Softwr

Cybersecurity · head to head

OWASP ZAP vs PartyKit

OWASP ZAP logo

OWASP ZAP

Cybersecurity

Free, open-source web application scanner and intercepting proxy, now governed by the Software Security Project.

From
Free
Free plan
Yes
Full reviewWebsite
P

PartyKit

Developer Tools

Platform for building and deploying realtime multiplayer servers on the edge

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: OWASP ZAP authenticated scanning of modern single-page applications is the hard part and ZAP makes you build it by hand: session handling, token refresh and login scripts are configured per application, and a misconfigured session means the scanner logs itself out and reports a clean result for pages it never reached.; PartyKit documentation and FAQ material on the marketing site is sparse compared to larger realtime platforms.
  • They diverge on capability: OWASP ZAP covers Intercepting proxy, PartyKit covers Stateful edge servers.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which OWASP ZAP and PartyKit actually diverge.

Attributes where OWASP ZAP and PartyKit differ
AttributeOWASP ZAPPartyKit
Pricing modelfreefreemium
PlatformsDesktop, Cli, Apiweb, api
CategoryCybersecurityDeveloper Tools
Founded2001Unknown

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 OWASP ZAP

  • Intercepting proxy
  • Passive scanner
  • Active scanner
  • AJAX spider
  • Automation Framework
  • Headless daemon and REST API
  • Docker images
  • Add-on marketplace

Only in PartyKit

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

What people use each for

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

OWASP ZAP

  • Adding a baseline security scan to every application's pipeline where per-target commercial licensing would limit coverage to a handfulnot PartyKit
  • Manual penetration testing that needs an intercepting proxy, request replay and fuzzing without a paid licence per testernot PartyKit
  • Teaching developers what an attack against their own endpoint looks like, using a tool they can install themselvesnot PartyKit
  • Pre-release regression scanning of an internal application that would never justify a commercial DAST subscriptionnot PartyKit

PartyKit

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

Where each one falls short

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

OWASP ZAP

  • Authenticated scanning of modern single-page applications is the hard part and ZAP makes you build it by hand: session handling, token refresh and login scripts are configured per application, and a misconfigured session means the scanner logs itself out and reports a clean result for pages it never reached.
  • There is no support contract in the product, so when a scan breaks the day before a release the escalation path is a GitHub issue and a community chat, which is not an answer that satisfies a delivery manager or an auditor who wants a named responsible party.
  • Active scanning sends genuine attack traffic, so it can create records, trigger emails, exhaust rate limits or destabilise a fragile environment, and pointing it at production without prior agreement produces an incident rather than a test result.
  • Output needs triage: passive rules generate large volumes of low-severity informational findings about headers and cookie flags that bury the few results that matter, and a team without someone tuning the rule set stops reading the report within a few sprints.
  • As a dynamic scanner it can only test what it can reach, so authorisation flaws between accounts, business logic abuse and anything behind an undiscovered endpoint go unreported, and a passing ZAP scan is evidence of nothing more than the absence of the classes of bug it looks for.

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.

Pricing, plan by plan

OWASP ZAP

Free
  • Free & Open SourceFree
    • Full functionality
    • Active & passive scanning
    • Spider

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

Which should you pick?

Choose OWASP ZAP if

  • You need intercepting proxy.
  • You want to start without paying.
  • You work on Desktop, Cli, Api.
  • You also want passive scanner.
OWASP ZAP review

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

Questions people ask

Is OWASP ZAP or PartyKit better?
Neither clearly leads. OWASP ZAP starts at Free and PartyKit at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, OWASP ZAP or PartyKit?
OWASP ZAP starts at Free and PartyKit at Free.
Does OWASP ZAP or PartyKit run on more platforms?
OWASP ZAP runs on Desktop, Cli, Api. PartyKit runs on web, api.
Can I use OWASP ZAP for free?
Both have a free tier, so you can try either at no cost before committing.
What is OWASP ZAP best used for?
OWASP ZAP is most often used for adding a baseline security scan to every application's pipeline where per-target commercial licensing would limit coverage to a handful, manual penetration testing that needs an intercepting proxy, request replay and fuzzing without a paid licence per tester, teaching developers what an attack against their own endpoint looks like, using a tool they can install themselves, pre-release regression scanning of an internal application that would never justify a commercial dast subscription. Of those, adding a baseline security scan to every application's pipeline where per-target commercial licensing would limit coverage to a handful and manual penetration testing that needs an intercepting proxy, request replay and fuzzing without a paid licence per tester are not what PartyKit is typically brought in for.
What can OWASP ZAP do that PartyKit cannot?
OWASP ZAP covers Intercepting proxy, Passive scanner, Active scanner, AJAX spider. PartyKit covers Stateful edge servers, WebSocket-first API, CRDT library compatibility, Framework integrations.

Answered from the vendors’ own pages

OWASP ZAP: Is it still called OWASP ZAP?

The project left OWASP in August 2024 and is now governed by the Software Security Project, with core development sponsored by Checkmarx. The tool is now just ZAP, though most existing documentation, courses and search results still use the OWASP name.

PartyKit: How much does PartyKit cost?

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

Source
OWASP ZAP: Is it free for commercial use?

Yes. It is Apache 2.0 licensed, with no per-application, per-scan or per-user cost, and it can be used and modified commercially without a licence agreement.

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
OWASP ZAP: Can it replace a penetration test?

No. It automates checks for known vulnerability classes against endpoints it can reach. It does not reason about business logic, chain findings into an attack, or test authorisation between accounts, which is most of what a tester actually does.

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
OWASP ZAP: Does it run in CI?

Yes, through the official Docker images and the Automation Framework, which defines scan jobs in YAML so configuration lives in the repository. A baseline passive scan is the usual starting point because it is fast and non-intrusive.

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
OWASP ZAP: How does it compare to Burp Suite?

Burp Suite Professional is the more polished manual testing tool and has a stronger scanner and extension ecosystem, but it is licensed per tester and Burp Suite Enterprise per target. ZAP is the better fit where cost per target is the binding constraint; many teams use both.

Share

Related pages

More on OWASP ZAP

More on PartyKit

Keep looking

Other head to heads