Windmill vs Prefect

Developer-led teams across languages. Engineers own the platform end-to-end: code in TypeScript, Python, Go, Bash, SQL and more, with Git, local dev, workspace forks, code review, CI/CD, AI coding tools and infrastructure as code.

TypeScript, Python, Go, Bash, SQL, PHP, Rust, C# and any Docker image, as first-class script languages with shared resources, auth and observability.

Each language is a native script primitive with its own UI, API and scheduler. No wrapping layer required to run a TypeScript script, a SQL query or a Bash command.

Build scripts in 20+ languages in a dedicated script editor. Each script is a standalone primitive with its own UI, API endpoint and scheduler; no Python wrapper required to run. Flows glue scripts together through a visual editor backed by YAML. Any public or private package is a first-class import with automatic dependency resolution.

Two ways to define workflows, one runtime under both. The visual flow builder produces JSON DAGs with multi-language steps, transparent data passing via results.step_name expressions, and built-in branches, loops, error handlers and approval steps. Workflow-as-code defines the same flow programmatically in Python or TypeScript.

In the workflow-as-code engine, two step primitives carry different cost profiles. task() dispatches a child job in a separate process and surfaces as its own job in the UI, for steps that need isolation or independent retries. step() runs inline in the same process and checkpoints its result to Postgres in roughly 0.5ms, for cheap units like a calculation, a CSV parse or a small DB query. Each step picks the cost it actually needs.

Run scripts locally with the Windmill CLI. VS Code extension, native language tooling (LSP, type-checking, linting) and AI coding tools (Claude Code, Codex).

Resources (typed JSON for credentials, connection info, configs) and Variables (individual secrets) are first-class and reusable across scripts, flows and apps. They're encrypted at rest, scoped via folders and groups for access control, and versioned in Git. External secret backends (Vault, AWS Secrets Manager) are Enterprise only.

Full IaC: scripts, flows, apps, resources, variables, secrets, schedules, folders, groups and permissions are all files in Git, deployed via the CLI and Git sync. Internal tooling runs like application code: PRs, reviews, rollbacks, CI/CD. Git sync is free for up to 2 users; beyond that is Enterprise only.

Any npm, PyPI, Go or Maven package is a first-class import with automatic per-script dependency resolution and lockfiles, and no plugin layer in between: you call the vendor's real SDK with full type inference and auto-completion in the editor. 50+ pre-built resource types cover common databases (Postgres, Snowflake, BigQuery), SaaS (Slack, Stripe, GitHub, Notion, OpenAI) and infrastructure (S3, Redis, Kafka): paste an API key into a typed form and the resource is shared across scripts, flows and apps, encrypted at rest. A community Hub has reusable scripts and flows for common tasks.

Native triggers for HTTP, cron, Kafka, NATS, Postgres CDC, SQS, MQTT, SMTP and WebSocket. Each trigger is a typed primitive in the UI: configure topic, subject or path, attach it to a script or flow, and Windmill handles the connection, replay and consumer-group state. Every script also gets an HTTP endpoint and a webhook URL for free, so most receive paths need zero glue code.

A new integration is a script with a new import: save and run, no restart, no image rebuild. The loop is hot-reload all the way through, in the web editor, the CLI and Git sync. Custom logic can be exposed as a typed script, packaged as a resource type for shared use, or published to the private workspace Hub for the team.

Paste a function body into the script editor, Windmill infers args, generates a UI, handles dependencies. No Python wrapper or decorator to learn. Triggers, schedules, variables and apps migrate one by one.

Step logic is already standard code (TS, Python, Go, Bash, SQL) that runs anywhere. The CLI exports the full workspace as plain files. What you lose leaving Windmill is the runtime, not the step code.

Real-time streaming logs, per-run inputs / outputs / duration, built-in worker queue metrics and a Prometheus exporter. Trace ID on every job.

Full trail of who ran / edited / deployed what. Extended retention is Enterprise only.

SOC 2 Type II compliant. RBAC, SSO (up to 10 users), encrypted secrets at rest and sandboxed script execution in open source. Uncapped SSO, audit logs and advanced access controls (SCIM, SAML) are Enterprise only.

Multiple isolated workspaces on the same instance, each with their own users, resources, secrets and access controls. Free tier is capped at 3 workspaces; unlimited is Enterprise only.

Workers poll Postgres directly with SELECT ... FOR UPDATE SKIP LOCKEDand self-schedule. No separate scheduler process, no broker, no extra polling intervals on the dispatch path.

Cold start is around 12ms on Bun and 26ms on Python per job. Dedicated-worker mode Enterprise only keeps the runtime and dependencies pre-warmed for 0ms cold start. Arguments pass directly between steps, results are checkpointed as JSONB in Postgres with no built-in size limit.

AGPLv3 core, free and unlimited self-hosted. Enterprise features (SSO, dedicated workers, audit logs, external secret backends) ship in a separate proprietary codebase. Managed cloud available.

Enterprise adds SSO, audit logs, dedicated workers, advanced worker groups. Public per-seat and per-worker pricing on the pricing page.