Do I need both products?

No. Each one works independently. Many teams start with just the open-source Core and add Sync when their app needs offline-first data — and Sync also works with apps that weren't built with Core. You only adopt, and pay for, what you use.

Which databases does Sync work with?

Sync runs on top of the database you already use — PostgreSQL, MySQL/MariaDB, SQL Server, Oracle and MongoDB — with SQLite and a durable mutation queue on the device.

Is the Core really open source?

Yes. CrossFly Core is open source and free to use, built on the LibGDX/Java stack. You can read the code, follow the roadmap and contribute on GitHub.

How do the products connect?

Apps built with Core sync their data through Sync: the device stays the primary source, writes queue up while offline, and they reconcile with your server when the connection returns — one vendor and one model end to end, instead of two disconnected tools.

THE CROSSFLY PLATFORM

One platform to build your apps and keep them in sync

Q: What is CrossFly, the platform?

CrossFly is one platform for building and running cross-platform apps: Core builds native apps for Desktop (Windows, macOS and Linux), Android, iOS and the web (Chrome, Firefox, Safari and other browsers) from one Java codebase, and Sync keeps their data consistent offline-first, on top of your database — both from a single vendor, each useful on its own.

Write your app once in Java and ship it as a truly native app on Desktop (Windows, macOS and Linux), Android, iOS and the web (Chrome, Firefox, Safari and other browsers) — then keep its data in sync offline-first, on top of the database you already use. Build → Sync.

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One platform · Core + Sync

BuildSync

CrossFly

Platform

CrossFly Core

Available

CrossFly Sync

Available

THE PRODUCTS

Two products, built to work together

Each one stands on its own — together they take your app from the first line of code to reliable data in the field. Adopt what you need today.

CrossFly Core

Core

Native Android · iOS · Windows · macOS · Linux · Web apps in pure Java (LibGDX).

Learn more

CrossFly Sync

Offline-first

Offline-first sync for any stack and database.

Learn more

HOW IT FITS TOGETHER

From the first line of code to data in the field

Write the app once, ship it everywhere and keep its data consistent — even offline. No stitching a UI framework and a sync engine together from different vendors.

Build

Ship apps for Android, iOS, Desktop (Windows, macOS and Linux) and the web (Chrome, Firefox, Safari and other browsers) from one Java codebase with CrossFly Core.

CrossFly Core

Sync

Keep data consistent everywhere — offline-first — with CrossFly Sync, for any stack and database.

CrossFly Sync

BUILT FOR YOUR WHOLE TEAM

One platform, every role

Developers, field operations and decision-makers — everyone works from the same foundation.

Developers

Build native apps in pure Java and sync data offline-first, without gluing SDKs together.

Core · Sync

Field & operations teams

Apps that keep working without signal and sync on their own when the connection returns — no lost orders, no retyping.

Core · Sync

Business & decision-makers

One vendor, one contract, one roadmap — from the app to its data, on an open-source foundation.

Core · Sync

WHY THE PLATFORM

Why teams choose the CrossFly ecosystem

Not tools bolted together — one platform, designed to fit.

One integrated platform

The products are designed to work together, not stitched from separate vendors with mismatched models.

Java-first, open-source core

Build in pure Java on an open-source foundation — inspect it, extend it, and never get locked out.

Offline-first & secure by design

Apps keep working without a connection, and data moves over encrypted, modern transports.

Every screen, one codebase

Desktop (Windows, macOS and Linux), Android, iOS and the web (Chrome, Firefox, Safari and other browsers) from the same Java project — one team, one build, one behaviour everywhere.

One vendor, one contract

A single partner across the whole lifecycle — simpler procurement, aligned support, one roadmap.

Adopt at your pace

Start with the open-source Core for free, and add Sync when your app needs offline-first data.

BUILT TO BE TRUSTED

Open where it counts, built on proven tech

No smoke and mirrors — the foundation is open source and the stack is battle-tested.

The Core is open source

CrossFly Core is developed in the open. Read the code, follow the roadmap, and contribute.

View on GitHub

Built on proven technology

JavaLibGDXRustgRPCPostgreSQL

We're honest about where we are: everything on this page is available today.

PRICING

Start free with the Core

CrossFly Core is free and open source. Commercial plans cover CrossFly Sync. Pay only for what you use.

See pricing

FAQ

Questions about the platform

Ready to build on the CrossFly ecosystem?

Start free with the open-source Core, or talk to us about Sync for your team.

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