HTTP Toolkit

About

HTTP Toolkit is an open-source tool for debugging, testing, and building with HTTP on Windows, Linux, and Mac. It lets you capture HTTP(S) traffic with one-click interception for a wide range of tools and platforms, and you can target interception to a single client, such as an individual Android or iOS app, a browser window, a Docker container, or a backend process, without disrupting the rest of your computer. Clients can also be connected manually by configuring them to use HTTP Toolkit as an HTTP proxy.

Once traffic is captured, you can search, filter, and examine each message's URL, status, headers, and body, with parsed parameters and MDN documentation for standard headers. Message bodies can be highlighted and auto-formatted for formats such as JSON, Protobuf, Base64, HTML, XML, JavaScript, and hex. The tool also supports pausing live traffic with breakpoints to edit requests or responses, sending your own custom HTTP requests to explore APIs, and, in its Pro features, creating automated rewrite rules to inject mock responses, redirect requests to other servers, inject errors, and share rulesets with a team.