Alternatives / Retool
Looking for an open source Retool alternative? We compared 16 open source low-code builders, backends, and workflow tools by license, self-hosting, data sources, and AI features. Most build internal tools, some are databases or AI app builders, and several use restricted licenses or have stalled.
Written by Maxime DERAME
Last updated:
| Alternative | Best for | License |
|---|---|---|
| Appsmith | Closest low-code builder for internal tools | Apache-2.0 |
| ToolJet | Internal tools and dashboards (enterprise AI is paid) | AGPL-3.0 + enterprise features |
| Budibase | Business apps on your own data | GPL-3.0 + MPL-2.0 client libraries |
| Windmill | Scripts, workflows, and apps (partly proprietary) | AGPL-3.0 + Apache-2.0 + proprietary parts |
| Refine | React admin panels in code | MIT |
| Dify | AI apps and agents (restricted license) | Dify Open Source License (modified Apache 2.0) |
| NocoDB | Spreadsheet interface on databases (restricted license) | Sustainable Use License |
| NocoBase | CRM and ERP-style apps (restricted license) | NocoBase License (Apache-based) |
| Appwrite | Backend with auth and databases | BSD-3-Clause |
| Hatchet | Background jobs and agent orchestration | MIT |
| Evidence | SQL and Markdown reports | MIT |
| Mathesar | PostgreSQL spreadsheet interface | GPL-3.0 |
| Rowy | Spreadsheet UI for Firebase (development stalled) | Apache-2.0 |
| Open Mercato | Developer framework for CRM and ERP | MIT |
| undb | Archived: moved to Teable | AGPL-3.0 (archived) |
| Convertigo | Enterprise web and mobile apps | AGPL-3.0 (Community Edition) |
We looked for open-source tools that overlap with Retool's core: building internal tools, admin panels, and dashboards on top of databases and APIs. We verified each project's license, recent activity, stars, and self-hosting in its repository. Retool is a low-code platform, so the list mixes visual builders, code-first frameworks, backends, and workflow engines, and we flag restricted, archived, and stalled projects. See our methodology for the full criteria.
Appsmith, ToolJet, Budibase, and Convertigo are visual low-code builders. Refine is a React framework you code, and Windmill is code-first for scripts and workflows. NocoDB, NocoBase, Mathesar, Rowy, and undb are database or spreadsheet interfaces, Appwrite is a backend, Hatchet runs background jobs, Evidence builds reports, and Dify builds AI apps. Choose by what you need to build.
undb's repository is archived and says the project moved to Teable. Rowy's last commit was in November 2024, so it has stalled. NocoDB uses the Sustainable Use License, NocoBase uses its own NocoBase License, and Dify uses a modified Apache 2.0 license that restricts multi-tenant use and removing its logo, so these are source available rather than standard open source.
Appsmith and ToolJet are the closest: drag-and-drop builders for internal tools with many data source connectors and self-hosting. Budibase builds business apps on top of your data. Windmill is closest for developers who prefer scripts and workflows, but part of it is proprietary.
Appsmith is Apache-2.0, ToolJet is AGPL-3.0, and Budibase is GPL-3.0 with MPL-licensed client libraries. Refine, Hatchet, Evidence, and Open Mercato are MIT, Mathesar is GPL-3.0, Rowy is Apache-2.0, and Appwrite is BSD-3-Clause. Windmill's community edition combines AGPL-3.0 and Apache-2.0 code with proprietary parts, and Convertigo's Community Edition is AGPL-3.0-based.
Most projects had commits within days of this update. Refine's last commit was in September 2026, Rowy's in November 2024, and undb is archived.
Retool is a proprietary platform priced per user, with self-hosting limited to paid plans and a growing share of features reserved for higher tiers. Open-source alternatives let you self-host without per-user fees, connect any database or API, extend the code, and keep the apps you build, at the cost of running the platform and fewer ready-made enterprise features.
Dify is a visual platform for building AI agents, RAG pipelines, and LLM apps on one collaborative workspace, deployable in the cloud, in a VPC, or self-hosted. It is licensed under the Dify Open Source License, which is based on Apache 2.0 with additional conditions: you may not operate a multi-tenant environment without written authorization, and you may not remove or modify the logo and copyright information in its frontend. An enterprise edition adds SSO, RBAC, and support.
Pricing: Free to self-host within the license terms; cloud and enterprise plans are paid.
Airtable-style interface for existing PostgreSQL and MySQL databases, with multiple views, APIs, webhooks, collaboration, and schema management. Current releases use the Sustainable Use License, which adds restrictions beyond standard open-source licenses.
Pricing: Self-hosted and hosted options; check current terms and plan limits.
BSD-3-Clause application platform combining web hosting and serverless functions with databases, authentication, object storage, realtime APIs, messaging, and SDKs. It can be self-hosted with Docker or used as a managed cloud service; its role is broader and more backend-oriented than Vercel's frontend deployment focus.
Pricing: Open-source self-hosted platform and managed cloud service.
ToolJet is an AGPL-3.0 low-code platform for building internal tools, dashboards, and admin panels with a drag-and-drop builder, many data source connectors, and built-in AI features. An enterprise offering adds security and compliance features such as audit logs, advanced access control, and support SLAs.
Pricing: Free to self-host; cloud and enterprise plans are paid.
Appsmith is an Apache-2.0 low-code platform for building internal tools, admin panels, and dashboards with a drag-and-drop interface, many database and API integrations, and customizable workflows. It can be self-hosted or used in the Appsmith cloud, with paid plans for advanced and enterprise features.
