10 top low code app builders open source and self-hosted in 2025

Are you looking to create your own app without the need for extensive coding knowledge?

In 2025, the you can use open source or self hosted low-code app builder scene is booming with innovative options for all skill levels.

Quick recap of best low code tools

• UI Bakery – Best for building secure, enterprise-grade internal tools with fine-grained access control.
• ToolJet – Best for open-source teams needing complex internal UI components with React/JS/Python logic.
• Superblocks – Best for engineers building automation-heavy, backend-driven internal tools with cloud integrations.
• Appian – Best for enterprises prioritizing compliance, process automation, and robust governance.
• FlutterFlow – Best for startups and agencies creating cross-platform mobile/web apps using Flutter.
• Retool – Best for developers who need full control over internal apps and quick database/API integrations.
• Appsmith – Best open-source solution for building customizable internal dashboards and admin tools.
• OutSystems – Best for large enterprises modernizing legacy systems and needing full-stack, scalable solutions.
• Mendix – Best for enterprise teams seeking a balance of no-code simplicity and pro-code power.
• Budibase – Best for self-hosted internal tools that connect spreadsheets, databases, and APIs.

What are low code tools?

Low-code tools are platforms that simplify software development by allowing users to build applications with minimal coding. These tools use visual interfaces, drag-and-drop components, and pre-built logic to streamline the creation of everything from simple forms to complex enterprise systems. Often grouped with no-code platforms, low code no code tools empower both professional developers and non-technical users to launch solutions faster.

Whether you're building internal tools, dashboards, mobile apps, or full-scale web apps, low code development tools help reduce development time, minimize bugs, and significantly cut costs. Many of the best low code tools also integrate with modern databases, APIs, and third-party services, enabling seamless automation and data flows.

As AI becomes more integrated into development, we're seeing a new wave of low code AI tools that generate code snippets, auto-suggest UI logic, and even build full apps based on prompts. These tools are especially powerful for teams needing rapid prototypes or internal solutions without committing to traditional, time-consuming dev cycles.

For web projects in particular, low code web development tools offer responsive design systems, built-in hosting, and deployment options – ideal for startups, agencies, and enterprise teams alike.

UI Bakery

UI Bakery is an advanced low-code development platform purpose-built for creating secure, scalable internal tools and admin dashboards – especially for enterprise teams. The tool comes with 100 UI custom components, granular permissions, and powerful integrations, UI Bakery empowers developers to rapidly build business-critical apps while maintaining full control over logic, security, and data access.

Built by engineers for engineers, UI Bakery acts as a visual app building backed by JavaScript and SQL customization, making it a perfect fit for teams that need speed without sacrificing flexibility. Its enterprise-ready features include RBAC, audit logs, SOC 2 compliance, SSO/SAML, and deployment options to private cloud or on-premise environments.

UI Bakery excels in scenarios where security, performance, and fine-grained access control matter. From data dashboards and customer portals to internal admin panels, it helps enterprises eliminate repetitive front-end work while preserving code quality and scalability.

UI Bakery features:

• Low-code internal tool builder for enterprises
• Drag-and-drop UI components
• JavaScript logic editor and SQL support
• RBAC (role-based access control)
• SSO/SAML authentication
• Audit logs and activity tracking
• REST, GraphQL, PostgreSQL, MongoDB, and Firebase integrations
• Self-hosted & on-premise deployment
• SOC 2 compliant
• Custom branding and white-labeling

UI Bakery limitations:

• Not open-source
• Primarily focused on internal tools (not for public apps)
• Some learning curve for complex business logic

UI Bakery pricing

• Free: $0
• Paid plans start from $9 per developer/month
• Custom pricing for enterprises by request

UI Bakery ratings and reviews

• G2: 4.7/5 (74 reviews)
• Capterra: 4.8/5 (10+ reviews)

ToolJet

ToolJet is a multifunctional open source low code platform which gives users a capability to produce interface components that are complex and flexible even without specialized developers. It has the features of smooth integrations, a flexible and drag-and-drop database, and the functionality to perform both routine & complex business operations, ToolJet brings the comfort of building custom internal tools.

The developers can implement JavaScript and Python for the customized logic and data transformation and reuse the React components with ease in addition to that. Security, scalability and multi-environment support are a few of the more enhanced features of ToolJet for enterprises. These ensure that the enterprise has a secure and scalable low-code solution for its critical applications.

