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Cybersecurity · head to head

Cosign vs Umami

Cosign logo

Cosign

Cybersecurity

Signs and verifies container images and artifacts, with or without managing keys

From
Free
Rated
-
Full reviewWebsite
Umami logo

Umami

Marketing

Open source, cookie-free web analytics you can self-host for the cost of a database

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Cosign keyless signing inherits every weakness of the identity provider behind it. Sigstore’s own threat model states that if an identity provider is compromised, Sigstore will issue certificates to those identities, so a compromised account produces perfectly valid signatures.; Umami there is no cohort analysis, retention curve, session replay or multi-touch attribution, so a marketing team that needs to justify channel spend will still buy a second tool and Umami becomes a supplementary dashboard.
  • They diverge on capability: Cosign covers Keyless signing, Umami covers Cookie-free tracking.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Cosign and Umami actually diverge.

Attributes where Cosign and Umami differ
AttributeCosignUmami
Pricing modelOpen source, no licence feePer month by event count
PlatformsmacOS, Linux, Windows, DockerWeb, Linux
CategoryCybersecurityMarketing

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

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 Cosign

  • Keyless signing
  • Key and KMS signing
  • Registry-native storage
  • In-toto attestations
  • Offline verification
  • Trusted root and signing config

Only in Umami

  • Cookie-free tracking
  • Self-hosting
  • Small tracking script
  • Custom events
  • Funnels and goals
  • Multi-site and teams
  • Public dashboards
  • API access

What people use each for

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

Cosign

  • Signing container images in a build pipeline without managing long-lived private keysnot Umami
  • Attaching a signed bill of materials to a release so consumers can verify its provenancenot Umami
  • Meeting a customer or regulatory requirement for signed artifactsnot Umami
  • Verifying third-party images before they enter an internal registrynot Umami

Umami

  • A developer who wants traffic numbers on a personal or client site without adding a consent bannernot Cosign
  • An organisation whose legal or procurement team has ruled out sending visitor data to a US advertising companynot Cosign
  • A high-traffic site where hosted analytics priced by pageview band has become expensive and self-hosting removes the ceiling entirelynot Cosign
  • A team that wants analytics data in a database they already control so they can query and join it themselvesnot Cosign

Where each one falls short

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

Cosign

  • Keyless signing inherits every weakness of the identity provider behind it. Sigstore’s own threat model states that if an identity provider is compromised, Sigstore will issue certificates to those identities, so a compromised account produces perfectly valid signatures.
  • A signature proves who signed, never whether they should have. The documentation is explicit that Sigstore cannot determine authorisation, so every consumer must write and maintain their own identity and issuer policy or verification means nothing.
  • Nothing is enforced without an admission controller. Signing changes what you can prove, not what runs, and the official policy controller has a small maintainer base for a component sitting in a cluster admission path.
  • Upgrades break pipelines. Version 3 changed defaults, version 4 is announced as removing legacy functionality and roughly half the command line flags, and two official client libraries still lacked support for the new log format as of mid 2026.
  • Signatures do not expire. An artifact signed before a maintainer account was compromised and one signed after are indistinguishable unless somebody is actively monitoring the transparency log, and almost nobody is.

Umami

  • There is no cohort analysis, retention curve, session replay or multi-touch attribution, so a marketing team that needs to justify channel spend will still buy a second tool and Umami becomes a supplementary dashboard.
  • Self-hosting is only free in licence terms; you own the database, the upgrades, the backups and the query performance at scale, and a busy site's events table grows quickly enough to need real attention.
  • Because it stores no persistent identifier, it cannot follow a user across devices or sessions in any meaningful way, which makes returning-visitor and lifetime-value questions unanswerable by design rather than by omission.
  • Cloud overage is billed per event beyond the plan allowance, so a traffic spike or a badly instrumented custom event can produce a bill materially above the $20 or $200 headline before anyone notices.
  • It is maintained by a small team, so the pace of new capability is modest and enterprise expectations such as SSO, granular role permissions and formal support agreements are limited compared with commercial analytics vendors.

Pricing, plan by plan

Cosign

Free
  • CosignFree
    • Apache-2.0
    • Public Sigstore infrastructure free to use
    • No usage limits published

Umami

Free
  • Self-hostedFree
    • MIT licensed, no licence fee
    • No event limit imposed by the software
    • Unlimited websites and users
  • Cloud HobbyFree
    • Up to 100,000 events per month
    • 3 websites
    • 6 months data retention
  • Cloud Pro$20/month
    • Up to 1,000,000 events per month
    • Unlimited websites
    • Unlimited team members
  • Cloud Business$200/month
    • Up to 10,000,000 events per month
    • All Pro features
    • Higher volume overage rate

Which should you pick?

Choose Cosign if

  • You need keyless signing.
  • You want to start without paying.
  • You work on macOS, Linux, Windows, Docker.
  • You also want key and kms signing.
Cosign review

Choose Umami if

  • You need cookie-free tracking.
  • You want to start without paying.
  • You work on Web, Linux.
  • You also want self-hosting.
Umami review

Questions people ask

Is Cosign or Umami better?
Neither clearly leads. Cosign starts at Free and Umami at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Umami?
Cosign starts at Free and Umami at Free.
Does Cosign or Umami run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Umami runs on Web, Linux.
Can I use Cosign for free?
Both have a free tier, so you can try either at no cost before committing.
What is Cosign best used for?
Cosign is most often used for signing container images in a build pipeline without managing long-lived private keys, attaching a signed bill of materials to a release so consumers can verify its provenance, meeting a customer or regulatory requirement for signed artifacts, verifying third-party images before they enter an internal registry. Of those, signing container images in a build pipeline without managing long-lived private keys and attaching a signed bill of materials to a release so consumers can verify its provenance are not what Umami is typically brought in for.
What can Cosign do that Umami cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Umami covers Cookie-free tracking, Self-hosting, Small tracking script, Custom events.

Answered from the vendors’ own pages

Cosign: Does Cosign tell me if an image is vulnerable?

No. It has no vulnerability knowledge whatsoever. It can carry an SBOM as a signed attestation but never reads it. Pair it with a scanner.

Umami: Is Umami really free?

Self-hosted, yes; it is MIT licensed with no event cap. You pay for the server and database. Umami Cloud has a free tier at 100,000 events a month and paid tiers from $20.

Cosign: Is signing alone enough?

No. Verification is a command somebody runs. Without an admission controller enforcing it, an unsigned image still runs.

Umami: Do I need a cookie consent banner?

For Umami analytics specifically, generally no, because it sets no cookies and stores no personal data. Other tags on your site may still require one.

Cosign: What does a bare cosign verify actually prove?

Very little. Without a pinned certificate identity and OIDC issuer, it accepts a valid signature from any identity at all.

Umami: Can it replace Google Analytics?

For traffic, referrers and event counts, yes. For attribution modelling, audiences and advertising integration, no.

Cosign: What is the risk of keyless signing?

Your OIDC provider becomes the root of trust. Compromise of that account yields genuine, verifiable signatures, so account security is the control that matters.

Umami: What does it need to run?

A container and a PostgreSQL or MySQL database. Most people deploy it on infrastructure they already pay for.

Cosign: Should we expect breaking changes?

Yes. Version 4 is announced to remove roughly half the flags, and a post-quantum migration is named as a further breaking change after that.

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