Free, open-source alternatives to OutSystems
Low-code platform for business apps. 4 apps you can run yourself instead of OutSystems, sorted by how well they replace it. Each one is open source, so your data stays with you.
BudibaseBest match
Build and automate internal tools, admin panels, dashboards, CRUD apps, and more, in minutes (alternative to Outsystems, Retool, Mendix, Appian).
Appsmith
Build admin panels, CRUD apps and workflows. Build everything you need, 10x faster.
ToolJet
Low-code framework to build & deploy internal tools with minimal engineering effort (alternative to Retool and Mendix).
Saltcorn
No-code database application builder for web and mobile applications. One platform for user interface, data backend, durable workflows, email, PDF generation, and AI applications.
Side by side
Why replace OutSystems?
OutSystems works, but your data lives in someone else's account, the price can change at any time, and features can disappear. An open-source app you run yourself is yours: you choose where it runs, who can see the data, and when to update.
Questions
What is the best free alternative to OutSystems?
Budibase is the closest open-source replacement for OutSystems in our list. Appsmith and ToolJet are worth a look too, depending on what you need.
Can I self-host an alternative to OutSystems?
Yes. All 4 apps on this page are open source and can run on your own server, usually with Docker, or on a managed host that installs them for you.