ToolJet features

• Integrations
• Lightning Fast Development
• Connect effortlessly to your data sources
• Build scalable databases
• Automate Workflows
• Supports JavaScript & Python
• Import React components
• Secure and Scalable Low-Code Solution for Enterprises

ToolJet Limitations

• Lack of information on security features
• Limited support for advanced data transformations
• Potential learning curve for users unfamiliar with low-code platforms

ToolJet pricing

• Free: $0
• Paid plans start from $79 per builder/month
• Custom pricing for enterprises by request

ToolJet ratings and reviews

• G2: 4.8/5 (36 reviews)

Superblocks

Superblocks is a modern low-code platform designed specifically for engineers building powerful internal tools. It focuses on backend logic, frontend UI, and automation — all within a developer-friendly environment. With Superblocks, teams can write custom SQL, Python, and JavaScript, while visually orchestrating business workflows and deploying them securely to production.

Built for scale, Superblocks offers enterprise-grade features like RBAC, audit logs, environment isolation, and SSO/SAML. Its native integrations with databases, APIs, and cloud services like AWS and Snowflake make it ideal for modern enterprise stacks.

Superblocks also supports AI-based development, allowing teams to leverage low code AI tools for auto-generating queries or code blocks. It's a compelling alternative to traditional low code web development tools, especially for companies that prioritize developer control and speed.

Superblocks features

• Developer-first low-code platform
• Write SQL, Python, JavaScript in logic blocks
• Drag-and-drop UI builder
• Native integration with REST, GraphQL, and cloud services
• Scheduled jobs and automation workflows
• RBAC and SSO/SAML
• Audit logs and environment control
• Deploy to cloud or on-prem
• AI-powered code generation (beta)

Superblocks limitations

• Not open-source
• Primarily focused on internal tools
• Limited community resources compared to older platforms

Superblocks pricing

• Available per request

Superblocks ratings and reviews

• G2: 4.7/5 (190+ reviews)

Appian

Appian is one of the most established low-code platforms in the enterprise space, known for enabling large organizations to build secure, mission-critical apps at scale. With a strong focus on process automation, case management, and enterprise workflows, Appian empowers cross-functional teams to deliver applications quickly while meeting strict compliance and governance standards.

The platform combines visual development with AI, RPA (robotic process automation), and data fabric technologies, helping enterprises unify data and automate operations across systems. Appian also supports mobile-first development, DevOps pipelines, and real-time monitoring – all under a unified low-code experience.

Appian’s architecture is cloud-native but also supports on-premise and hybrid deployment, making it suitable for finance, healthcare, government, and other regulated industries.

Appian features

• Enterprise-grade low-code application platform
• Visual workflow and process builder
• AI, RPA, and data fabric capabilities
• Case and task management
• Mobile-first and responsive design
• Role-based security and access control
• Compliance-focused (HIPAA, FedRAMP, etc.)
• Cloud, on-premise, and hybrid deployment
• Advanced analytics and monitoring tools

Appian limitations

• Higher cost compared to newer platforms
• Steep learning curve for non-technical users
• Less frontend UI flexibility

Appian pricing

• Available per request

Appian ratings and reviews

• G2: 4.4/5 (471 reviews)
• Capterra: 4.2/5 (74 reviews)

FlutterFlow

FlutterFlow is a low-code builder for creating mobile and web applications using Flutter — Google's UI toolkit. Aimed at startups, agencies, and solo developers, it enables fast prototyping and full-featured app development through a visual interface that generates production-ready Flutter code.

Users can design responsive UIs with drag-and-drop widgets, define complex logic and workflows, and integrate backend services like Firebase or custom APIs. FlutterFlow also includes built-in support for animations, multi-language localization, user authentication, and even native features like push notifications.

What sets FlutterFlow apart is its ability to export clean Flutter code, allowing teams to continue development outside the platform or integrate it into CI/CD pipelines. Apps can be tested directly in-browser and deployed to the web, iOS, or Android — making it a favorite for building cross-platform MVPs fast.

