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Cybersecurity · head to head

Sigstore vs WarpBuild

Sigstore logo

Sigstore

Cybersecurity

Free public signing and transparency infrastructure for open source artifacts

From
Free
Free plan
Yes
Full reviewWebsite
WarpBuild logo

WarpBuild

Developer Tools

2x faster, 50% cheaper GitHub Actions runners

From
On request
Free plan
No
Full reviewWebsite

The short version

  • Only Sigstore has a free tier, so it costs nothing to try first.
  • 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.; WarpBuild per-minute pricing requires tracking usage to estimate monthly costs
  • They diverge on capability: Sigstore covers Fulcio, WarpBuild covers Optimized runner infrastructure.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Sigstore and WarpBuild actually diverge.

Attributes where Sigstore and WarpBuild differ
AttributeSigstoreWarpBuild
Starting priceFreeOn request
Pricing modelOpen source, public instance free to useUsage-based per minute, varies by runner configuration
Free tierYesNo
PlatformsWeb, Linux, macOS, Windows, Self-hostedGitHub Actions, Linux, Windows, macOS, Cloud
CategoryCybersecurityDeveloper Tools

Identical on both: 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 Sigstore

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

Only in WarpBuild

  • Optimized runner infrastructure
  • Intelligent caching
  • Incremental builds
  • Multi-architecture support
  • Unlimited concurrency
  • Autoscaling
  • BYOC support
  • Docker builders

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 WarpBuild
  • Organisations meeting a signed-artifact requirement without buying a signing productnot WarpBuild
  • Publishing provenance that a consumer can verify independently of younot WarpBuild
  • Self-hosting the same components where a public log is unacceptablenot WarpBuild

WarpBuild

  • Accelerating CI builds for teams with high test volumesnot Sigstore
  • Running tests generated by AI coding assistants efficientlynot Sigstore
  • Reducing GitHub Actions costs by 50% or morenot Sigstore
  • Supporting teams that need ARM64 architecture runnersnot 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.

WarpBuild

  • Per-minute pricing requires tracking usage to estimate monthly costs
  • Large configuration runners (32 vCPU) expensive at $0.064/min
  • macOS M4 Pro 12-core at $0.16/min is highest-cost option
  • BYOC option requires cloud setup by customer

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

WarpBuild

On request
  • Linux x86-64 (2vCPU, 8GB)$0.004/minute
    • 2 vCPU
    • 8 GB RAM
    • Standard performance
  • Linux x86-64 (4vCPU, 16GB)$0.008/minute
    • 4 vCPU
    • 16 GB RAM
    • Increased performance
  • Linux x86-64 (8vCPU, 32GB)$0.016/minute
    • 8 vCPU
    • 32 GB RAM
    • High performance
  • Linux x86-64 (16vCPU, 64GB)$0.032/minute
    • 16 vCPU
    • 64 GB RAM
    • Enterprise performance

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 WarpBuild if

  • You need optimized runner infrastructure.
  • You work on GitHub Actions, Linux, Windows, macOS, Cloud.
  • You also want intelligent caching.
WarpBuild review

Questions people ask

Is Sigstore or WarpBuild better?
Neither clearly leads. Sigstore starts at Free and WarpBuild at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Sigstore or WarpBuild?
Sigstore has a free tier; the other does not. Paid plans start at Free for Sigstore and On request for WarpBuild.
Does Sigstore or WarpBuild run on more platforms?
Sigstore runs on Web, Linux, macOS, Windows, Self-hosted. WarpBuild runs on GitHub Actions, Linux, Windows, macOS, Cloud.
Can I use Sigstore for free?
Yes. Sigstore has a free tier, so you can try it without paying. WarpBuild starts at On request.
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 WarpBuild is typically brought in for.
What can Sigstore do that WarpBuild cannot?
Sigstore covers Fulcio, Rekor, Keyless signing, Multi-language clients. WarpBuild covers Optimized runner infrastructure, Intelligent caching, Incremental builds, Multi-architecture support.

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.

WarpBuild: How much cheaper is WarpBuild compared to GitHub Actions?

WarpBuild offers approximately 50% cost savings compared to GitHub-hosted runners. For example, Linux x86-64 2vCPU/8GB costs $0.004/min with WarpBuild vs $0.008/min with GitHub Actions.

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.

WarpBuild: What is BYOC and how does it differ from managed runners?

BYOC (Bring Your Own Cloud) allows customers to run WarpBuild on their own cloud infrastructure at $0.002/min. Managed runners use WarpBuild's cloud infrastructure. BYOC provides lower costs but requires customer setup.

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.

WarpBuild: Does WarpBuild support ARM64 runners?

Yes, WarpBuild offers ARM64 runners at lower costs than x86-64. Linux ARM64 starts at $0.003/min for 2vCPU/8GB configuration.

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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