Best Open-Source Retool Alternatives (2026)
4 self-hostable, open-source projects that replace Retool — without per-user pricing that scales painfully. Each is scored for how hard it is to self-host, with one-click deploy options where they exist.
Retool's per-user pricing scales painfully once internal tools spread beyond a small team, and self-hosting the paid tiers still ties you to its licensing. Open-source builders give you the same drag-and-drop admin panels without per-seat costs and let you keep the apps and their data entirely on your own infrastructure.
Our picks at a glance
Difficulty 3/5 with the broadest deploy matrix (One-Click, Docker, Compose, Kubernetes, manual); all four options share the 3/5 floor.
Combines internal-app building, automations, and its own database, so you can ship tools without wiring up external storage first.
Offers official managed hosting alongside the widest self-host deploy options, making either route straightforward.
Compare all 4 alternatives
Tap a column header to sort| Project | Deploy | Managed | License | ||||
|---|---|---|---|---|---|---|---|
 Appsmith TypeScript | 37k ★ | 3/5 Moderate | One-Click Docker +3 | Apache-2.0 | 14 days ago | Repo | |
 ToolJet JavaScript | 35k ★ | 3/5 Moderate | One-Click Docker +3 | AGPL-3.0 | 14 days ago | Repo | |
 Budibase TypeScript | 25k ★ | 3/5 Moderate | One-Click Docker +3 | GPL-3.0 | 14 days ago | Repo | |
 Windmill Rust | 17k ★ | 3/5 Moderate | Docker Docker Compose +2 | AGPL-3.0 | 4 days ago | Repo |
What to look for: Check how well the builder connects to your existing databases and APIs, whether it ships a built-in datastore (Budibase does) or expects you to bring your own, and whether it leans visual (Appsmith, ToolJet, Budibase) or code-first (Windmill turns scripts into apps and workflows). Match the model to who's building: analysts want drag-and-drop, engineers may prefer Windmill's script-driven approach.
The alternatives, reviewed
- #1
AppsmithSelf-host: ModerateOpen-source low-code platform to build internal apps and admin panels fast
37k TypeScript Apache-2.0 14 days agoHow it compares to Retool
- Self-hosted stack is resource-heavy (MongoDB, Redis) and can be memory-hungry.
- Some advanced features (SSO, audit logs, custom branding) require a paid plan.
- Editor can feel sluggish on very large or complex apps.
- Mobile/responsive layout support is weaker than desktop app building.
- #2
ToolJetSelf-host: ModerateOpen-source low-code platform for building internal tools and dashboards
35k JavaScript AGPL-3.0 14 days agoHow it compares to Retool
- Some enterprise features (SSO, audit logs, advanced RBAC) are paid-only.
- Fewer polished, battle-tested connectors than Retool's large catalog.
- Complex apps can hit performance and editor-ergonomics limits.
- Documentation gaps around advanced/custom component scenarios.
- #3
BudibaseSelf-host: ModerateOpen-source low-code platform for internal apps, automations, and its own database
25k TypeScript GPL-3.0 14 days agoHow it compares to Retool
- Some enterprise features (SSO, enforced RBAC, audit) are behind paid Business Source License tiers.
- Built-in database is more limited than a dedicated Airtable for complex relations.
- Fewer connectors and a smaller ecosystem than Retool.
- Custom-component and theming flexibility is more constrained than hand-built apps.
- #4
WindmillSelf-host: ModerateDeveloper platform to turn scripts into workflows and internal apps
17k Rust AGPL-3.0 4 days agoHow it compares to Retool
- Code-first approach is more developer-oriented than Zapier's pure no-code experience.
- AGPL plus a separate enterprise edition; some features (distributed workers at scale, SSO, audit) are gated.
- Fewer turnkey SaaS connectors; you often write the integration glue yourself.
- Self-hosting requires Postgres and worker configuration for real workloads.
The verdict
Appsmith is the strongest all-around Retool replacement: most active, widest deploy options, Apache-2.0 licensed, and available as managed hosting. Choose Budibase if you want a built-in database and automations in one package, or Windmill if your team prefers turning scripts into tools over a pure visual builder.
Retool alternatives — frequently asked questions
What is the best open-source Retool alternative?
Appsmith is the most popular and well-rounded (~37k stars, Apache-2.0, broad deploy options). ToolJet and Budibase are close competitors, and Windmill is the pick for script-driven, developer-first internal tools.
Which Retool alternative is easiest to self-host?
All four (Appsmith, ToolJet, Budibase, Windmill) are rated 3/5. Appsmith, ToolJet and Budibase each offer a One-Click deploy in addition to Docker and Kubernetes, so they're the quickest to stand up.
Can I avoid Retool's per-user pricing?
Yes. Self-hosting any of Appsmith, ToolJet, Budibase or Windmill removes per-seat licensing entirely; you pay only for the infrastructure you run them on.
Which one includes its own database?
Budibase ships with its own built-in database alongside the app builder. Appsmith, ToolJet and Windmill connect to your existing databases and APIs instead.
Is there a more code-first option than the visual builders?
Windmill turns scripts into workflows and internal apps, making it the most developer/code-centric choice. It's written in Rust and licensed AGPL-3.0.
Do these offer managed hosting like Retool Cloud?
Yes. Appsmith, ToolJet, Budibase and Windmill all provide an official managed/cloud option, so you can move off Retool without self-hosting if you prefer.