REI3 review
A low-cost, self-hosted builder for structured browser-based business apps.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
REI3 is an open-source low-code platform for creating and running multi-user business applications. Its graphical builder covers data stores, relationships, forms, workflows, access controls, APIs, notifications and integrations. Organizations can host applications on-premises, in a private cloud or on self-managed infrastructure, making REI3 suited to teams replacing spreadsheets, shared mailboxes or custom internal tools. Browser access and progressive-web-app support are part of its published positioning.
Pricing is structured around a free plan and optional Professional licensing. The Free plan includes local installation, unlimited storage, unlimited API calls, unlimited email handling and unlimited backend processing. Professional features and services include email support with a one-workday response time. Published per-user monthly prices are €5.5 for 1–10 users, €4.5 for 26–50 users and €3.5 for 101+ users; the other listed Professional bands carry the same feature and support description. This makes the product particularly relevant when controlling hosting and licensing costs matters.
REI3’s strongest fit is for structured internal applications that need built-in data management, role-based and record-level access policies, REST APIs, authentication options and operational features such as integrated backups and database upgrades. Its ecosystem includes REST APIs, LDAP, Active Directory, OpenID Connect, SMTP, IMAP, ICS/iCalendar, CSV and Microsoft 365 OAuth2. End-to-end encryption and multi-factor authentication add useful controls for business deployments, while application export, signing and reusable modules support movement between REI3 instances. Choose REI3 for low-cost, self-hosted web applications with business workflows and controlled access. Teams seeking AI features or a product centered on native mobile-app publishing should look elsewhere.
REI3 pros and cons
- Where it wins
- Open source with local installation and a free plan
- Built-in data stores, permissions, APIs and authentication
- Backups, encryption and multiple business-focused views
- Where it doesn't
- Published positioning centers on browser-based applications
- No AI features are included
- Professional pricing uses several user-count bands
REI3 fact sheet, pricing and score →
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