API testing and mocking tools sit in an interesting place in the developer toolchain – they’re used constantly but rarely given much thought until Postman announces another pricing change or forces everyone to create an account. The alternatives have grown considerably more capable in the past two years. Some are lightweight replacements that do 90% of what Postman does with none of the bloat. Others take a different approach entirely – file-based, version-control-friendly, terminal-native. And increasingly, AI-assisted request building is appearing across the category.
This guide covers the best HTTP testing and API tooling for developers in 2026, from full Postman alternatives to the tools that approach the problem differently.
Bruno
Bruno has become the Postman alternative of choice for developers who want their API collections version-controlled properly. The core design decision is simple but significant: Bruno stores your collections as plain text files on your filesystem (in its own .bru format) rather than in a proprietary cloud database. You commit them to Git alongside your code. Team members pull them. Diffs are readable. There’s no sync account, no cloud dependency, no subscription required for the basic workflow.
The editor itself is clean and fast – Bruno is an Electron app but a well-optimised one. You get environment variables, pre-request scripts in JavaScript, response assertions, and request chaining. The collection runner lets you execute a sequence of requests in order, which covers most CI integration use cases. The Secret feature lets you mark variables as sensitive so they’re excluded from the plain-text files while still being usable in requests.
Bruno can import existing Postman and Insomnia collections, which makes migration realistic. The open-source core is MIT licensed; Bruno’s commercial offering adds LDAP/SAML, audit logs, and priority support for enterprise teams.
macOS, Windows, Linux. Core features free and open source.
Best for: Developers and teams who want API collections version-controlled in Git and are done with Postman’s cloud sync requirements.
Hoppscotch
Hoppscotch is an open-source, browser-based API client that covers REST, GraphQL, WebSocket, Server-Sent Events, MQTT, and Socket.IO from a single interface. Running it as a Progressive Web App or via desktop app gives you offline access; the self-hosted option (Docker) lets you run it on your own infrastructure for teams with data residency requirements.
Where Hoppscotch stands out is protocol breadth. If you’re testing WebSocket connections, real-time SSE streams, or MQTT message brokers alongside standard REST endpoints, having everything in one tool saves constant context switching. The UI is modern and fast, environment management works well across teams using the cloud sync, and the collections format is exportable.
Hoppscotch Cloud has a generous free tier; self-hosting the Community Edition is completely free. The Litestream-backed persistence in the self-hosted version is solid. For teams who want a Postman replacement they can run on their own servers, it’s the strongest option in the category.
Best for: Developers working with multiple API protocols beyond REST, and teams who want a self-hostable open-source alternative to Postman.
Thunder Client (VS Code)
Thunder Client is a VS Code extension that brings a full-featured REST client into your editor. If you’re already in VS Code and want to test API endpoints without switching to a separate application, Thunder Client is the answer – the context switch cost goes to zero and you’re using the same window you’re coding in.
The feature set covers the majority of what developers need from a daily-driver API tool: collections, environment variables, request chaining, response assertions, and a collection runner. The Git sync feature stores collections as JSON files in your project – similar in philosophy to Bruno, though the format is less human-readable. The AI Assistant (available in Thunder Client Pro) generates requests from natural language descriptions and suggests test cases based on the response schema.
Thunder Client Free covers core features. Pro is $9/month and adds AI features, advanced scripting, and team sync. It works in Cursor and Windsurf too, which makes it a natural choice if you’re in an AI-native editor already.
Best for: Developers who want to stay in VS Code (or a VS Code fork) for everything and don’t want to manage a separate API client application.
HTTPie
HTTPie has existed as a command-line HTTP client for years – the more human-friendly alternative to curl, with coloured and formatted output, JSON by default, and a syntax that doesn’t require remembering a dozen flags. In recent years it has gained a desktop and web application alongside the CLI, making it a multi-surface tool.
The CLI remains the strongest part. http GET api.example.com/users Authorization:"Bearer token" is considerably more readable than the curl equivalent, and for developers who live in the terminal it integrates naturally into scripts. The desktop app is cleaner than most Electron alternatives and syncs with the HTTPie cloud for collections and environments.
The CLI is open source and free. HTTPie Desktop and cloud sync are on a freemium model.
Best for: Terminal-first developers who want a readable curl replacement for quick API testing, with the option to use a GUI for more complex workflows.
.http and .rest Files (VS Code + JetBrains)
Worth mentioning as an approach rather than a product: both VS Code (via the REST Client extension) and all JetBrains IDEs (built-in HTTP client) support .http files – plain text files containing HTTP requests in a standard format that can be version-controlled, shared, and executed directly in the editor.
A .http file for a typical REST API looks like this:
### Get all users
GET https://api.example.com/users
Authorization: Bearer {{token}}
Content-Type: application/json
### Create a user
POST https://api.example.com/users
Content-Type: application/json
{
"name": "Jonathan",
"email": "jonathan@example.com"
}You click the run button (or use a keyboard shortcut) and the response appears inline. Variables come from environment files. The whole collection is a text file in your repository. No application to install, no account to create, no format to migrate between tools. For teams that use JetBrains IDEs, the built-in HTTP client is a compelling zero-friction option that’s easy to overlook.
Best for: Teams using JetBrains IDEs who want version-controlled API requests without any additional tooling overhead.
How to Choose
If you want the cleanest Postman replacement with proper Git-based collection storage, Bruno is the most direct path and handles migration from existing Postman collections.
If you need multi-protocol support (WebSocket, MQTT, SSE) or want a self-hostable team solution, Hoppscotch is the strongest open-source option.
If you’re in VS Code all day and don’t want to switch windows, Thunder Client keeps everything in one place.
If you’re terminal-first and want something readable and scriptable, HTTPie‘s CLI is the tool you want.
And if your team is on JetBrains IDEs already, the built-in .http file support is the zero-overhead option that’s already installed – give it a try before adding another tool to the mix.
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