Apps similar to Roster HTTP Client include Bruno, which is open source with a free version. Other options are Postman, Insomnia REST Client, Yaak and ApiArk. There's no shortage of API Clients like Roster HTTP Client, with more than 25 alternatives for Mac, Linux, Windows, the web and Chrome OS.
Lightweight open source API client offering offline API testing, local filesystem storage via plain text, version control compatibility with git, intuitive request management, privacy-first design, cross-platform support, minimal resource usage, and community-driven development.
United States
Postman is a collaborative platform for API development that provides extensive tools for designing, testing, and documenting APIs. It allows API verification through requests, automated testing via Collection Runner, and offers both free and paid plans, catering to individuals and teams.
United States
A powerful REST API Client with cookie management, environment variables, code generation, and authentication for Mac, Window, and Linux.
United States
The API client for modern developers. Call REST, GraphQL, and gRPC APIs from a simple and intuitive app.
Canada
ApiArk is a local-first API client built with Tauri v2 and Rust. No login, no cloud, no telemetry. Supports REST, GraphQL, gRPC, WebSocket, SSE and MQTT from one interface. Collections are stored as plain YAML files on your filesystem, fully git-diffable.
Bosnia & Herzegovina
Insomnium is a fast local API testing tool that is privacy-focused and 100% local. For testing GraphQL, REST, WebSockets and gRPC. This is a fork of Kong/insomnia.
Free, open source, git-native API client. A local-first, account-free Postman alternative with a built-in MCP server, SOAP/GraphQL, request chaining and performance runs.
France
EU
Voiden.md is an offline-first, Git-native API workspace that unifies specs, docs, tests, and mocks using programmable Markdown blocks. Build APIs the way you actually work.
NetherlandsEU
HarborClient is a free, open-source desktop API client for macOS, Windows, and Linux. It gives you a familiar Postman-style workspace—collections, environments, request scripts, and a tabbed editor—while keeping your work on your machine or on storage you control.
United States
Cartero is a graphical HTTP client that can be used as a developer tool to test web APIs and perform all kind of HTTP requests to web servers. It is compatible with any REST, SOAP or XML-RPC API and it supports multiple request methods as well as attaching body payloads to...
SpainEU
Upcoming API testing tool in beta, built in GoLang, supporting HTTP/gRPC, workspaces, environments, request management, and various content types. Features include dark mode, local data storage, Postman import, environment variable setting, and request chaining.
Zaku is a native Rust, local-first, open-source API client engineered for speed and productivity.
