Best Retool Alternatives in 2026 (Free & Open Source)
The best Retool alternatives in 2026 — free, open-source, and AI-native picks for internal tools, with feature and pricing trade-offs.
General
This post was written by an engineer at QueryPlane. QueryPlane is an app builder for your database: bring your own postgres db and you can create interactive applications to share with other developers, coworkers or even your customers. If you’re interested in trying it out, get started here.
Retool is the most widely used internal tool builder—connect your database, drag components onto a canvas, wire them to SQL queries, and ship an internal tool without building a traditional frontend. But Retool isn’t the right fit for every team. Some need open-source and self-hosting. Some want a simpler experience. Some want AI to handle the building. This post covers the best Retool alternatives.
In this post, we’ll cover:
- QueryPlane - AI-native app builder for databases (sign up)
- Retool - The market leader (for context)
- Appsmith - Open-source, self-hostable alternative
- ToolJet - Open-source with workflow automation
- Budibase - Open-source low-code platform
- Superblocks - Enterprise-focused alternative
- Windmill - Developer-first open-source platform
Retool (for context)
Retool pioneered the internal tool builder category. You connect data sources (PostgreSQL, MySQL, MongoDB, REST APIs, GraphQL, etc.), drag pre-built components (tables, forms, charts, buttons) onto a canvas, and wire them to queries. The component library is the largest in the category, and the platform supports complex workflows with event handling, state management, and custom JavaScript.
Retool offers cloud-hosted and self-hosted options. The free tier supports 5 users with unlimited apps. Paid plans start at $10/user/month (Standard). Business is $50/user/month with audit logs and SSO. Enterprise pricing is custom.
Why look for alternatives: Retool is closed-source, which means you can’t inspect or modify the code. Pricing scales with users, which gets expensive for larger teams. The learning curve is steeper than simpler tools—complex apps require understanding Retool’s event model, state management, and transformer system. And if you need to self-host, Retool’s self-hosted option is only available on paid plans.
Appsmith
Appsmith is the closest open-source alternative to Retool. The source code is available under the Apache 2.0 license, and the self-hosted Community Edition is free for unlimited users.
Appsmith provides a drag-and-drop builder with widgets for tables, forms, charts, modals, and containers. You connect data sources (PostgreSQL, MySQL, MongoDB, REST APIs, GraphQL, Google Sheets, and more), write queries, and bind widget properties to results using JavaScript expressions. The query editor shows results inline for fast iteration.
Appsmith supports multi-page applications with URL routing, Git-based version control, and granular access controls. The widget library covers the essentials, though it’s smaller and less polished than Retool’s.
Self-hosting the Community Edition is free for unlimited users. Appsmith Cloud is free for up to 5 users. The Business edition ($40/user/month) adds SAML SSO, audit logs, and custom branding.
Best for: Teams that need a Retool-like experience but require open-source and free self-hosting for compliance, security, or cost reasons.
ToolJet
ToolJet is an open-source internal tool builder (GitHub, AGPLv3) with a clean drag-and-drop interface. It connects to 50+ data sources including PostgreSQL, MySQL, MongoDB, REST APIs, GraphQL, Stripe, Slack, and more.
ToolJet’s differentiator is its workflow builder. You can automate multi-step processes: run a database query, check a condition, send a Slack notification, update a row in another database. This is useful for building approval pipelines, data processing workflows, or alerting systems on top of your internal tools.
The component library covers tables, forms, charts, modals, tabs, and other essentials. Each component can be styled and configured through a properties panel. ToolJet also supports custom components built with React.
Self-hosting is free for unlimited users. ToolJet Cloud has a free tier for 5 users, with paid plans starting at $20/user/month. Enterprise adds SSO, audit logs, and multi-environment support.
Best for: Teams that need workflow automation alongside their internal tools, and want an open-source option that’s more polished than Budibase.
See what QueryPlane can build for you
Connect to your database, write SQL with AI, and build shareable apps — all from your browser.
Budibase
Budibase is an open-source low-code platform (GitHub, GPLv3) that goes beyond internal tools into general application building.
Budibase’s differentiator is its built-in database. You can create tables directly in Budibase to store workflow state, user preferences, or metadata—without adding tables to your production database. This is useful when your internal tool needs to track things (approval status, assigned reviewer, internal notes) that don’t belong in the application database.
Budibase connects to external databases (PostgreSQL, MySQL, MongoDB, REST APIs) and provides both visual query building and raw SQL support. It includes automation workflows that trigger on database changes, schedules, or form submissions, then chain actions like sending emails, calling webhooks, or updating records.
The free tier supports 5 users on cloud, with unlimited self-hosted users. The Premium plan is $50/user/month for cloud.
Best for: Teams that need a built-in database for workflow state alongside external database connections, and value automation features.
Superblocks
Superblocks is an enterprise-focused internal tool builder that competes directly with Retool. It provides a drag-and-drop builder, connects to databases and APIs, and adds enterprise features like scheduled jobs, multi-step workflows, and a server-side execution model.
Superblocks differentiates with server-side application logic—queries and transformations run on Superblocks’ infrastructure (or your own via the on-premise agent), not in the browser. This is useful for security-sensitive environments where you don’t want database credentials or query results in client-side JavaScript.
Superblocks supports PostgreSQL, MySQL, MongoDB, Snowflake, BigQuery, REST APIs, GraphQL, and more. The platform includes a workflow builder for automating multi-step processes on a schedule or in response to events.
