REST Assured vs Postman

Free and open source

From $14 per user/month (Basic, billed annually)

Free and open source. You pay in engineering time and CI minutes.

Free tier is generous for individuals. Costs come from collaborator seats and monitoring/mock-call volume, and enterprise plans jump sharply.

Everything, self-hosted

Free plan for individuals and small teams with limited collection runs, mock calls and monitors.

Widely used

OSS community · since 2010

Category standard

Postman, Inc. · since 2012

• API tests live in the codebase, versioned and reviewed with the service.
• Readable given/when/then chains that map directly onto HTTP semantics.
• Full access to Java for setup, data and assertions.

• Near-universal adoption — collections are a lingua franca between teams and vendors.
• Covers design, mocking, testing, documentation and monitoring in one place.
• Newman makes any collection runnable in CI without rewriting it.

• Java only, and requires developers rather than manual testers.
• No GUI, so exploratory request work needs a separate client.
• Verbose for very large payload assertions.

• Cloud-first sync raised real concerns for teams handling sensitive API credentials; the offline story has been repeatedly reduced.
• Collections stored in the vendor cloud rather than your repo make code review and branching awkward.
• The desktop app has grown heavy, and per-seat costs add up on large teams.

JVM teams that want API tests in the same repository as the service.

Teams that want one tool covering the whole API lifecycle and value ecosystem ubiquity.