Mockoon vs Mockzilla

Mockoon is a free, open-source tool for designing and running mock APIs locally. It supports OpenAPI and can fit into existing applications and API design workflows. Mock behavior can use dynamic templating, rule matching, JSON databases, proxy mode, webhooks, and TLS. The tool can record requests and responses from a real API to create mocks, and it supports proxying and integration testing. The open-source version permits unlimited mock APIs and routes, including parallel runs. Its CLI can run mocks in headless automated environments such as CI, GitHub Actions, and Docker; mocks can also run in serverless environments including AWS Lambda and GCP/Firebase Functions. The desktop app stores mocks locally, works offline without an account, and reports that mock content and request data are not sent to Mockoon. Pro adds real-time team collaboration, synchronized mocks, and deployment management on private infrastructure; it can be self-hosted on-premises, in a private cloud, or on isolated or air-gapped networks. Team is listed at €10 a month, billed annually at €120/license/year, tax excluded. Eligible companies can request one 14-day self-hosted Pro trial with five license slots using a verified work email, without a payment method.

Mockzilla turns OpenAPI specifications or plain JSON files into hosted mock APIs for frontend work, integration tests, and demos. It generates responses from OpenAPI schemas and can validate requests against the specification. Users can inject latency or errors at service or endpoint level to exercise retry and fallback behavior. A proxy can forward requests to a real backend while supplying mock responses for routes that backend does not serve. Its GitHub Action creates a mock URL for each pull request, updates it on pushes, and cleans it up when the branch is gone. Mockzilla records request status and timing, and supports replaying individual requests or sets of requests. The CLI is MIT-licensed, works offline, and can run on a laptop or in CI; hosted cloud features are optional. The site also lists a GitHub Action and MCP server, with CLI setup instructions for Claude and Gemini. The Free plan is free, but API access is unavailable and request history lasts two hours. Hobby costs $10 a month. Uploaded content must not contain personally identifiable information, real financial data, health records, credentials, or other sensitive data.