Syncthing-Fork

Open-source peer-to-peer file sync for Android, honestly reviewed. What you actually get when the original app is discontinued and a fork steps in.

TL;DR

• What it is: An Android wrapper for Syncthing — the MPL-2.0-licensed, peer-to-peer file sync engine — maintained as a community fork after the official Android app was discontinued in late 2024 [4].
• Who it’s for: Self-hosters who want to sync files between Android phones, Linux boxes, NAS devices, and PCs without paying for cloud storage or routing data through third-party servers [1][2].
• Cost savings: Dropbox, OneDrive, and iCloud charge $10–20/mo for meaningful storage. Syncthing-Fork costs $0. Pair it with a $5/mo VPS as a permanent relay node and you have always-on sync for less than a cup of coffee [2][5].
• Key strength: It’s the only actively maintained Syncthing client for Android. When the official app died, this fork survived — and it ships battery-friendly enhancements the original lacked [4].
• Key weakness: No Google Play Store distribution. Sideload from F-Droid or GitHub, which is a real barrier for non-technical users. Also, Syncthing’s core model (both devices must be online simultaneously, or you need a relay node) is less convenient than cloud storage for many people [2][4].

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What is Syncthing-Fork

Syncthing-Fork is an Android application that wraps the core Syncthing binary — the open-source, peer-to-peer file synchronization engine — and makes it work as a native Android app. It is a fork of the now-archived official syncthing/syncthing-android repository, currently maintained at researchxxl/syncthing-android under the MPL-2.0 license [4][README].

To understand why it exists, you need to know what killed the original. The official Syncthing for Android app was maintained by imsodin (Simon Frei), who had been dealing with Google Play Store rejections since February 2024 — Google was denying storage permissions the app needed to function. Combined with frustrated users and maintainer burnout, the project was officially retired with a final update planned for December 2024 [4].

Syncthing-Fork stepped into that gap. It had been running in parallel as an enhanced alternative before the official app died, and now it’s the de facto standard for Syncthing on Android. The gHacks piece on the discontinuation explicitly names it as the app to switch to [4]. The French stackgui.de review, written after testing in a live session, calls it “today’s recommended” option and notes “it works very well” [5].

As of the latest release (v2.0.15.0, March 5, 2026), the project has 1,361 GitHub stars, 47 forks, and 3,722 commits across its history. It’s available via F-Droid and Obtainium — not Google Play [README].

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Why people choose it (and why they stay)

The case for Syncthing-Fork starts with the case for Syncthing itself, which is a different value proposition than most sync tools.

The no-cloud-server argument. Every other sync option — Dropbox, Google Drive, iCloud, OneDrive, even self-hosted Nextcloud — routes your files through a server. That server is either a third-party’s machine (meaning your data is their asset) or your own machine running heavyweight server software. Syncthing’s P2P architecture means your files go device-to-device directly, with no intermediary in the default setup [2][5]. Sumukh Rao’s XDA piece frames this plainly: uploading to cloud storage means “my data is stored on third-party servers, which always poses a risk — especially when uploading sensitive documents and files” [2].

The “it’s not backup” clarification. Multiple reviewers are careful to note this because people get confused: Syncthing synchronizes files, it doesn’t back them up. If you delete a file on one device, that deletion propagates everywhere (unless you configure send-only or receive-only modes). Ayush Pande’s XDA piece makes this distinction explicit — he ended up using Syncthing alongside his NAS backup setup, not instead of it [1]. This is an important mental model: Syncthing is for keeping working copies of files identical across devices, not for disaster recovery.

The Android gap. Before the official app died, Android users had a working client. After December 2024, Syncthing-Fork became the only maintained path. GHacks notes the fork “retains the original app’s functionality” while adding “extra features and battery-friendly enhancements” [4]. For users already in the Syncthing ecosystem who sync game saves (Ayush Pande mentions losing Helldivers 2 progress as his catalyst for adopting Syncthing [1]), documents, or photos to a NAS, losing the Android client would have broken the whole setup. Syncthing-Fork prevented that.

Against Nextcloud. The XDA piece by Rao explicitly mentions Nextcloud as the other self-hosted option he evaluated before settling on Syncthing: “even Nextcloud can get rather clunky for some users, especially since it offers a bucket load of features apart from just file sharing. So if you’re only looking for a solution to access your files remotely without a productivity suite or other additions, you will have to look elsewhere” [2]. Syncthing wins on simplicity and resource footprint when all you need is sync. It loses when you need file management, sharing links, collaboration, or a web interface for browsing files.

