01
Katalon
Katalon is an end-to-end AI testing platform designed for quality assurance teams. It unifies test automation, management, execution and production insights into one true platform.
98.0
Best API testing tools
10 ranked, with a plain verdict on every entry.
Katalon leads this ranking: it offers built-in AI agents that generate cases and heal locators automatically. Karate DSL is aimed at engineering teams modernising manual regression, and allows developers to write significantly less test code while running in any CI environment. Speedscale is aimed at engineering teams using AI coding agents, and mocks diverse dependencies like databases and gRPC at the protocol level.
RANKENTRYSCORETRENDFROM
2
Karate DSLKarate DSL is an open-source testing engine for API, UI and performance scenarios96.0NEW–
5
PostmanLets people and agents call APIs without holding secrets via Passport94.0NEW$14 per user/month
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The ranking, in detail
02
Karate DSL
Unified API, UI and AI test automation
Karate DSL is an open-source testing engine for API, UI and performance scenarios.
96.0
03
Speedscale
Validate AI code with real production traffic
Speedscale validates AI-generated code by replaying real production traffic against new changes. It captures application behaviour once to create a repeatable testing environment for development and CI.
96.0
04
vREST NG
Zero code API testing behind your firewall
vREST NG is a zero-code API test automation solution. It allows teams to create and run tests without scripting.
96.0
05
94.0
06
Apidog
All-in-one API platform: Design, debug, mock, test, and document
Apidog is an all-in-one API platform that enables teams to design, debug, mock, test, and document APIs within a single workspace. It replaces multiple disparate tools with one integrated solution for the entire API lifecycle.
92.0
07
Insomnia
An AI-native API collaboration platform with native Kong Konnect integration.
Insomnia is a collaborative API development platform supporting REST, GraphQL, gRPC, and WebSocket protocols. It enables developers to design, mock, test, and debug APIs with AI-native capabilities.
92.0
08
BrowserStack
Live browser testing and continuous testing platform
BrowserStack is a reliable platform for cross-browser and mobile app testing. It enables teams to test websites and apps on thousands of real devices.
90.0
09
StepCI
Automate API Testing & QA with open-source tools
Step CI is an open-source API testing framework. It enables engineers to automate API testing and quality assurance processes effectively.
90.0
10
Requestly
The Git-native API client for teams that design, build and test APIs at scale.
Requestly is an AI-first API platform designed for enterprises. It enables teams to manage, design and test APIs with collaboration, security and governance at every step.
86.0
Not on this ranking?
Positions 1, 2 and 3 are available to buy for twelve months.
Frequently asked questions
Who are these API testing tools built for?
Karate DSL says it is built for engineering teams modernising manual regression, and Speedscale for engineering teams using AI coding agents. vREST NG says it is built for QA teams requiring on-premise deployment, and Postman for teams building and shipping APIs together.
What should a buyer check before signing up?
Karate DSL states that the product requires a paid commercial licence for runtime execution of async protocol tests in CI/CD pipelines, and Speedscale that the free local version does not support Kubernetes or cloud collaboration features. Those are the limits each product publishes itself, not a full account of any plan.