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Developer Tools · head to head

Earthly vs Sigstore

Earthly logo

Earthly

Developer Tools

Engineering guardrails for the AI era

From
Free
Free plan
Yes
Full reviewWebsite
Sigstore logo

Sigstore

Cybersecurity

Free public signing and transparency infrastructure for open source artifacts

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Earthly pricing model not published; requires sales contact; 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.
  • They diverge on capability: Earthly covers Policy as code, Sigstore covers Fulcio.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Earthly and Sigstore actually diverge.

Attributes where Earthly and Sigstore differ
AttributeEarthlySigstore
Pricing modelNo pricing published on websiteOpen source, public instance free to use
PlatformsWeb, CLIWeb, Linux, macOS, Windows, Self-hosted
CategoryDeveloper ToolsCybersecurity
Founded2020Unknown

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 Earthly

  • Policy as code
  • Multi-stage enforcement
  • AI agent governance
  • Repository-wide policies
  • Incident response automation
  • Compliance management
  • Earthfiles build tool
  • Satellites

Only in Sigstore

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

What people use each for

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

Earthly

  • Enforcing engineering standards across AI and human developersnot Sigstore
  • Automating incident response procedures across all repositoriesnot Sigstore
  • Embedding compliance requirements into development workflowsnot Sigstore
  • Standardizing build processes with Earthfilesnot Sigstore

Sigstore

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

Where each one falls short

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

Earthly

  • Pricing model not published; requires sales contact
  • Earthly Lunar is a recent launch (2025) with limited track record
  • Primarily GitHub-focused; limited integration with other platforms
  • No public documentation on pricing or feature tiers

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.

Pricing, plan by plan

Earthly

Free

No published plan breakdown. See the Earthly review.

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

Which should you pick?

Choose Earthly if

  • You need policy as code.
  • You want to start without paying.
  • You work on Web, CLI.
  • You also want multi-stage enforcement.
Earthly review

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

Questions people ask

Is Earthly or Sigstore better?
Neither clearly leads. Earthly starts at Free and Sigstore at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Earthly or Sigstore?
Earthly starts at Free and Sigstore at Free.
Does Earthly or Sigstore run on more platforms?
Earthly runs on Web, CLI. Sigstore runs on Web, Linux, macOS, Windows, Self-hosted.
Can I use Earthly for free?
Both have a free tier, so you can try either at no cost before committing.
What is Earthly best used for?
Earthly is most often used for enforcing engineering standards across ai and human developers, automating incident response procedures across all repositories, embedding compliance requirements into development workflows, standardizing build processes with earthfiles. Of those, enforcing engineering standards across ai and human developers and automating incident response procedures across all repositories are not what Sigstore is typically brought in for.
What can Earthly do that Sigstore cannot?
Earthly covers Policy as code, Multi-stage enforcement, AI agent governance, Repository-wide policies. Sigstore covers Fulcio, Rekor, Keyless signing, Multi-language clients.

Answered from the vendors’ own pages

Earthly: What is the difference between Earthfiles and Earthly Lunar?

Earthfiles is an open-source build tool that reached 12,000 GitHub stars and is used by companies like NVIDIA, Intel, and Databricks. Earthly Lunar is a separate governance platform launched in 2025 for enforcing standards across development workflows.

Source
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.

Earthly: How does Earthly Lunar enforce standards?

Lunar converts engineering standards, compliance requirements, and processes documented in AGENTS.md files, wikis, and incident postmortems into enforceable guardrails that apply consistently across repositories and development stages.

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.

Earthly: What is the pricing for Earthly Lunar?

Pricing is not published on the website. Interested customers should contact Earthly's sales team for current pricing and feature tiers.

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.

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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