For anyone whose subject lines are themselves the sensitive part — source protection, legal matters, medical correspondence, whistleblowing — it is the deciding factor, and it points at Tuta unambiguously.

Neither provider encrypts the envelope. Sender, recipient, timestamp and approximate message size remain visible to the provider and to every mail server in the path. That is a property of SMTP, not a failing of either company, and it is covered in detail in what email metadata leaks.

Protocols and client support

Proton supports IMAP and SMTP through Proton Mail Bridge, a local application that decrypts mail on your machine and presents a standard mailbox to Apple Mail, Thunderbird, Outlook or mutt. The Bridge is a paid-plan feature. It is the reason Proton fits into an existing workflow rather than replacing it, and the reason Proton is the realistic choice for anyone with an established desktop mail setup.

Tuta has no IMAP, no SMTP, and no bridge, permanently and on purpose. You use Tuta’s web client, desktop app or mobile apps, or you do not use Tuta. The argument for this is real: no bridge means no local decryption daemon, no app passwords, and a much smaller attack surface. The argument against it is equally real: you are committing to one vendor’s clients for as long as you use the service.

Search

Proton downloads and decrypts a search index locally on each device, so full-text search happens on your hardware over data the server never sees in the clear. It works well and costs local storage.

Tuta indexes encrypted mail server-side using an approach designed so the server can match queries without learning the contents. It is the more technically interesting of the two designs; Proton’s is the more polished in daily use.

Audits and transparency

Proton commissions independent audits from Securitum, a European firm that runs several hundred security testing engagements a year, and publishes the reports rather than summarising them. All Proton client applications are open source, a public bug bounty runs alongside, and Proton publishes periodic transparency reports covering legal requests received and complied with. The combination — open code plus published third-party review plus disclosed legal-request volumes — is the strongest transparency posture in encrypted email.

Tuta publishes its entire client codebase under GPLv3 and states that independent experts audit its applications, but it does not maintain a comparable public index of named, dated third-party assessments. TutaCrypt’s design has been described publicly and reviewed by academic collaborators, which is meaningful, but it is not the same artefact as a downloadable pentest report with a date on it.

Neither company can decrypt your mailbox on request. Both are subject to lawful orders that can compel prospective logging of metadata for a specific targeted account, which is the ceiling on what any provider in either jurisdiction can promise. Treat any claim beyond that as marketing.

Pricing

All figures below come from each provider’s official pricing documentation, retrieved August 2026, in euros. Both companies bill from Europe; the amount charged in other currencies depends on the exchange rate and any regional pricing applied at checkout.

Proton Mail

Plan	Monthly	Annual	Storage	Addresses	Custom domains
Proton Free	€0	€0	1 GB Mail plus 5 GB Drive	1	0
Mail Plus	€4.99/mo	€47.88/yr (€3.99/mo)	15 GB shared with Drive	up to 10	1
Proton Unlimited	€12.99/mo	€119.88/yr (€9.99/mo)	500 GB shared	up to 15 extra	3
Proton Duo	€19.99/mo	€179.88/yr (€14.99/mo)	2 TB shared	30	3
Proton Family	€29.99/mo	€287.88/yr (€23.99/mo)	3 TB shared	90	3

Proton Unlimited and above bundle VPN, Drive, Pass and SimpleLogin premium alongside Mail, which is the calculation that makes them competitive despite the headline number: you are buying a stack, not a mailbox.

Tuta

Plan	Price	Storage	Aliases	Custom domains
Free	€0	1 GB	0	0
Revolutionary	€3.00/mo billed annually	20 GB	15	3
Legend	€8.00/mo billed annually	500 GB	30	10

Tuta’s paid tiers include unlimited addresses on your own custom domains, plus catch-all — and crucially, custom-domain addresses do not count against the 15 or 30 alias limit. That detail makes Revolutionary the cheapest credible route to a custom-domain encrypted mailbox available anywhere, and it is why the pricing comparison does not reduce to the headline monthly figure. Family pricing is available at the same per-user rates on request.

The honest price read: if you want one encrypted mailbox on your own domain and nothing else, Tuta Revolutionary at €3.00/month is the cheaper and better-specified option — more storage than Mail Plus, three domains instead of one. If you want encrypted mail plus VPN, cloud storage and a password manager under one subscription, Proton Unlimited is better value than assembling those separately. See custom domain vs provider address for whether you need a domain at all.

Which one to pick

Pick Proton Mail if:

• You want existing mail clients to keep working, through the Bridge
• You exchange PGP mail with people outside your provider
• You want one subscription covering mail, VPN, storage and passwords
• You want the strongest published audit and transparency record
• You expect to want built-in aliases later, via the included SimpleLogin integration

Pick Tuta if:

• Subject-line privacy matters for your threat model
• You want post-quantum encryption on your mail today rather than on a roadmap
• You want the cheapest path to custom-domain encrypted email
• You prefer a small focused service over a stack, and a smaller attack surface over protocol flexibility
• Signing up without a phone number is a hard requirement — see free encrypted email without a phone number

Pick neither if:

Your correspondents will not switch and you need every message encrypted end to end. Both services fall back to plaintext or a password-protected link when writing to non-users, and a link nobody opens is not encryption. If your peers already use PGP, a conventional provider with PGP configured in your own client may serve you better than either.

Verdict

Overall: Proton Mail for most people, Tuta for anyone whose threat model includes subject lines or a quantum-capable future adversary.

• Proton wins on interoperability, client flexibility, published audits, ecosystem value and polish. The Bridge alone decides it for anyone with an established desktop mail workflow, and OpenPGP support means you are not cut off from encrypted correspondence outside the service.
• Tuta wins on how much of the message it protects, on shipping post-quantum encryption first rather than promising it, and on price per unit of custom-domain capability. Its cost is total commitment to Tuta’s own clients and no encrypted contact with the PGP world.
• What neither fixes: metadata. Who you mail, when, how often and from what network stays visible regardless of which you choose. If that is the sensitive part, encrypted email alone is not the answer — you want anonymous account creation, connection-level privacy, and discipline about naming and timing on top of it.

For everyday correspondence where you simply do not want a corporate provider building a profile from your mail, either service is a substantial upgrade over Gmail or Outlook, and the migration is easier than most people expect: our Gmail migration guide covers the sequence, and setting up a custom domain covers the DNS records. If you would rather answer a few questions than weigh every row above, the find-your-setup wizard turns your actual constraints into a recommended provider, alias strategy and migration plan.

Related across the network

• How to Set Up PGP for Email: GPG, Thunderbird, Proton — securemailguide.com
• Proton Mail vs Gmail Privacy Comparison: Which Protects You? — securemailguide.com

Related on this site

• Best Encrypted Email for Small Business 2026