WireMock vs LocalStack

Free tier available

From $35 per user/month (indicative, Pro)

Open source is free; WireMock Cloud is a paid hosted service for shared team mocks.

Community edition is genuinely useful; Pro adds services such as RDS, ECS and advanced IAM enforcement.

Open-source WireMock is complete and free.

Community edition covers the most-used AWS services and is free.

Category standard

WireMock Inc. · since 2013

Category standard

LocalStack · since 2017

• Fault and latency injection lets you test the error paths that never occur on demand in a real sandbox.
• Record-and-replay produces a realistic mock from live traffic quickly.
• Runs anywhere: embedded, standalone, container or cloud.

• Integration tests against AWS services run offline in seconds at no cloud cost.
• Removes the shared-sandbox-account contention that plagues cloud teams.
• Works with Terraform and CDK, so infrastructure code is testable.

• Recorded stubs drift from the real service unless you re-record or verify contracts.
• Complex stateful scenarios get verbose in JSON.
• HTTP only — not for message queues or gRPC without extensions.

• Emulation is not identical to AWS; some behaviours and IAM semantics differ.
• Many services are Pro-only.
• Keeping up with AWS feature changes means occasional gaps.

Teams whose integration tests depend on third-party HTTP services.

AWS-native teams whose tests currently depend on a shared cloud account.