Floci is a local AWS emulator, open source and completely free. The highlights are no account needed, no authentication token required, no feature limitations — just run it with Docker (docker compose up) to get started.

Floci emerged as an alternative after LocalStack Community changed in March 2026 (requiring an auth token and stopping security updates). Compared to LocalStack, Floci is significantly lighter and faster:

• Startup time: ~24 ms (compared to ~3.3 seconds)

• Idle RAM: ~13 MiB (compared to ~143 MiB)

• Docker image: ~90 MB (compared to ~1 GB)

• License: MIT (free to use)

Floci supports 34 AWS services, including:

• Core: S3, SQS, SNS, DynamoDB, Lambda

• API: API Gateway (REST + HTTP)

• Auth: IAM, STS, Cognito

• Data/stream: Kinesis, DynamoDB Streams

• Infra: CloudFormation, ECS, EC2

• Other: KMS, EventBridge, RDS, ElastiCache, Athena (mock), Glue...

Some services run in-process (fast, lightweight), while services like Lambda, RDS, ECS will run using real Docker containers to mimic production closely (including IAM auth and SigV4).

For storage, Floci has 4 modes:

• memory: only RAM, data lost when shut down (fastest)

• persistent: saves to disk on shutdown

• hybrid (default): RAM + periodic flush

• wal: log writes first (safest)

Usage is very simple:

• Run the container → open http://localhost:4566

• Set AWS environment variables (can use fake values)

• Point SDK/CLI to the local endpoint → run like real AWS

Floci also has over 1,850 compatibility tests with many SDKs (Java, Node.js, Python, Go, Rust) and tools like AWS CLI, Terraform, CDK.

In summary, Floci is a powerful choice for developers:

• Extremely fast setup

• No constraints

• High performance

• Wide AWS coverage
  → Suitable for local development, testing, CI/CD without needing real AWS.