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Features

What Syncthing-Fork provides on Android, based on the README, F-Droid listing, and review coverage:

Core sync:

• Full Syncthing binary wrapped for Android — all desktop Syncthing functionality is accessible [README][4]
• Bidirectional, send-only, and receive-only folder modes [1]
• File versioning (configurable number of versions to keep) [1]
• Automatic conflict resolution when the same file is edited on two devices

Android-specific:

• Battery-friendly sync scheduling — the fork’s main enhancement over the original [4]
• Background sync with configurable conditions (WiFi only, charging only, etc.) [README]
• Notification support for sync status
• Available via F-Droid and Obtainium; not on Google Play [4][README]

Network and discovery:

• Local network auto-discovery — devices on the same LAN find each other without configuration [5]
• Global relay network for syncing when devices are on different networks
• Untrusted device support: you can sync to a VPS with client-side encryption enabled, so the relay node never sees your plaintext files [5]
• NAT traversal built-in via Syncthing’s relay infrastructure [2][5]

Translations:

• Available via Weblate — multiple languages contributed by community translators [README]

What it doesn’t do:

• No Google Play Store distribution — sideload only [4]
• No iOS client (Möbius Sync exists as a third-party paid option, but it’s not part of this project) [4]
• No web browser access to your files — this is a sync tool, not a file server [2]
• No sharing links or collaborative editing

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Pricing: SaaS vs self-hosted math

Syncthing-Fork: $0. MPL-2.0 license, open source, no subscription, no account [README].

What you might spend on infrastructure:

• Pure P2P (two devices, same LAN): $0/month. Works out of the box, no server needed [2][5].
• Always-on relay node (VPS): $4–6/month on Hetzner or Contabo. This solves the “both devices need to be online” limitation. The VPS acts as a permanent node — changes sync to it when you’re connected, and other devices pull from it when they reconnect [5].
• NAS-based relay: $0/month ongoing if you already own a NAS. TrueNAS Scale, Unraid, Synology DSM, and TerraMaster TOS all include Syncthing in their app stores [1].

For comparison:

• Dropbox: $9.99/mo (2TB, 1 user)
• Google One: $2.99/mo (100GB) — $9.99/mo (2TB)
• iCloud+: $2.99/mo (200GB) — $9.99/mo (2TB)
• OneDrive: $1.99/mo (100GB) — $6.99/mo (1TB, Microsoft 365 Personal)

The math is straightforward: if you have a NAS already, your ongoing cost for Syncthing is zero. If you add a $5 VPS as an always-on relay, your annual bill is $60 — less than one month of Dropbox with comparable storage.

The caveat: cloud storage providers give you a web interface, sharing links, automatic photo backup with AI organization, and cross-platform apps including iOS. Syncthing gives you none of that — it gives you raw sync. If those cloud features are worth $120/year to you, that’s a legitimate trade.

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Deployment reality check

On Android itself: Install from F-Droid or Obtainium. F-Droid is a free app store for open-source Android apps — if you’ve never used it, you’ll need to enable sideloading in Android settings. The F-Droid install process takes about 5 minutes. Syncthing-Fork is not on Google Play, which is a hard stop for users who don’t know what sideloading means [4].

Pairing devices: The pairing workflow is ID-based. Each Syncthing instance generates a device ID (a long alphanumeric string). You add the other device’s ID, accept the pairing request on that device, then share specific folders. The stackgui review describes local network auto-discovery as seamless — devices find each other automatically and the pairing request just appears [5]. Remote pairing (different networks) requires more manual coordination.

The relay node problem: Pure P2P sync requires both devices to be online simultaneously. If you modify a file on your laptop and your phone is off, that change doesn’t reach your phone until the next time both are running. The standard solution is a permanent relay node — a VPS or NAS that’s always on [5]. Setting up a VPS as a Syncthing node requires basic Linux comfort: install Syncthing on the VPS, add it as a shared device, configure the folder. The stackgui review covers this as a core use case and calls it a “hybrid configuration between pure P2P and server mode” [5].

Untrusted device encryption: If you use a third-party VPS, you can configure Syncthing to encrypt files before they leave your device, so the VPS only ever stores ciphertext. The stackgui piece explains the flow: you set a password client-side, the VPS receives pre-encrypted files, trusted devices decrypt on-the-fly [5]. This is a meaningful privacy feature that Dropbox and Google Drive don’t offer.

