Free-tier api testing tools

JSONPlaceholder is a free fake REST API for testing and prototyping. It serves common resources such as posts, comments, albums, photos, todos, and users over standard HTTP endpoints, and supports GET, POST, PUT, PATCH, and DELETE requests.

CORS Tester

CORS Tester is a web-based tool for checking Cross-Origin Resource Sharing behavior against an API endpoint. It accepts an API URL, origin, HTTP method, optional credentials, custom headers, and request body, then returns preflight response headers and API server response headers for review.

Insomnia is an AI-native API collaboration platform for developers who design, test, debug, and manage endpoints across REST, GraphQL, gRPC, WebSocket, Socket.IO, and SSE workflows. It combines an API...

Pipedream Request Bin

Pipedream Request Bin provides a public URL for collecting HTTP requests and webhook payloads, then inspecting the incoming headers, body, and other request details in a human-friendly interface.

Beeceptor

Beeceptor is a mock API server platform for REST, SOAP, GraphQL, and gRPC endpoints. It lets developers upload OpenAPI, WSDL, GraphQL SDL, or proto definitions, or define responses through a no-code UI, then inspect requests, add matching rules, and return dynamic or stateful responses.

Postman

Postman is an API platform for designing, testing, documenting, monitoring, and distributing APIs and services. It includes an API client, collections and environments, specs, mock servers, Flows, CLI support, and workspace collaboration features.

Assertible

Assertible is a web service testing and monitoring platform for APIs and websites. It lets developers and QA teams create HTTP assertions, run post-deployment smoke tests, schedule uptime checks, and review detailed test results across environments such as staging and production.

Stoplight

Stoplight is an API design and documentation platform for creating OpenAPI and JSON Schema definitions, generating interactive documentation, and running mock servers from the same workspace. It supports code-based editing, schema reuse, design validation, Git sync, and OpenAPI export.

CurlHub.io

CurlHub is a no-install debugger for API requests. It lets developers inspect API traffic and create a simple request bin without installing local tooling.

Mockfly

Mockfly is a mock API generator that creates REST API endpoints for frontend development, API testing, and rapid prototyping. It supports generating fake JSON responses with Faker.js, AI-assisted JSON...

Mockaroo

Mockaroo is a random data generator and API mocking tool that produces test data in CSV, JSON, SQL, and Excel formats. It lets developers define schemas with fields such as names, email addresses, IP ...

mockapi.io

mockapi.io is a REST API mocking service that lets developers create endpoints, define resource schemas, generate custom data, and perform CRUD-style operations through a RESTful interface.

Tyk

Tyk is an API management platform and API gateway that supports REST, GraphQL, gRPC, and async APIs. It provides tools for API design, gateway enforcement, developer portals, analytics, security, governance, and deployment across cloud, hybrid, self-managed, and sovereign environments.

Apidog

Apidog is an all-in-one API platform for designing OpenAPI specifications, debugging requests against those specs, running automated API tests, publishing interactive documentation, and generating moc...

ngrok

ngrok is an all-in-one cloud networking platform that provides secure tunnels, API gateway routing, traffic policy, and observability for services running anywhere. It can expose localhost or private ...

Hoppscotch

Hoppscotch is a developer-first API platform for creating, testing, documenting, and sharing APIs. It is designed to help teams move from prototyping to production without switching tools, and it supports both cloud use and self-hosted deployment.