Softwr

Developer Tools · head to head

PartyKit vs Sigstore

P

PartyKit

Developer Tools

Platform for building and deploying realtime multiplayer servers on the edge

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: PartyKit documentation and FAQ material on the marketing site is sparse compared to larger realtime platforms.; 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: PartyKit covers Stateful edge servers, Sigstore covers Fulcio.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which PartyKit and Sigstore actually diverge.

Attributes where PartyKit and Sigstore differ
AttributePartyKitSigstore
Pricing modelfreemiumOpen source, public instance free to use
Platformsweb, apiWeb, Linux, macOS, Windows, Self-hosted
CategoryDeveloper ToolsCybersecurity

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 PartyKit

  • Stateful edge servers
  • WebSocket-first API
  • CRDT library compatibility
  • Framework integrations
  • Global edge deployment
  • Custom domains

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.

PartyKit

  • Multiplayer collaborative appsnot Sigstore
  • Realtime AI agent backendsnot Sigstore
  • Live cursors and presencenot Sigstore
  • Collaborative whiteboards and documentsnot Sigstore

Sigstore

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

Where each one falls short

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

PartyKit

  • Documentation and FAQ material on the marketing site is sparse compared to larger realtime platforms.
  • Commercial free tier requires deploying to the user's own Cloudflare account, adding setup complexity.
  • Storage on the free Individual plan clears every 24 hours, limiting it to prototyping rather than persistent production data.
  • Smaller ecosystem and community than more established realtime infrastructure providers.

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

PartyKit

Free
  • IndividualFree
    • Up to 10 live projects
    • Deploy to the global edge platform
    • Storage clears every 24 hours
  • CommercialFree
    • Unlimited projects
    • Custom domains
    • Runs on your own Cloudflare account; pay only Cloudflare usage

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 PartyKit if

  • You need stateful edge servers.
  • You want to start without paying.
  • You work on web, api.
  • You also want websocket-first api.
PartyKit 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 PartyKit or Sigstore better?
Neither clearly leads. PartyKit 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, PartyKit or Sigstore?
PartyKit starts at Free and Sigstore at Free.
Does PartyKit or Sigstore run on more platforms?
PartyKit runs on web, api. Sigstore runs on Web, Linux, macOS, Windows, Self-hosted.
Can I use PartyKit for free?
Both have a free tier, so you can try either at no cost before committing.
What is PartyKit best used for?
PartyKit is most often used for multiplayer collaborative apps, realtime ai agent backends, live cursors and presence, collaborative whiteboards and documents. Of those, multiplayer collaborative apps and realtime ai agent backends are not what Sigstore is typically brought in for.
What can PartyKit do that Sigstore cannot?
PartyKit covers Stateful edge servers, WebSocket-first API, CRDT library compatibility, Framework integrations. Sigstore covers Fulcio, Rekor, Keyless signing, Multi-language clients.

Answered from the vendors’ own pages

PartyKit: How much does PartyKit cost?

PartyKit is completely free. Both the Individual and Commercial plans have no upfront costs.

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.

PartyKit: What is PartyKit's Individual plan?

The Individual plan is free and includes deployment to a global edge platform, support for up to 10 live projects, and is suitable for small projects. Storage is cleared every 24 hours.

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.

PartyKit: What is PartyKit's Commercial plan?

The Commercial plan is free but requires deploying to your own Cloudflare account. It includes custom domains, unlimited projects, and you pay only your Cloudflare usage costs.

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.

PartyKit: Can I upgrade from Individual to Commercial plan?

Yes, both plans are free but offer different feature sets. The Commercial plan removes project restrictions but requires managing your own Cloudflare infrastructure.

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.

Share

Related pages

More on PartyKit

More on Sigstore

Keep looking

Other head to heads