WireMock vs Neosync

Free tier available

Free and open source

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

The MIT-licensed code remains free to self-host. The paid cloud service no longer exists — neosync.dev is offline.

Open-source WireMock is complete and free.

Everything, self-hosted

Category standard

WireMock Inc. · since 2013

Emerging

Nucleus Cloud (acquired by Grow Therapy) · since 2023

• 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.

• Open source and self-hostable, so sensitive data never leaves your infrastructure.
• Preserves referential integrity across tables.
• The last release is feature-complete for common Postgres and MySQL anonymisation work.

• 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.

• Archived and unmaintained since August 2025 — no security patches, no new connectors, no support.
• The hosted cloud has been shut down, so self-hosting is the only option.
• Fewer database connectors than the incumbents.

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

Realistically, nobody starting fresh. Existing self-hosted users can keep running it, but plan a migration to Tonic or a maintained alternative.