Freedom251 › No-code app builders
REI3
by REI3
What REI3 is
REI3 is an open-source business application platform for deploying existing applications or building new ones. Its graphical Builder lets teams define data structures, interfaces, and record access, while the built-in database, authentication, and API integrations support complete application setups. Applications can include forms, workflows, schedulers, notifications, access policies, file and email processing, and CSV import or export. REI3 can run on-premise or in the cloud and is accessed through a modern browser, including mobile browsers and progressive web app installation on iOS and Android. Connectors cover REST APIs, LDAP and Active Directory, OpenID Connect, SMTP, IMAP, and ICS calendars. Security features include end-to-end encryption with user key management, multi-factor authentication, and role- and record-level controls. A free plan costs nothing, while Professional pricing is listed from €3.50 per user and month for 101+ users. A public demo is available without registration.
Who it suits
REI3 is suited to teams creating internal software, including replacing spreadsheet- or Access-based multi-user processes. It also fits organizations wanting browser-based, self-hosted or cloud applications.
What it does well
- Graphical Builder defines data, interfaces, and access
- Supports on-premise and cloud hosting
- Includes workflows, schedulers, and notifications
- Offers encryption and multi-factor authentication
- Free plan has no user limit
What to know first
- Built on web technologies rather than native applications
- Free support is best-effort contact-form support
- Professional licensing uses concurrent users
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free | No user limit · unlimited storage, API calls, email handling, backend processing, frontend scripts and app developers | Free |
| REI3 Professional (1–10 users) | Per user & month · 1–10 users · 3 additional limited users per licensed user | €5.50 a month |
| REI3 Professional (11–25 users) | 11–25 users · 3 additional limited users per licensed user | On request |
| REI3 Professional (26–50 users) | Per user & month · 26–50 users · 3 additional limited users per licensed user | €4.50 a month |
| REI3 Professional (51–100 users) | 51–100 users · 3 additional limited users per licensed user | On request |
| REI3 Professional (101+ users) | Per user & month · 101+ users · 3 additional limited users per licensed user | €3.50 a month |
| REI3 Professional | per user & month; 101+ users · Concurrent-user licensing · 3 additional limited users per licensed user | €3.50 a month |
As rei3.de lists them, read 12 Oct 2026. The maker's own page has the final word.
Verdict
REI3 combines application building, deployment choices, integrations, and access controls in one platform. Its free offering provides a starting point, while Professional tiers add a concurrent-user licensing model and defined support response time.
Facts from REI3's own pages
- API integrations
- Yes · rei3.de, 22 Sept 2026
- App authenticity
- The official application repository's apps are checked and signed by REI3 developers; third-party app signatures can be verified before installation. · rei3.de, 12 Oct 2026
- App types
- web · rei3.de, 22 Sept 2026
- Availability
- A public demo system is available for live testing without registration. · rei3.de, 12 Oct 2026
- Built-in database
- Yes · rei3.de, 22 Sept 2026
- Deployment
- REI3 can be hosted on-premise or in the cloud, and its applications are accessed from devices with a modern browser. · rei3.de, 12 Oct 2026
- Free plan
- Yes · rei3.de, 22 Sept 2026
- Headquarters
- Munich, Germany · rei3.de, 28 Sept 2026
- Integrations
- Connectors include REST APIs, LDAP and Active Directory, OpenID Connect, SMTP, IMAP, and calendar data via ICS. · rei3.de, 12 Oct 2026
- Mobile access
- REI3 supports mobile browsers and can be installed to the home screen on iOS and Android as a progressive web app. · rei3.de, 12 Oct 2026
- Notable limitation
- The maker notes that REI3 is built on web technologies and that native applications can have benefits outside a browser. · rei3.de, 12 Oct 2026
- Professional license limits
- Professional licensing is based on concurrent users, and each licensed user includes three limited users who cannot be administrators and can have only one application role. · rei3.de, 12 Oct 2026
- Purpose
- REI3 is an open-source business application platform for deploying existing apps or building new applications to meet software requirements. · rei3.de, 12 Oct 2026
- Security
- REI3 supports built-in end-to-end encryption with user key management, multi-factor authentication, and role and record-level access controls. · rei3.de, 12 Oct 2026
- Support
- The free offering lists contact-form support with best-effort response, while Professional lists email support with a one-work-day response time. · rei3.de, 12 Oct 2026
- User authentication
- Yes · rei3.de, 22 Sept 2026
- Visual builder
- Applications are built with a graphical Builder for defining data structures, user interfaces, and record access. · rei3.de, 12 Oct 2026
- Who it is for
- The maker describes REI3 as particularly strong for internal software needs, including replacing spreadsheet or Access-based multi-user processes. · rei3.de, 12 Oct 2026
- Workflow and data features
- The platform supports forms, workflows, schedulers, notifications, access policies, file and email processing, and CSV import/export. · rei3.de, 12 Oct 2026
Where REI3 stands on Freedom251
- No-code app builders#37 of 177