Pricing: Free to self-host; cloud and enterprise plans are paid.
Refine is an MIT-licensed React meta-framework for building admin panels, internal tools, and data-heavy applications in code, with connectors for many backends and UI libraries. It requires coding in React, and its last commit was in September 2026.
Pricing: Free and open source; a paid enterprise offering exists.
Budibase is a low-code platform for building custom business web apps on top of your own data, with data integrations, automations, and self-hosting. The platform is licensed GPL-3.0 and its client and component libraries are MPL-2.0, so the apps you build are not themselves subject to the GPL. Paid cloud and enterprise plans add features.
Pricing: Free to self-host; cloud and enterprise plans are paid.
Build CRM, ERP, approval, and back-office applications using visual data modeling, workflows, permissions, plugins, and AI-assisted development. Its license adds restrictions to Apache-2.0.
Pricing: Self-hosted options; commercial licensing applies to restricted uses and features.
Windmill is a self-hosted platform for turning scripts into workflows and internal apps, with a code-first approach for TypeScript, Python, Go, and more. Its source is under AGPL-3.0 and Apache-2.0, but the community edition also includes proprietary parts. It is free to use internally, while commercial redistribution or managed services need a commercial license.
Pricing: Free to use internally; commercial redistribution and enterprise features need a paid license.
Hatchet is an MIT-licensed orchestration platform for running background tasks, durable workflows, and AI agents, with queues, scheduling, and observability. It is not a UI builder: it targets workflow and task execution for developers.
Pricing: Free to self-host; Hatchet Cloud is paid.
Evidence is an MIT analytics-as-code framework where developers and analysts create reports and interactive dashboards with SQL, Markdown, charts, tables, filters, maps, and reusable components.
Pricing: Free and open source under MIT; hosted deployment may be offered separately.
Apache-2.0 visual interface for Google Firestore with JavaScript and TypeScript Cloud Functions, backend workflows, role-based permissions, file uploads, APIs, and external connectors.
Pricing: Works with Firebase and Google Cloud in your own GCP project.
GPL-3.0 interface that works with normal PostgreSQL schemas, tables, relationships, roles, and permissions instead of introducing a proprietary data abstraction. Maintained by the nonprofit Mathesar Foundation.
Pricing: Free and open-source self-hosted project.
Archived AGPL-3.0 database and backend platform with grid, Kanban, gallery, and form views, type-safe APIs, and Docker deployment.
Pricing: Open-source and self-hosted; Docker deployment is available.
Open Mercato is an MIT-licensed foundation framework built on Next.js and TypeScript, with ready-made CRM and ERP domain modules for commerce, sales, order management, and encryption, spec-first development, and an AI-assisted workflow for developer teams. It is a framework for building a custom business application, not a hosted SaaS or an install-and-use ERP.
Pricing: Free and open source under MIT; you provide development and hosting.
Convertigo is a full-stack platform combining no-code and low-code studios to build web, mobile, and desktop business apps, with 300+ connectors. The Community Edition is AGPL-3.0-based, free for unlimited apps and on-premises install, while managed cloud, SLAs, offline data, and enterprise connectors are paid.
Pricing: Free Community Edition; managed cloud and enterprise features are paid.
| Alternative | Type | License | Self-hosted | Best for |
|---|---|---|---|---|
| Dify | AI app builder | Dify license (modified Apache 2.0) | Yes | AI apps |
| NocoDB | Database UI | Sustainable Use License | Yes | Spreadsheet views |
| Appwrite | Backend platform | BSD-3-Clause | Yes | Backend services |
| ToolJet | Low-code builder | AGPL-3.0 | Yes | Internal tools |
| Appsmith | Low-code builder | Apache-2.0 | Yes | Internal tools |
| Refine | React framework | MIT | Yes | Admin panels |
| Budibase | Low-code builder | GPL-3.0 + MPL client | Yes | Business apps |
| NocoBase | No-code platform | NocoBase License | Yes | CRM and ERP apps |
| Windmill | Scripts and workflows | AGPL-3.0 + proprietary parts | Yes | Workflows |
| Hatchet | Task orchestration | MIT | Yes | Background jobs |
| Evidence | Reporting | MIT | Yes | SQL reports |
| Mathesar | Database UI | GPL-3.0 | Yes | PostgreSQL |
| Rowy | Database UI | Apache-2.0 | Yes | Firebase data (stalled) |
| Open Mercato | Developer framework | MIT | Yes | CRM and ERP |
| undb | No-code database | AGPL-3.0 (archived) | Yes | Moved to Teable |
| Convertigo | Low-code platform | AGPL-3.0 (Community) | Yes | Enterprise apps |
Want the closest self-hosted internal tool builder
Appsmith is an Apache-2.0 low-code platform with drag-and-drop UI, many integrations, and cloud or self-hosted deployment.
Want internal tools with built-in AI and permissions
ToolJet builds internal tools and dashboards under AGPL-3.0, with enterprise AI and security features in paid editions.
Prefer code over drag and drop
Refine is an MIT React framework for admin panels and data-heavy apps, but you need to write React.
Want scripts, workflows, and apps together
Windmill combines scripts, workflows, and apps, but its community edition includes proprietary parts and limits commercial redistribution.
Want to build AI agents and LLM apps
Dify builds AI agents and RAG apps visually, under a modified Apache 2.0 license with multi-tenant and logo restrictions.
Want business apps on your own database
Budibase builds apps on top of your data, under GPL-3.0 with MPL-licensed client libraries.