Hoverfly vs LocalStack

Free and open source

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

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

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

Everything, self-hosted

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

Emerging

SpectoLabs · since 2016

Category standard

LocalStack · since 2017

• Capture mode produces a realistic simulation from live traffic with no authoring.
• Latency injection makes it useful for performance and resilience testing too.
• Small footprint — a single Go binary.

• 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.

• Smaller community and slower development than WireMock.
• Proxy configuration in complex networks takes effort.
• Captured simulations need periodic refresh.

• 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 needing lightweight service virtualisation against real recorded traffic.

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