Best API Development tools

Designing, testing, documenting and mocking APIs.

26 tools ranked · updated 2026-08

1. Ranked 1

   86 — BenchRank score out of 100

   Postman

   Postman · API platform for designing, testing, monitoring and distributing APIs

   Best for: Development teams building, testing and managing APIs who want one tool from spec to monitoring.

   

2. Ranked 2

   84.8 — BenchRank score out of 100

   Scalar

   Scalar · API docs, SDKs, MCP servers and an API client from one OpenAPI file

   Best for: API teams that want docs, SDKs and MCP servers generated from one OpenAPI document

   

3. Ranked 3

   72.5 — BenchRank score out of 100

   Fern

   Fern · Docs, SDKs and a CLI generated from your API spec

   Best for: Teams with an OpenAPI-style spec who want hosted docs, generated SDKs and a CLI from one source

   

4. Ranked 4

   70 — BenchRank score out of 100

   WunderGraph

   WunderGraph · GraphQL Federation platform with an open-source, self-hosted router

   Best for: Platform teams running GraphQL Federation across many subgraphs who want a self-hosted router

   

5. Ranked 5

   68.5 — BenchRank score out of 100

   Fiddler

   Fiddler · Web debugging proxy for capturing and modifying HTTP traffic

   Best for: Developers and QA teams debugging HTTP/HTTPS traffic on Windows, macOS or Linux

   

6. Ranked 6

   66.3 — BenchRank score out of 100

   Insomnia

   Insomnia · Open-source API platform for design, debugging, testing and mocking

   Best for: API teams that need one tool to design, debug, test and mock APIs with local, Git or cloud storage

   

7. Ranked 7

   65.5 — BenchRank score out of 100

   Unkey

   UnKey · API deployment, gateway and observability on one platform

   Best for: Teams that want API deployment, key auth, rate limiting and logs from a single vendor

   

8. Ranked 8

   62.8 — BenchRank score out of 100

   Tyk

   Tyk · API management and AI agent governance on one control plane

   Best for: Teams running REST, GraphQL, gRPC and AI agent traffic that need self-hosted API management

   

9. Ranked 9

   62.6 — BenchRank score out of 100

   Voiden

   Voiden · Offline-first, Git-native API workspace built on plain Markdown

   Best for: Developers and teams who version-control everything and want API specs, docs and tests in Git

   

10. Ranked 10

    57 — BenchRank score out of 100

    Yaak

    Yaak · Local-first desktop API client for HTTP, GraphQL, gRPC and WebSocket

    Best for: Developers wanting an offline, local-first API client with Git-based sharing and a CLI for agents.

    

11. Ranked 11

    56.4 — BenchRank score out of 100

    Gravitee

    Gravitee · API, event and AI agent management on one platform

    Best for: Enterprises governing APIs, Kafka event streams and AI agent traffic on one platform

    

12. Ranked 12

    55 — BenchRank score out of 100

    KrakenD

    Krakend · Stateless open source API and AI gateway

    Best for: Teams running many microservices that need one gateway for routing, auth and AI traffic.

    

13. Ranked 13

    53.8 — BenchRank score out of 100

    ForgeCode

    Tailcall · Open-source coding harness that runs inside your ZSH terminal

    Best for: Developers who work in a ZSH terminal and want an open-source, model-agnostic coding agent.

    

14. Ranked 14

    51.5 — BenchRank score out of 100

    Optic

    Optic · Open-source CLI for OpenAPI linting, diffing and testing

    Best for: API teams on OpenAPI who want to catch breaking changes and keep specs matching real traffic

    

15. Ranked 15

    51.1 — BenchRank score out of 100

    Requestly

    Requestly · Git-native desktop API client storing collections as local JSON

    Best for: Development teams who want their API collections version-controlled in Git rather than a vendor cloud.

    

16. Ranked 16

    50.7 — BenchRank score out of 100

    Mockoon

    Mockoon · Local, open-source mock REST API servers with a cloud option

    Best for: Developers and small teams needing local mock REST APIs for development and integration testing

    

17. Ranked 17

    49.9 — BenchRank score out of 100

    Bruno

    Bruno · Git-native, local-first API client for REST, GraphQL, gRPC and WebSocket

    Best for: Development teams who want API collections version-controlled in Git rather than synced to a vendor cloud.

    

18. Ranked 18

    47.6 — BenchRank score out of 100

    Hive

    Hive · Open-source schema registry, analytics and gateway for GraphQL federation

    Best for: Teams running federated GraphQL APIs that want a self-hostable schema registry and gateway

    

19. Ranked 19

    45.2 — BenchRank score out of 100

    Hoppscotch

    Hoppscotch · Open-source API client for building, testing and sharing requests

    Best for: Developer teams wanting an open-source API client they can use on the cloud or self-host.

    

20. Ranked 20

    39.5 — BenchRank score out of 100

    Firecamp

    Firecamp · Open-source multi-protocol API client with shared team workspaces

    Best for: Dev teams testing REST, GraphQL, WebSocket and SocketIO APIs who want an open-source Postman alternative

    

21. Ranked 21

    36.7 — BenchRank score out of 100

    Dash for macOS

    Dash for macOS · Offline API documentation browser and snippet manager for macOS

    Best for: Mac developers who want offline API docs and reusable code snippets in one searchable app

    

22. Ranked 22

    29.6 — BenchRank score out of 100

    Charles

    Charles · HTTP proxy and monitor for viewing HTTP and HTTPS traffic

    Best for: Developers who need to inspect HTTP and HTTPS traffic between their machine and the internet

    

23. Ranked 23

    29.5 — BenchRank score out of 100

    HTTP Toolkit

    HTTP Toolkit · Open-source tool to intercept, inspect and edit HTTP(S) traffic

    Best for: Developers and testers who need to intercept, inspect and edit HTTP(S) traffic from specific clients.

    

24. Ranked 24

    29.3 — BenchRank score out of 100

    mitmproxy

    mitmproxy · Interactive HTTPS proxy for intercepting, inspecting and replaying traffic

    Best for: Developers and security testers who need to intercept, inspect and modify HTTPS traffic

    

25. Ranked 25

    22.9 — BenchRank score out of 100

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26. Ranked 26

    10.8 — BenchRank score out of 100

    HTTPie

    HTTPie · API testing client for the terminal, web and desktop

    Best for: Developers testing HTTP APIs who want a command-line client or a graphical app