10 Best API Testing Tools (2026)

Postman restricted its free plan to 1 user in March 2026. That single change sent shockwaves through the API testing market and created a genuine opening for alternatives. Developers are migrating in droves to tools that respect their wallets and their data.

I've tested all the major options. Here's what's actually worth using right now.

Quick comparison

1. Postman

Let's address the elephant in the room: Postman is still the most feature-rich API platform on the market. It's also no longer free for teams.

As of March 2026, the free plan is limited to 1 user with 25 collection runs and 50 AI credits per month. Want your teammate to access your workspace? That's $14/user/month (annual) minimum. The old Team plan was replaced by "Basic" at $14/user/month, and the new Professional tier runs $29/user/month.

What you get for the money is substantial: Postbot AI assistant (one-click test generation, debug assistance, response visualization), an AI Agent Builder for designing LLM-powered workflows, native Git integration, and the most mature mock server and monitoring infrastructure. Enterprise ($49/user/month) adds SSO, audit logs, and governance.

Best for: Companies that need the full API lifecycle -- design, test, mock, monitor, document -- in one platform and can afford the subscription.

Limitation: The free tier is now essentially a single-user demo. AI credits are metered and run out fast. And the pricing is 2-4x more expensive than alternatives that cover 80% of the same functionality.

2. Bruno

Bruno is the API testing tool I'd recommend to most developers in 2026. It stores collections as plain-text .bru files on your local filesystem. They live in Git alongside your code. No cloud sync, no account required for the open-source version, no vendor lock-in.

Version 3 (late 2025) added workspaces, YAML support, and a built-in terminal. The release cadence in 2026 has been monthly. You get REST, GraphQL, gRPC, WebSocket support, OAuth 2.0, scripting, test assertions, and code generation -- all in the free open-source version.

Pro ($6/user/month) adds native Git integration with visual diffs and merge conflict resolution. Ultimate ($11/user/month) adds unlimited workspaces, SSO, and audit logs.

Best for: Developers who believe API collections belong in version control, not on someone else's server.

Limitation: The Git-native approach means non-technical team members (PMs, QA without Git experience) will struggle. No cloud collaboration features in the free tier. The ecosystem of integrations is smaller than Postman's.

3. Insomnia

Insomnia had a rough 2023 when Kong required cloud accounts (later reversed). But Insomnia 12 (November 2025) was a genuine comeback. The app is fully open-source again under Apache 2.0, with a Git-native architecture that stores collections directly in repositories.

The free tier is generous: up to 3 users with unlimited Git sync, unlimited projects, unlimited collection runs, and 1,000 mock requests/month. Pro ($12/user/month) adds unlimited users and RBAC. Enterprise ($45/user/month) gets you SSO, vault integrations, and unlimited mocks.

Insomnia 12 also became the first major API client with native MCP client support -- connect to MCP servers, invoke tools, and inspect protocol messages. AI mock generation creates mocks from natural language descriptions.

Best for: Teams that want a polished GUI client with open-source transparency and Git-native workflows.

Limitation: The 2023 controversy lost Insomnia a lot of trust. The free tier's 3-user limit matters for larger teams. And the plugin ecosystem is smaller than Postman's.

4. Hoppscotch

Hoppscotch is the most accessible API testing tool available. Open your browser, go to the website, and start making requests. No download, no account, no setup.

It supports REST, GraphQL, WebSocket, MQTT, SSE, and Socket.IO. It has real-time collaboration, import from Postman/Insomnia, pre/post-request scripts, environment variables, and a CLI. The open-source version can be self-hosted. The Organization plan ($6/user/month) adds admin features and dedicated support.

With 50K+ GitHub stars and 750K+ developers, Hoppscotch is legitimate. It processes 5M+ requests monthly.

Best for: Quick API testing with zero friction. Great for onboarding new developers who shouldn't need to install anything.

Limitation: No native AI features. The web-based approach means you depend on browser capabilities. Advanced features (like complex auth flows) can be trickier than in desktop apps. Self-hosted enterprise pricing isn't transparent.

5. Apidog

Apidog is positioning itself as the direct Postman replacement, and its free tier tells you exactly why: 4 users with unlimited test runs, up to 5 projects, and full API design/mock/docs functionality. That 4-user free tier is the most generous team offering after Postman's restriction to 1.

Basic ($9/user/month) gives you 20 projects and more collaboration features. Professional ($18/user/month) goes unlimited. The platform covers API design, debugging, mocking, testing, and documentation in one tool.

Best for: Small teams looking for a Postman alternative with a generous free tier and all-in-one API development.

Limitation: Primarily strong in Asia-Pacific markets, with some English documentation gaps. No AI features yet (planned). Less mature ecosystem than Postman. The "all-in-one" approach means nothing is best-in-class.

