Best alternatives to Floci in 2026

Building software that uses cloud services like AWS Lambda or S3 usually means either paying for a real cloud account just to test your code, or juggling fake credentials and mock accounts to avoid a bill. Floci sidesteps both: it runs real, working versions of AWS, Azure and Google Cloud services directly on your own machine using Docker, with zero cloud account and zero credentials needed. Floci is a free, open-source (MIT) local cloud emulator supporting 68 AWS services, 22 Azure services and 22 GCP services, with genuinely functional execution engines rather than simple mocks — Lambda functions run in real Docker containers, RDS uses real PostgreSQL/MySQL, ElastiCache uses real Redis. It starts in about 24 milliseconds and uses roughly 13 MiB of idle memory, ships as a ~90 MB Docker image, and requires no auth tokens at all. It's explicitly positioned as the modern free alternative to LocalStack, after LocalStack moved parts of its own local emulator behind mandatory authentication in March 2026 — a shift Floci's maintainers call out directly as the reason the project exists.