A local-first API client and HTTP interceptor for building, testing, and mocking APIs directly in your browser or desktop.
Requestly is a free and open-source tool that functions as both an API client and an HTTP interceptor. It allows developers to build, test, intercept, modify, and mock HTTP requests and responses, streamlining API development and frontend testing workflows. It solves the problem of fragmented tooling by combining client and interceptor capabilities into a single, local-first application.
Frontend and backend developers, QA engineers, and DevOps professionals who need to test, debug, and mock APIs during development or in CI/CD pipelines.
Developers choose Requestly for its local-first approach that prioritizes data privacy, its ability to replace multiple paid tools (like Postman and Charles Proxy), and its comprehensive feature set for API mocking and HTTP interception in one integrated solution.
Free and open-source API Client & Interceptor.
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Stores all API data directly on disk with Git integration, offering full privacy and ownership without mandatory cloud reliance, as highlighted in the Local Workspaces section.
Combines REST client, HTTP interceptor, and mocking in one application, reducing the need for separate tools like Postman and Charles Proxy for end-to-end API workflows.
Supports 1-click imports from popular tools such as Postman and Charles Proxy, easing transition with preserved configurations and reducing setup friction.
Enables local and cloud-based mocks with dynamic overrides using JavaScript, plus integration with e2e testing frameworks like Cypress and Playwright for CI pipelines.
The project is split across multiple repositories (browser extension, UI app, desktop app, etc.), complicating contributions and holistic understanding for developers.
Imports for tools like Insomnia and Bruno are marked 'Coming Soon' in the README, indicating gaps in migration support for users of those platforms.
Core HTTP interception features require installing Chrome/Firefox/Edge extensions, which may be blocked in locked-down corporate environments or introduce performance overhead.
Requestly is an open-source alternative to the following products:
Charles Proxy is the same as Charles, a web debugging proxy tool that captures and analyzes network traffic to help developers debug API calls, inspect requests, and test performance.
Insomnia is an open-source API client for designing, testing, and debugging REST, GraphQL, and other web APIs with a collaborative interface.
Postman is a collaboration platform for API development that allows developers to design, test, and document APIs.