6. Thunder Client

Thunder Client is a VS Code extension for API testing. If your workflow already lives in VS Code, this eliminates context-switching entirely.

The free tier covers basic testing (personal/non-commercial use). Starter ($3/user/month) adds 250 collection runs, WebSocket/SSE/gRPC, and CLI/CI/CD support. Business ($7/user/month) bumps to 500 runs. Enterprise ($16/user/month) goes unlimited with SSO and secrets management.

It also works in JetBrains IDEs now, which broadens its appeal.

Best for: Developers who live in VS Code and want API testing without switching apps.

Limitation: The free tier is limited to personal/non-commercial use. Feature depth doesn't match standalone tools like Postman or Bruno. The extension model means occasional VS Code version compatibility issues.

7. HTTPie

HTTPie is a love letter to the terminal. The CLI syntax (http GET httpie.io/hello) is so much more readable than curl that you'll never want to go back. The desktop and web apps are both free with no account needed.

Everything is free. The open-source CLI is BSD-3 licensed. AI features (preview) let you generate requests from natural language descriptions. HTTPie supports JSON natively, colorizes output by default, and handles sessions and auth seamlessly.

Best for: Developers who do most of their API testing from the command line.

Limitation: The desktop/web app is newer and less feature-rich than Postman or Bruno. No team collaboration features. The CLI is powerful but requires comfort with terminals.

8. SoapUI / ReadyAPI

SoapUI is the free, open-source option from SmartBear for SOAP and REST testing. ReadyAPI is the commercial enterprise version with a modular pricing model starting around $829/year for the Test module alone.

ReadyAPI added Smart Assertions in 2025 -- AI that analyzes API responses and automatically generates relevant assertions. The Performance module (from ~$6,449/year) supports load testing with up to 250 virtual users.

Best for: Enterprise teams with SOAP APIs or complex enterprise integration testing requirements.

Limitation: ReadyAPI is expensive -- a comprehensive setup can exceed $15,000/year per developer. The UI feels dated. SoapUI free is limited compared to modern alternatives.

9. Paw (RapidAPI for Mac)

Paw is a native macOS API client known for its polished, fast interface. It was acquired by RapidAPI in 2021. A one-time Classic license costs $49.99; Cloud plans start at $10/user/month.

The Mac-native experience is genuinely excellent -- fast startup, beautiful UI, great code generation. But it's been Mac-only for years despite promises of cross-platform support.

Best for: Mac developers who want a premium, native API client experience.

Limitation: Mac-only. The cross-platform expansion has been slow. The RapidAPI integration is optional but not particularly compelling.

10. Swagger / SwaggerHub

Swagger is primarily an API design and documentation ecosystem, not a testing tool. The open-source tools (Swagger Editor, Swagger UI, Swagger Codegen) are free. SwaggerHub is the commercial platform for team collaboration on API specs.

SwaggerHub pricing starts around $23/month for individuals and $35-85/user/month for teams. SmartBear rebranded it to "API Hub" in January 2025 and acquired Stoplight to bolster the platform.

Best for: Teams following a design-first API development approach who need collaborative spec editing and documentation.

Limitation: Not a testing tool in the traditional sense. Testing requires integration with ReadyAPI (separate product, separate cost). The pricing is opaque and varies by source.

How to choose

Individual developer, want free and powerful: Bruno (local-first, Git-native) or HTTPie (terminal-first). Both are free with no strings attached.

Small team (2-10), need collaboration: Hoppscotch (web-based, zero setup) or Apidog (4 free users). Insomnia if you want open-source with Git workflows.

Enterprise with compliance needs: Postman Professional/Enterprise or ReadyAPI. You're paying for governance, SSO, and audit logs.

VS Code-centric workflow: Thunder Client. No contest.

Migrating from Postman: Bruno or Insomnia. Both support importing Postman collections. Bruno is more radical (local-first); Insomnia is a gentler transition.

FAQ

Why did Postman restrict the free plan?
Postman is pushing hard into enterprise and AI features. Restricting the free tier to 1 user forces teams onto paid plans. The Basic plan at $14/user/month is how Postman monetizes the 30M+ developers on its platform.

Is Bruno really better than Postman?
For developers who work in Git, yes. Bruno's collections-as-code approach means your API tests live in your repo, get reviewed in PRs, and track with your code history. For non-technical users or enterprise governance, Postman is still stronger.

What's the deal with MCP support in API tools?
Model Context Protocol (MCP) lets AI agents interact with API tools programmatically. Insomnia 12 is the first major API client with native MCP support. This matters because AI agents increasingly need to test and interact with APIs as part of automated workflows.

Which free tool is closest to Postman?
Hoppscotch for web-based simplicity. Apidog for feature-breadth with 4 free users. Bruno for power users comfortable with Git.

Compare more developer tools in our software directory or check out API documentation tools for the docs side of the equation.