Is Cosign or KnowBe4 better?

Neither clearly leads. Cosign starts at Free and KnowBe4 at $1/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.

Which is cheaper, Cosign or KnowBe4?

Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and $1/month for KnowBe4.

Does Cosign or KnowBe4 run on more platforms?

Cosign runs on macOS, Linux, Windows, Docker. KnowBe4 runs on Web, Mobile, Email.

Can I use Cosign for free?

Yes. Cosign has a free tier, so you can try it without paying. KnowBe4 starts at $1/month.

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 KnowBe4 is typically brought in for.

What can Cosign do that KnowBe4 cannot?

Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. KnowBe4 covers Security awareness training, Phishing simulation, Risk assessments, Compliance training.

Cybersecurity · head to head

Cosign vs KnowBe4

Cosign

Cybersecurity

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

From: Free
Rated: -

Full review Website

KnowBe4

Cybersecurity

World's largest security awareness training platform

From: $1/month
Rated: -

Full review Website

The short version

Only Cosign has a free tier, so it costs nothing to try first.
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.; KnowBe4 published prices assume a three year term, so the quoted per seat rate depends on a long commitment
They diverge on capability: Cosign covers Keyless signing, KnowBe4 covers Security awareness training.
Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Cosign and KnowBe4 actually diverge.

Attributes where Cosign and KnowBe4 differ
Attribute	Cosign	KnowBe4
Starting price	Free	$1/month
Pricing model	Open source, no licence fee	subscription
Free tier	Yes	No
Platforms	macOS, Linux, Windows, Docker	Web, Mobile, Email
Founded	Unknown	2010

Identical on both: 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 Cosign

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

Only in KnowBe4

Security awareness training
Phishing simulation
Risk assessments
Compliance training
Incident reporting
API access
Custom policies
Behavior analytics

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 KnowBe4
Attaching a signed bill of materials to a release so consumers can verify its provenancenot KnowBe4
Meeting a customer or regulatory requirement for signed artifactsnot KnowBe4
Verifying third-party images before they enter an internal registrynot KnowBe4

KnowBe4

Security awareness training and simulated phishing for staffnot Cosign
Tracking employee susceptibility to phishing over timenot 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.

KnowBe4

Published prices assume a three year term, so the quoted per seat rate depends on a long commitment
Pricing is banded by seat count, and the lowest band of 25 to 50 seats pays the highest rate
Accounts above 1,000 seats have no published price and require a custom quote
Third party integrations, Compliance Plus and PhishER Plus are all separately priced per seat add ons
The Foundation tier carries 200 training modules against more than 1,000 on Advanced, so content volume is the main gate

Pricing, plan by plan

Cosign

Free

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

KnowBe4

$1/month

Basic$1/month
- Per user
- Training modules
- Phishing templates
Advanced$2/month
- All Basic features
- Advanced phishing
- Risk assessments
Pro$3/month
- All Advanced features
- API access
- Custom content

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 KnowBe4 if

You need security awareness training.
You work on Web, Mobile, Email.
You also want phishing simulation.

KnowBe4 review

Questions people ask

Is Cosign or KnowBe4 better?: Neither clearly leads. Cosign starts at Free and KnowBe4 at $1/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or KnowBe4?: Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and $1/month for KnowBe4.
Does Cosign or KnowBe4 run on more platforms?: Cosign runs on macOS, Linux, Windows, Docker. KnowBe4 runs on Web, Mobile, Email.
Can I use Cosign for free?: Yes. Cosign has a free tier, so you can try it without paying. KnowBe4 starts at $1/month.
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 KnowBe4 is typically brought in for.
What can Cosign do that KnowBe4 cannot?: Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. KnowBe4 covers Security awareness training, Phishing simulation, Risk assessments, Compliance training.

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.

KnowBe4: What does KnowBe4 cost per employee?

KnowBe4 charges per seat per month on a subscription basis. For 51-100 employees, SAT Foundation costs $2.13/month per seat and SAT Advanced costs $3.40/month per seat. Prices decrease with larger employee counts.

Source

Cosign: Is signing alone enough?

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

KnowBe4: Does KnowBe4 offer a free trial?

KnowBe4 does not offer a full free version, but free tools are available separately including assessments and simulators.

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.

KnowBe4: Are there add-on costs beyond the base plan?

Yes, optional add-ons include Third-Party Integrations ($1.10-$1.20/seat/month), Compliance Plus ($0.82-$0.93/seat/month), PhishER Plus ($1.15-$1.50/seat/month), and Student Edition ($0.17/seat/month).

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.

KnowBe4: What currencies does KnowBe4 accept?

KnowBe4 accepts pricing in USD, AUD, BRL, CAD, EUR, GBP, SGD, and ZAR.

Source

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.

Cosign vs KnowBe4

Cosign

KnowBe4

The short version

Where they differ

What each one covers

Only in Cosign

Only in KnowBe4

What people use each for

Cosign

KnowBe4

Where each one falls short

Cosign

KnowBe4

Pricing, plan by plan

Cosign

KnowBe4

Which should you pick?

Choose Cosign if

Choose KnowBe4 if

Questions people ask

Answered from the vendors’ own pages

Related pages

More on Cosign

More on KnowBe4

Keep looking

Other head to heads