Best Contract Testing Tools in 2026
Updated
In short: Microcks is ranked #1 of 22 as of 4 October 2026, ahead of oasdiff and Pact. The best-ranked option with a free plan is oasdiff. The lowest first paid tier on this page is Specmatic at $0.83/mo.
If your services rely on API agreements, contract testing tools can help you check whether consumers and providers follow them. The 2026 ranking contains 22 entries, ordered from Microcks, oasdiff, and Karate at the top, with Specmatic and Pact Broker among the next options. Compared on AsyncAPI support, consumer verification, contract formats, contract registry, free plan, GraphQL support, paid from, provider verification, and self-hosted deployment, the tools offer several ways to assess fit. Start with the formats and APIs your team needs to cover, then consider which verification steps and registry capabilities matter. Hosting and pricing details can help narrow the options further.
22 contract testing tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
#1 Microcks Top pick · 7.3 Free plan · Free
#2 oasdiff Runner-up · 7.3 Free plan · $100/mo
#3 Pact Also great · 7.3 Free plan · $115.42/mo
- Free plan apiextensionLinuxmacOSself-hostedWebWindows
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms - Free planFree trial apiLinuxmacOSself-hostedWebWindows
- Free plan
- Yes
- Paid from
- 100 /mo
- Contract formats
- OpenAPI 3.0, OpenAPI 3.1, OpenAPI 3.2; JSON and YAML
RecognisedDocumentedFree planPlatforms$100/mofirst paid tier About oasdiffVisit site - Free planFree trial apiLinuxmacOSself-hostedWindows
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms$115.42/mofirst paid tier About PactVisit site - Free plan LinuxmacOSself-hostedWindows
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms$0.83/mofirst paid tier About SpecmaticVisit site - Free plan apiextensionLinuxmacOSself-hostedWindows
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms$8.33/mofirst paid tier About KarateVisit site - Free planFree trial apiLinuxself-hostedWeb
- Free plan
- Yes
- Contract formats
- Pact JSON (HTTP and message interactions)
- Consumer verification
- Yes
- Provider verification
- Yes
- Contract registry
- Yes
RecognisedDocumentedFree planPlatforms$115.42/mofirst paid tier About Pact BrokerVisit site - Free planFree trial apiLinuxWeb
- Free plan
- Yes
- Paid from
- 385 /mo
RecognisedDocumentedFree planPlatforms$385/mofirst paid tier About Confluent CloudVisit site - Free plan LinuxmacOSself-hostedWindows
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms - Free planFree trial apiself-hostedWeb
- Free plan
- Yes
- Contract formats
- GraphQL schemas in GraphQL SDL format
- Consumer verification
- Yes
- Provider verification
- Yes
- Contract registry
- No
RecognisedDocumentedFree planPlatforms$20/mofirst paid tier About GraphQL HiveVisit site - Free plan apiextensionWeb
- Free plan
- Yes
- Paid from
- 75 /mo
- Contract formats
- OpenAPI (JSON/YAML), GraphQL
- Consumer verification
- Yes
- Provider verification
- Yes
- Contract registry
- Yes
RecognisedDocumentedFree planPlatforms$89/mofirst paid tier About SpecShieldVisit site - Free planFree trial apiself-hostedWeb
- Free plan
- Yes
- Paid from
- 115.42 /mo
RecognisedDocumentedFree planPlatforms$115.42/mofirst paid tier About PactFlowVisit site - Free plan apiself-hosted
- Free plan
- Yes
- Contract formats
- Avro, JSON Schema, Protobuf
- Consumer verification
- No
- Provider verification
- No
- Contract registry
- Yes
RecognisedDocumentedFree planPlatforms - Web
- Contract formats
- OpenAPI, AsyncAPI, GraphQL, Apache Avro, Google Protobuf, JSON Schema, Kafka Connect, WSDL, XML Schema, ODCS v3.1
- Consumer verification
- Yes
- Contract registry
- Yes
RecognisedDocumentedFree planPlatforms - Web
- Free plan
- Yes
- Contract formats
- JSON, XML
- Provider verification
- Yes
RecognisedDocumentedFree planPlatforms - Web
- Contract formats
- OpenAPI
- Consumer verification
- Yes
- Provider verification
- Yes
- Contract registry
- Yes
RecognisedDocumentedFree planPlatforms - Web
- Contract formats
- OpenAPI, Pact
- Consumer verification
- Yes
- Provider verification
- Yes
- Contract registry
- Yes
RecognisedDocumentedFree planPlatforms - Web
- Free plan
- Yes
- Paid from
- 19 /mo
- Contract formats
- TypeScript, OpenAPI, JSON
RecognisedDocumentedFree planPlatforms -
- Free plan
- Yes
- Contract formats
- YAML, Groovy, Java, Kotlin
- Consumer verification
- Yes
- Provider verification
- Yes
- Contract registry
- Yes
RecognisedDocumentedFree planPlatforms -
- Free plan
- Yes
- Contract formats
- JavaScript
- Consumer verification
- Yes
RecognisedDocumentedFree planPlatforms -
- Contract formats
- ContractCase Case Files; JSON for HTTP contracts
- Consumer verification
- Yes
- Provider verification
- Yes
- Contract registry
- No
RecognisedDocumentedFree planPlatforms -
- Contract formats
- JSON
- Consumer verification
- Yes
- Provider verification
- Yes
RecognisedDocumentedFree planPlatforms -
- Free plan
- Yes
RecognisedDocumentedFree planPlatforms
Is your app on this list?
Numbered spots on this list can be sponsored. They are labelled, and the editorial order and scores never change for payment.
Questions about this list
Which contract testing tool is ranked first on Everything Xiaomi?
Microcks is ranked #1 of 22 with a score of 7.3. oasdiff is second and Pact third.
How many of these have a free plan?
12 of the 22 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Specmatic has the lowest first paid tier we found: $0.83/mo.
How is this list ranked?
Ranked on what each maker publishes: documentation depth, a free tier and the platforms it runs on. Paid placements never change a rank.