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REI3

Freemium#78 of 173 in No-Code App Builders

REI3: A low-cost, self-hosted builder for structured browser-based business apps. Ranked #78 of 173 in No-Code App Builders by our editors (3.0/10); pricing: Free plan; best for low-cost self-hosted web applications.

3.0/10Editor score

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REI33.0 Visit REI3

At a glance

Editor score
3.0 / 10
Pricing
Free plan
Best for
Low-cost self-hosted web applications
Free plan
Yes
Paid from
€4.50/user/mo
App types
Web
Facts checked
22 Sep 2026

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

Our verdict on REI3

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.

Your product? Our editors can test REI3 in depth and publish a review, labelled as paid · from $149/mo →

REI3 pricing

Plans Free planFreemium A usable free plan; paid tiers unlock the limits above. Prices checked 22 Sep 2026.

See plans on rei3.de

All 6 REI3 plans and prices →

REI3 fact sheet

Free plan	Yes
Paid from	€4.50/user/mo
App types	Web
Mobile publishing	Not verified
Built-in database	Yes
User authentication	Yes
API integrations	Yes
App limit	Not verified
Data limit	Not verified
Deployment	Cloud, Self-hosted, Browser extension
Platforms	Web, Windows, Linux
Compliance & security	2FA
Support	Email, Community, Docs
Built for	Small business, Mid-market, Enterprise (editorial estimate)
Integrations	9 integrations: REST APIs, LDAP, Active Directory, OpenID Connect, SMTP, IMAP …
Pricing	Free plan (source)
Website	rei3.de
Facts checked	22 Sep 2026

REI3 integrations

REI3 lists 9 integrations on its own site.

REST APIs
LDAP
Active Directory
OpenID Connect
SMTP
IMAP
ICS/iCalendar
CSV
Microsoft 365 OAuth2

Alternatives to REI3

See all REI3 alternatives →

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The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used REI3 for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.

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Featured on iTechGuides

REI3 is listed in our No-Code App Builders directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update