FlutterFlow features:

• Visual builder for Flutter apps
• Drag-and-drop UI with full customization
• Firebase and REST API integrations
• Real-time collaboration and version control
• Exportable and editable Flutter source code
• Built-in authentication and push notifications
• Animation builder and custom actions
• Multi-language support and theming

FlutterFlow limitations:

• Best suited for Flutter-specific development
• Advanced logic and state management can get complex
• Limited support for backend customization within the tool

FlutterFlow pricing:

• Free: basic plan with core features
• Paid plans start at $30/month
• Team and Enterprise plans available by request

FlutterFlow ratings and reviews:

• G2: 4.7/5 (100+ reviews)
• Capterra: 4.8/5 (50+ reviews)

Retool

Retool low-code development tool helps engineers quickly build internal applications with full control over data and logic. Trusted by thousands of teams, Retool allows users to drag and drop ready-made UI components, write custom JavaScript, and connect to any data source – all within a developer-first environment.

With native integrations for PostgreSQL, MongoDB, REST APIs, and more, Retool significantly reduces the time required to build and maintain admin panels, dashboards, and other internal tools. Security is also a strong point, with enterprise-grade controls including audit logs, granular permissions, and SOC 2 compliance.

Retool can be deployed to the cloud or hosted on-premise, making it highly flexible for various enterprise use cases.

Retool features:

• Low-code internal tool builder
• Connect to any SQL or NoSQL database
• REST and GraphQL integrations
• Drag-and-drop UI components
• Custom logic with JavaScript
• Role-based access control
• Version control and deployment
• Works with existing APIs and auth systems

Retool limitations

• Not open-source
• Steeper pricing for larger teams
• Best suited for internal tools, not public-facing apps

Retool pricing

• Free: $0
• Paid plans start from $11 per standard (developer) user/month
• Custom pricing for enterprises by request

Retool ratings and reviews

• G2: 4.6/5 (250+ reviews)
• Capterra: 4.6/5 (33 reviews)

Appsmith

Appsmith is an open source low-code application with a lot of contributors enabling businesses to rapidly develop and deploy efficient internal apps. The features that include the drag-and-drop widgets, in-line JavaScript customization, and integration with diverse databases and APIs speed up the development and maintenance of applications 10X times quicker. In addition, the platform provides excellent security features — 256-bit encryption and secure authentication protocols.

Through Appsmith, businesses can help themselves to automate operations and create different administrative tools, including dashboards, admin panels and database GUIs. The open source nature of the platform is transparent, collaborative among communities and – also – expanding the partner ecosystem. Users deploy Appsmith firstly to the cloud or on-premise with an option of multiple installations and well-documented support materials.

Appsmith features

• Low-code application platform
• Connect to any data source
• Native integrations
• Drag and drop UI widgets
• Customize and control with code
• Git-based version control
• Built-in JS editor
• Extend existing apps

Appsmith limitations

• Limited customization options
• Potential learning curve for new users
• Reliance on external data sources for functionality

Appsmith ratings and reviews

• G2: 4.7/5 (65+ reviews)
• Capterra: 5/5 (2 reviews)

OutSystems

OutSystems is a powerful low-code platform designed for enterprises aiming to build scalable, mission-critical applications quickly. It enables teams to create both internal tools and customer-facing applications through a mix of visual development and extensible custom code.

With strong support for full-stack development, built-in CI/CD, and advanced security and performance monitoring, OutSystems is ideal for large organizations looking to modernize legacy systems or accelerate digital transformation. Developers benefit from robust debugging, version control, and integrations with enterprise systems like SAP, Oracle, and Active Directory.

The platform also includes AI-assisted development, reusable components, and deployment flexibility — from fully managed cloud to on-premise and hybrid options. Its governance and lifecycle management capabilities make it a top choice for regulated industries like finance, healthcare, and government.

OutSystems features:

• Full-stack low-code platform
• Visual development with pro-code extensibility
• Reusable UI components and business logic
• Built-in DevOps and CI/CD pipelines
• Cloud-native, on-premise, or hybrid deployment
• Enterprise-grade security and scalability
• AI-assisted development and performance tuning
• Integrations with SAP, Oracle, Azure AD, and more

OutSystems limitations:

• High licensing costs for larger teams
• Steeper learning curve for front-end customization
• Resource-intensive for self-hosted setups

OutSystems pricing:

• Free: Developer Edition (1 app, 100 users)
• Paid plans start at $1,500/month
• Custom pricing for enterprise deployments

OutSystems ratings and reviews:

• G2: 4.5/5 (500+ reviews)
• Capterra: 4.6/5 (200+ reviews)

Mendix

Mendix low-code application development platform geared toward enterprises looking to build and scale digital solutions across teams. It supports everything from internal tools to customer-facing applications, offering both no-code and pro-code environments for full collaboration.

