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Cybersecurity · head to head

Sigstore vs Tuta

Sigstore logo

Sigstore

Cybersecurity

Free public signing and transparency infrastructure for open source artifacts

From
Free
Rated
-
Full reviewWebsite
Tuta logo

Tuta

Cybersecurity

Secure, green and ad-free. Email to feel good about.

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Sigstore the security model depends on somebody watching the log. The documentation states that compromise of an identity provider or of Fulcio itself is detectable only if third parties monitor the transparency log, the monitoring tool is a community-tier rather than core project, and almost no consumer runs one.; Tuta individual plan pricing only shown in EUR; no USD conversion provided on site
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Sigstore and Tuta actually diverge.

Attributes where Sigstore and Tuta differ
AttributeSigstoreTuta
Pricing modelOpen source, public instance free to usefreemium
PlatformsWeb, Linux, macOS, Windows, Self-hostedWeb

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Cybersecurity).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Sigstore

  • Fulcio
  • Rekor
  • Keyless signing
  • Multi-language clients
  • Timestamp authority
  • Neutral governance

Only in Tuta

Nothing recorded that Sigstore does not also cover.

What people use each for

The jobs each tool is most often brought in to do.

Sigstore

  • Open source projects signing releases without running a certificate authoritynot Tuta
  • Organisations meeting a signed-artifact requirement without buying a signing productnot Tuta
  • Publishing provenance that a consumer can verify independently of younot Tuta
  • Self-hosting the same components where a public log is unacceptablenot Tuta

Tuta

  • Private encrypted email communicationnot Sigstore
  • Users valuing end-to-end encryption and zero-knowledge architecturenot Sigstore
  • Individuals seeking open-source email clientsnot Sigstore
  • Organizations requiring quantum-resistant encryptionnot Sigstore

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Sigstore

  • The security model depends on somebody watching the log. The documentation states that compromise of an identity provider or of Fulcio itself is detectable only if third parties monitor the transparency log, the monitoring tool is a community-tier rather than core project, and almost no consumer runs one.
  • It is a 99.5 percent objective with no service level agreement, which permits several hours of downtime a month and offers no remedy. A pipeline that signs on every build has taken a hard dependency on a free service with no contract behind it.
  • Log scale is a live engineering problem rather than a theoretical one. The active shard holds billions of entries, the log has already been sharded twice, and sharding version 1 requires stopping traffic, which is why a replacement was built.
  • Ten-minute certificates make trust depend on log availability. Verifying an older signature relies on the log entry proving it was made inside that window, so a lost or unreachable entry can render a valid artifact unverifiable.
  • Migration debt is substantial and ongoing. Version 2 of the log is generally available but not the public default, the signing client has an announced breaking release ahead, some official clients lag the new log format, and a post-quantum migration is named as the next break after that.

Tuta

  • Individual plan pricing only shown in EUR; no USD conversion provided on site
  • Family plan pricing separate (EUR 3 or EUR 8 per additional user) not included in main pricing
  • Shared mailboxes require additional EUR 3-8 monthly charges

Pricing, plan by plan

Sigstore

Free
  • Public good instanceFree
    • Free to everyone with no contract
    • 99.5 percent availability objective, not an agreement
    • 100KB cap per attestation upload
  • Self-hostedFree
    • Apache-2.0
    • Run your own Fulcio and Rekor
    • Rekor v2 available for self-hosters

Tuta

Free
  • Free PlanFree
    • 1 GB storage
    • 1 calendar
    • 3 labels
  • Revolutionary Plan$3/month
    • 20 GB storage
    • 15 email aliases
    • 3 custom domains
  • Legend Plan$8/month
    • 500 GB storage
    • 30 email aliases
    • 10 custom domains

Which should you pick?

Choose Sigstore if

  • You need fulcio.
  • You want to start without paying.
  • You work on Web, Linux, macOS, Windows, Self-hosted.
  • You also want rekor.
Sigstore review

Choose Tuta if

  • You want to start without paying.
Tuta review

Questions people ask

Is Sigstore or Tuta better?
Neither clearly leads. Sigstore starts at Free and Tuta at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Sigstore or Tuta?
Sigstore starts at Free and Tuta at Free.
Does Sigstore or Tuta run on more platforms?
Sigstore runs on Web, Linux, macOS, Windows, Self-hosted. Tuta runs on Web.
Can I use Sigstore for free?
Both have a free tier, so you can try either at no cost before committing.
What is Sigstore best used for?
Sigstore is most often used for open source projects signing releases without running a certificate authority, organisations meeting a signed-artifact requirement without buying a signing product, publishing provenance that a consumer can verify independently of you, self-hosting the same components where a public log is unacceptable. Of those, open source projects signing releases without running a certificate authority and organisations meeting a signed-artifact requirement without buying a signing product are not what Tuta is typically brought in for.
What can Sigstore do that Tuta cannot?
Sigstore covers Fulcio, Rekor, Keyless signing, Multi-language clients.

Answered from the vendors’ own pages

Sigstore: Is the public instance really free?

Yes, with no contract and no paid tier. That is also the weakness: a 99.5 percent objective with no agreement, no remedy and support through Slack.

Tuta: How much does Tuta email cost?

Tuta offers a free plan with 1 GB storage. Paid plans are EUR 3/month (Revolutionary) with 20 GB storage and 15 email aliases, and EUR 8/month (Legend) with 500 GB storage and 30 email aliases. Family plan add-ons cost EUR 3-8 per additional mailbox member monthly.

Source
Sigstore: Has the public log moved to Rekor v2?

No. Version 2 reached general availability in October 2025 and self-hosters can use it, but the public instance still defaults to version 1 and the project has said it will for the foreseeable future.

Tuta: Is there a free email plan with Tuta?

Yes, Tuta's free plan includes 1 GB of storage, one calendar, three labels, and full end-to-end encryption security features with no custom domains or email aliases.

Source
Sigstore: Does Sigstore make my dependencies safe?

No, and this is a category error worth avoiding. It tells you who published something. It has no knowledge of what the artifact contains or whether it is vulnerable.

Tuta: What are the limits on Tuta's free email plan?

The free plan provides 1 GB storage, access to one calendar, three labels maximum, and no support for custom domains or additional email aliases.

Source
Sigstore: What are the rate limits?

Not published. Only the 100KB cap per attestation upload is documented, so do not design a high-volume pipeline around assumed throughput.

Sigstore: Should we self-host it?

If a public record of every signature is unacceptable, or if a free service with no agreement cannot sit in your build path, then yes. Otherwise the public instance is what most projects use.

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