The free tier is available for small teams. Paid plans start at $50/user/month for Pro. Enterprise pricing is custom.
Best for: Enterprise teams that need server-side execution, scheduled jobs, and a Retool-like experience with stricter security requirements.
Windmill
Windmill is a developer-first open-source platform (GitHub, AGPLv3) for building internal tools, workflows, and scripts. Unlike the drag-and-drop builders above, Windmill is code-first—you write scripts in Python, TypeScript, Go, Bash, or SQL, and Windmill auto-generates UIs from the script parameters.
This approach appeals to engineering teams that prefer writing code over dragging components. You get version control, testing, and code review baked into the workflow. Windmill also provides a flow builder for orchestrating multi-step workflows with branching, retries, and approval steps.
Windmill is self-hostable for free with no user limits. The cloud-hosted option starts at $10/user/month. Enterprise pricing adds SSO, audit logs, and priority support.
Best for: Engineering teams that prefer code-first development and want an open-source platform for scripts, workflows, and auto-generated UIs rather than a drag-and-drop builder.
QueryPlane
QueryPlane takes a fundamentally different approach from every tool on this list. Instead of manually dragging components and wiring them to queries, you describe what you want to an AI agent, and it builds the application—writing the SQL, testing it against your database, and assembling the UI components into a working tool.
This changes the workflow from “build a tool” to “describe a tool.” You tell the agent: “build me an order management dashboard with a table of recent orders, a chart of daily revenue, and a form to update order status.” The agent writes the queries, tests them, and creates the application. For tools that would take an hour in Retool or Appsmith, QueryPlane produces them in a conversation.
QueryPlane connects to PostgreSQL, MySQL, MongoDB, Snowflake, BigQuery, Redshift, and other databases. Applications are shareable through role-based access controls.
Best for: Teams that want to go from “I need an internal tool” to “I have an internal tool” as fast as possible, using AI to handle the SQL and UI assembly.
Retool Alternatives Comparison
| Retool | Appsmith | ToolJet | Budibase | Superblocks | Windmill | QueryPlane | |
|---|---|---|---|---|---|---|---|
| Open source | No | Yes (Apache 2.0) | Yes (AGPLv3) | Yes (GPLv3) | No | Yes (AGPLv3) | No |
| Build approach | Drag-and-drop | Drag-and-drop | Drag-and-drop | Drag-and-drop | Drag-and-drop | Code-first | AI agent |
| Self-hosting | Paid only | Free | Free | Free | Agent-based | Free | No |
| Free tier | 5 users | 5 users | 5 users | 5 users | Yes | Unlimited (self-hosted) | Yes |
| Paid starting price | $10/user/mo | $40/user/mo | $20/user/mo | $50/user/mo | $50/user/mo | $10/user/mo | Paid |
| Workflow automation | Yes | Limited | Yes | Yes | Yes | Yes (flows) | Via AI agent |
| Component library | Largest | Large | Medium | Medium | Large | Auto-generated | AI-generated |
Exploring alternatives? See our detailed QueryPlane vs Retool comparison.
Frequently asked questions
What is the best free Retool alternative?
For free and open-source self-hosting, Appsmith and ToolJet are the strongest picks. Appsmith has a larger widget library and a more polished editor; ToolJet has stronger workflow automation. Both are free for unlimited self-hosted users. If you do not need self-hosting and want the fastest path to a working internal tool, QueryPlane has a free tier and uses AI to generate the SQL and UI.
Is Retool open source?
No. Retool is closed-source, and the self-hosted option is only available on the Business and Enterprise plans. If open source is a hard requirement, look at Appsmith (Apache 2.0), ToolJet (AGPLv3), Budibase (GPLv3), or Windmill (AGPLv3).
What is the cheapest Retool alternative for a 10-person team?
Retool’s Standard plan is $10/user/month, which is $100/month for 10 users — but most teams need the Business plan ($50/user/month, $500/month) for SSO and audit logs. Self-hosted Appsmith, ToolJet, Budibase, and Windmill are free regardless of team size, with infrastructure cost as the only line item. QueryPlane’s free tier covers small teams and its paid tier does not bill per workflow run or per AI action.
Which Retool alternative is best for AI-driven internal tools?
QueryPlane is built around an AI agent that generates SQL and assembles the UI from a natural-language description, so you describe the tool you want instead of dragging components. Retool added AI features later, on top of its component-based architecture. Other open-source alternatives have minimal native AI features today.
Which Retool alternative supports the most databases?
Retool, Appsmith, and ToolJet support 30+ data sources including PostgreSQL, MySQL, MongoDB, Snowflake, BigQuery, ClickHouse, REST, GraphQL, and many SaaS APIs. Budibase has fewer native connectors but supports REST. Windmill is code-first, so any database with a Python or TypeScript client is reachable. QueryPlane focuses on databases — Postgres, MySQL, Snowflake, BigQuery, Redshift, Databricks, ClickHouse, MongoDB, SQLite, and others — over generic API integrations.
Wrapping up
Retool remains the most mature platform with the largest component library and ecosystem. Appsmith is the best open-source Retool alternative for teams that need free self-hosting. ToolJet is a strong open-source option with better workflow automation than Appsmith. Superblocks targets enterprise teams with server-side execution and stricter security needs. Windmill appeals to engineering teams that prefer writing code over dragging components. And QueryPlane is the fastest path from “I need a tool” to “I have a tool”—the AI agent handles the SQL and UI assembly so you describe what you need instead of building it manually.