With features like visual development, workflow modeling, and AI-assisted logic, Mendix empowers both business users and developers to co-create applications at speed. The platform also provides powerful tools for cloud deployment, DevOps automation, and governance — making it ideal for large organizations with strict compliance needs.

Mendix is available as a fully managed cloud solution or can be hosted on-premise, with support for hybrid and multi cloud environments. It’s widely used across industries like finance, logistics, and manufacturing for digital transformation at scale.

Mendix features:

• Full-featured low-code platform
• Visual and model-driven development
• Workflow automation and AI logic
• Built-in collaboration tools
• Cloud-native and on-premise deployment
• Strong governance and access controls
• Integration with SAP, Salesforce, and more
• AI-assisted app building and testing

Mendix limitations:

• Higher learning curve for complex apps
• Cost may scale quickly for enterprise plans
• Less flexible for highly custom frontend UI

Mendix pricing:

• Free: $0
• Paid plans start from €900 per month
• Custom pricing for enterprises by request

Mendix ratings and reviews

• G2: 4.4/5 (233 reviews)
• Capterra: 4.6/5 (25+ reviews)‍

Budibase

Budibase is a comprehensive open source low code platform that enables IT departments to create apps without involving external sources of data and also connecting them with existing workflows.

The users are able to merge databases, spreadsheets, and API’s together, as well as, run locally on-premise through Docker and K8s. In addition, they can create management apps, portals, form approval among other administrative functions for custom business needs.

Budibase enables you to create app schemas from data and forms without coding, use more than 40 pre-built components out of the box, and render the apps on different devices expediently. That way, it makes it possible for the automation of processes and the subsequent simplification of inputs.

Engineers can save their time by the low-code platform, Budibase, supporting various databases, REST APIS, Docker and Kubernetes. It is because the tool gives access to building forms, portals, and approval apps.

Budibase features

• Connect any database, spreadsheet or API
• Self-host on premise with Docker and K8s
• Create powerful apps and workflows from any datasource
• Management Apps
• Portals
• Approval flows
• Forms
• Admin panels

Budibase limitations

• Limited customization options
• Possible security concerns with self-hosting
• Reliance on user-friendly interfaces over advanced features

Budibase pricing

• Free: $0
• Paid plans start from $5 per app user/month
• Custom pricing for enterprises by request

Budibase ratings and reviews

• G2: 4.5/5 (68+ reviews)‍

Best low-code tools comparison table

Last thoughts

In 2025, low-code tools are no longer niche helpers – they’re core components of modern development workflows. Whether you're an enterprise managing complex infrastructure or a solo founder prototyping your next big idea, there’s a low-code platform tailored to your needs. From open-source to AI-powered, the ecosystem offers speed, scalability, and control in one package. The best choice depends on your team's goals, skills, and required level of customization.

FAQ

• What is the difference between low-code and no-code tools?

Low-code tools require some coding (often JavaScript, Python, or SQL), while no-code platforms are designed for non-technical users with visual-only interfaces.

• Can low-code tools be used to build public-facing applications?

Yes, some tools like OutSystems, Mendix, and FlutterFlow support building full-featured, public-facing apps.

• Which tool is best for enterprise use?

UI Bakery, OutSystems, Appian, Mendix, and Superblocks offer enterprise features like RBAC, SOC 2, and on-prem deployment.

• Is open-source better than proprietary low-code platforms?

Open-source tools like Appsmith, Budibase, and ToolJet provide transparency and customization, while proprietary platforms often offer richer enterprise features and support.

• Do low-code platforms support AI-powered development?

Yes, platforms like Superblocks and Mendix now include AI-assisted logic and automation to help speed up development.

• Can I self-host low-code platforms?

Yes, several platforms like UI Bakery, Budibase, Appsmith, and ToolJet offer on-premise or self-hosted deployment options.