If you write or test APIs, you've probably got Postman open in a tab right now. It's the default choice — but it's also gotten heavier, more cloud-account-dependent, and more expensive as it's added AI features and team collections. None of that matters if all you need is to send a request and check the response. The good news: there's now a real spread of alternatives, from a free extension that lives inside your editor to AI agents that write your entire test suite for you. Here are five worth knowing about, all real products you can go sign up for today.
Thunder Client — for developers who live in VS Code
Thunder Client is a REST/WebSocket/gRPC client built directly into VS Code and JetBrains IDEs. No separate app to open, no account wall to get started — your requests live as local, git-syncable files right next to your code.
Price: the free tier covers core day-to-day API testing. Paid tiers (Starter $3, Business $7, Enterprise $16 per user/month, billed annually) add team collaboration features.
Good for: backend and API developers, or QA engineers, who don't want to leave their editor to fire off a request.
Limits: it's closed source, and paid plans are annual-billing only — no monthly option if you want to try a team tier without committing for a year.
Beak — for teams who want free and open source, full stop
Beak is a genuinely free, open-source Postman alternative that stores your API projects as plain files on disk instead of locking them behind a cloud account. Because those files are git-friendly, you get diffs and code review on your API collections the same way you'd review any other change.
Price: 100% free, no paid tier at all.
Good for: developers and small teams on macOS or Windows who want their API test setup to live in version control, not in someone else's cloud.
Limits: desktop-only (no web or mobile app), a small community (~24 GitHub stars at last check), and none of Postman's mock-server or public-collection features.
KushoAI — for turning existing specs into test suites automatically
KushoAI is an AI agent that reads your OpenAPI spec, Postman collection, or even a handful of cURL commands, and generates a complete test suite from it — including edge cases and security scenarios you might not think to write by hand.
Price: freemium, with a usable free tier; paid pricing isn't published, so you'll need to talk to sales for team use.
Good for: QA engineers and backend teams who already have documented APIs and want fast test coverage without writing it test-by-test.
Limits: it needs an existing API definition to work from, so it's less useful for undocumented or legacy APIs, and it's a newer entrant without Postman's track record.
Tusk Drift — for regression-testing based on real production traffic
Tusk Drift takes a different approach entirely: instead of writing tests, it records real production API traffic and turns it into a regression suite automatically, with built-in PII redaction so recorded traffic stays compliant.
Price: 14-day free trial (no card required), then $50/month per active developer on the Team plan; Enterprise is custom with a 200-seat minimum.
Good for: engineering teams shipping fast — especially ones using coding agents — who need to catch regressions without maintaining hand-written tests.
Limits: only Node.js and Python services are supported today, and at $50/developer/month it adds up fast for larger orgs. The Enterprise tier's 200-seat minimum also excludes smaller companies.
qAPI — for testing APIs with AI/LLM components
qAPI is a codeless API testing tool aimed at teams without a dedicated test-automation engineer — you click to set up tests rather than script them — and it's one of the few tools in this list with built-in evaluation for LLM/RAG systems (hallucination-rate checks included).
Price: SaaS cloud with a free trial; full pricing tiers aren't published.
Good for: QA teams testing REST/GraphQL/SOAP APIs that include AI-generated responses, where "does it return 200" isn't the only thing you need to check.
Limits: a much smaller ecosystem than Postman, no on-premise/self-hosted option mentioned, and pricing opacity makes it hard to budget for ahead of time.
| Tool | Best for | Price | Open source |
|---|---|---|---|
| Thunder Client | VS Code / JetBrains users | Free tier; $3-$16/user/mo | No |
| Beak | Git-native, zero-cost teams | 100% free | Yes |
| KushoAI | Auto-generating tests from specs | Freemium, custom paid | No |
| Tusk Drift | Regression tests from prod traffic | $50/dev/mo (Team) | No |
| qAPI | Testing LLM/RAG-backed APIs | Free trial, custom paid | No |
There's no single "best" Postman replacement here — the honest answer depends on what's actually costing you time today. If it's context-switching between your editor and a separate app, Thunder Client removes that friction for free. If it's principle — wanting your API tests versioned like the rest of your code instead of trapped in a vendor's cloud — Beak is the only fully open-source pick on this list. And if the real bottleneck is writing tests in the first place, KushoAI and Tusk Drift both automate that, just from different starting points (a spec you already have, versus traffic you're already generating). qAPI is the one to reach for specifically if your API has an LLM behind it and "the response looks plausible" isn't good enough anymore.