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Cybersecurity · head to head

Sigstore vs Syft

Sigstore logo

Sigstore

Cybersecurity

Free public signing and transparency infrastructure for open source artifacts

From
Free
Rated
-
Full reviewWebsite
Syft logo

Syft

Cybersecurity

Generates a software bill of materials from images, filesystems and archives

From
Free
Rated
-
Full reviewWebsite

The short version

  • 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.; Syft lockfile parsing can drop packages silently. An open issue filed in August 2026 reports the yarn v1 cataloguer returning 118 of 745 packages with no error raised, which means a complete bill of materials and an 84 percent incomplete one look identical to the caller.
  • They diverge on capability: Sigstore covers Fulcio, Syft covers Multi-format output.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Sigstore and Syft actually diverge.

Attributes where Sigstore and Syft differ
AttributeSigstoreSyft
Pricing modelOpen source, public instance free to useOpen source, no licence fee
PlatformsWeb, Linux, macOS, Windows, Self-hostedmacOS, Linux, Windows, Docker

Identical on both: starting price (Free), free tier (Yes), 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 Sigstore

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

Only in Syft

  • Multi-format output
  • Broad ecosystem coverage
  • Binary classifiers
  • In-toto attestations
  • Library and CLI
  • Pairs with Grype

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

Syft

  • Producing a bill of materials for a customer or regulator that requires onenot Sigstore
  • Feeding an inventory into a vulnerability scanner rather than scanning images directlynot Sigstore
  • Recording what shipped in a build so a future disclosure can be answered quicklynot Sigstore
  • Public sector work where an SBOM is a contractual deliverablenot 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.

Syft

  • Lockfile parsing can drop packages silently. An open issue filed in August 2026 reports the yarn v1 cataloguer returning 118 of 745 packages with no error raised, which means a complete bill of materials and an 84 percent incomplete one look identical to the caller.
  • Fidelity varies sharply by ecosystem. Conan for C and C++, Haskell and Terraform get cataloguer support with no licence data, no dependency relationships and no file ownership, so a C and C++ shop gets the least from it.
  • Binary classification yields no licence or dependency metadata, and vendored or statically linked code is exactly where supply chain risk hides, so the blind spot and the risk overlap.
  • Incorrect CPE values and CPE collisions are recorded as open issues, and since Grype matches on CPE and PURL, an inventory error becomes a false negative in the security report downstream.
  • An inventory is not a risk assessment. Even a perfect bill of materials says a vulnerable version is present, never that the vulnerable function is called, and the triage burden lands entirely on the reader.

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

Syft

Free
  • SyftFree
    • Apache-2.0
    • No usage limits
    • Community support
  • Anchore Enterprise$undefined/year
    • Policy enforcement and reporting
    • Federal and commercial tiers
    • Pricing not published, quoted on request

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 Syft if

  • You need multi-format output.
  • You want to start without paying.
  • You work on macOS, Linux, Windows, Docker.
  • You also want broad ecosystem coverage.
Syft review

Questions people ask

Is Sigstore or Syft better?
Neither clearly leads. Sigstore starts at Free and Syft at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Sigstore or Syft?
Sigstore starts at Free and Syft at Free.
Does Sigstore or Syft run on more platforms?
Sigstore runs on Web, Linux, macOS, Windows, Self-hosted. Syft runs on macOS, Linux, Windows, Docker.
Can I use Sigstore for free?
Both have a free tier, so you can try either at no cost before committing.
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 Syft is typically brought in for.
What can Sigstore do that Syft cannot?
Sigstore covers Fulcio, Rekor, Keyless signing, Multi-language clients. Syft covers Multi-format output, Broad ecosystem coverage, Binary classifiers, In-toto attestations.

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.

Syft: Does Syft find vulnerabilities?

No. It produces an inventory. Grype, from the same company, matches that inventory against vulnerability feeds. They are separate tools and the distinction is frequently lost.

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.

Syft: Does anything in the Anchore stack do reachability analysis?

No. Neither Syft, Grype nor the commercial Anchore platform performs call graph or reachability analysis, so none of them tells you whether a vulnerable code path is actually invoked.

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.

Syft: Is it a CNCF or OpenSSF project?

No. It is single-vendor open source owned by Anchore, with no foundation governance. That is a different licence risk profile from Sigstore.

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.

Syft: What does Anchore Enterprise cost?

Not published. The pricing page is contact-sales only, with named but unpriced commercial and federal tiers.

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.

Syft: How do I know my SBOM is complete?

You largely cannot, which is the honest answer. Silent partial parsing is a known open defect, so a bill of materials used for compliance should be spot-checked against a known dependency list.

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