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Cybersecurity · head to head

Cosign vs Harness

Cosign logo

Cosign

Cybersecurity

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

From
Free
Free plan
Yes
Full reviewWebsite
Harness logo

Harness

Developer Tools

Software delivery platform across CI, CD, security testing and cost management

From
Free
Free plan
Yes
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.; Harness essentials and Enterprise pricing requires sales contact; no published rates
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Cosign and Harness actually diverge.

Attributes where Cosign and Harness differ
AttributeCosignHarness
Pricing modelOpen source, no licence feefreemium
PlatformsmacOS, Linux, Windows, DockerWeb
CategoryCybersecurityDeveloper Tools

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 Harness

Nothing recorded that Cosign does not also cover.

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 Harness
  • Attaching a signed bill of materials to a release so consumers can verify its provenancenot Harness
  • Meeting a customer or regulatory requirement for signed artifactsnot Harness
  • Verifying third-party images before they enter an internal registrynot Harness

Harness

  • Deploying apps to AWS, Azure, and Google Cloud with rollbacksnot Cosign
  • Integrating security scanners throughout build pipelines before productionnot Cosign
  • Automating cloud cost reduction and tracking unit-level expensesnot Cosign
  • Enabling developers to provision infrastructure without operations bottlenecksnot Cosign
  • Assessing deployment frequency and lead time productivity metricsnot 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.

Harness

  • Essentials and Enterprise pricing requires sales contact; no published rates
  • DevOps Essentials has no on-premises deployment option
  • Internal Developer Portal requires minimum 20 developer licenses
  • Pipeline execution history retention 6 months (Essentials) vs 25 months as add-on (Enterprise)

Pricing, plan by plan

Cosign

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

Harness

Free
  • FreeFree
    • Starter platform for software delivery lifecycle
    • Open source options available (Harness Open Source, Litmus Chaos)
  • Essentials$null/month
    • Growing organizations with small to mid-size teams
    • Packaged DevOps Essentials bundle
    • Continuous software delivery capabilities
  • Enterprise$null/month
    • Large-scale organizations
    • Pick any modules based on needs
    • Advanced features

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 Harness if

  • You want to start without paying.
Harness review

Questions people ask

Is Cosign or Harness better?
Neither clearly leads. Cosign starts at Free and Harness at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Harness?
Cosign starts at Free and Harness at Free.
Does Cosign or Harness run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Harness runs on Web.
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 Harness is typically brought in for.
What can Cosign do that Harness cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations.

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.

Harness: Is there a free Harness plan?

Yes, Harness offers a free plan for individual developers and small teams with open source options including Harness Open Source and Litmus Chaos.

Source
Cosign: Is signing alone enough?

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

Harness: What are Harness's paid pricing tiers?

Harness offers Essentials for growing teams and Enterprise for large-scale organizations. Both require contacting sales for custom pricing. Pricing is based on modules and features selected.

Source
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.

Harness: Can Harness be deployed on-premises?

Enterprise plans include self-managed platform deployment option. DevOps Essentials bundle does not offer on-premises deployment.

Source
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.

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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