Platform coverage for the broader Syncthing setup:

• Linux: package manager or binary download
• macOS: binary or Homebrew
• Windows: binary + SyncTrayzor GUI (though gHacks notes SyncTrayzor hasn’t been updated in a while; Syncthing Tray is the current alternative) [4]
• TrueNAS Scale, Unraid, Synology: native app store [1]
• Android: Syncthing-Fork via F-Droid [4]
• iOS: Möbius Sync (paid, third-party, not this project) [4]

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Pros and Cons

Pros

• The only maintained Android Syncthing client. After the official app retired in December 2024, this fork is the path forward for Android users [4].
• Battery-friendly enhancements. Sync scheduling and charging/WiFi conditions are configurable — the fork specifically addressed battery drain concerns the original had [4].
• True P2P architecture. No company has access to your files in transit. No relay server sees plaintext (if you use untrusted device encryption) [2][5].
• Practically zero ongoing cost. No subscription, no per-GB fees, no account required. Pair with an existing NAS and the running cost is zero [2][5].
• Works with the full Syncthing ecosystem. NAS devices, Linux servers, Windows, macOS — they all have Syncthing clients. The Android piece was the missing link; this fork fills it [1][4].
• Untrusted device encryption. You can use a cheap VPS as a relay without trusting the VPS provider with your data [5].
• Local network sync is completely serverless. On the same LAN, devices sync directly with zero infrastructure [5].
• MPL-2.0 license. Permissive, no cloud vendor lock-in, no “fair code” restrictions.

Cons

• No Google Play Store. Sideloading is required. For non-technical users, this is a real barrier — not a minor inconvenience [4].
• Both devices must be online simultaneously (without a relay). Pure P2P sync has an availability limitation that cloud storage doesn’t. The relay workaround works, but requires extra setup [2][5].
• Not a backup solution. Deletions propagate. Mistakes on one device replicate everywhere. File versioning helps but it’s not a substitute for actual backup [1].
• No iOS equivalent in this project. iPhone users need a third-party paid app (Möbius Sync) that isn’t part of this ecosystem [4].
• No web UI for browsing files. You can’t access your synced files from a browser without a separate file server. This is a sync daemon, not a cloud drive [2].
• Relatively low GitHub activity on the fork. 1,361 stars and 47 forks suggests a smaller contributor base than the original project had. Bus factor risk for a one-maintainer fork.
• Setup complexity scales with your needs. LAN sync is trivial. Cross-network sync with always-on relay and untrusted encryption is a multi-step project.

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Who should use this / who shouldn’t

Use Syncthing-Fork if:

• You’re already using Syncthing across your devices and need an Android client after the official app retired.
• You have a NAS or home server and want your Android phone to sync with it automatically without routing files through anyone’s cloud.
• You sync sensitive documents (legal, financial, health) and want zero third-party exposure.
• You’re comfortable with F-Droid and basic Linux server setup.
• You want to sync game saves, code projects, or specific working folders — not your entire photo library.

Skip it (use Google Photos or iCloud instead) if:

• You want a “set it and forget it” automatic photo backup that works even when you don’t think about it.
• You need sharing links to send files to people who aren’t in your Syncthing network.
• You’re not comfortable enabling sideloading on Android.
• You need iOS support — there’s no first-party iOS client.

Skip it (use Nextcloud instead) if:

• You want a web interface to browse, share, and manage files from any browser.
• You need calendars, contacts, document collaboration, or other productivity features alongside file sync.
• You want a full cloud storage replacement, not just a sync layer.

Skip it (use Tailscale + direct SMB/NFS) if:

• Your use case is primarily accessing files remotely from a fixed home server and you don’t need bidirectional sync across multiple peer devices.

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Alternatives worth considering

• Syncthing (desktop/server) — The upstream project that Syncthing-Fork wraps. Actively maintained for Linux, macOS, Windows. 80,000+ GitHub stars [5].
• Nextcloud — The full self-hosted cloud platform. More features, more complexity, more resource consumption. Better if you want a cloud drive replacement rather than pure sync [2][3].
• Nextcloud Talk / Files only — You can deploy Nextcloud with only the Files app enabled to reduce complexity, though it’s still heavier than Syncthing [3].
• FreeFileSync — Folder comparison and sync for desktop only (Linux, macOS, Windows). No mobile. Good for scheduled one-way or two-way desktop syncs [3].
• Seafile — Self-hosted file sync with a client-server model. Lighter than Nextcloud, heavier than Syncthing. Has official Android and iOS apps.
• Möbius Sync — Third-party Syncthing client for iOS. Not free, not open source in the same way, but the only option if you need iPhone in your Syncthing setup [4].
• Filen — End-to-end encrypted cloud storage with native Android/iOS apps. Freemium, open source (AGPL). A different trade-off: gives up P2P for convenience, gains zero-knowledge encryption at the provider level [3].
• Proton Drive — Privacy-focused cloud storage from Proton. Paid for meaningful storage. Easier for non-technical users, less control [3].

For strictly file sync (not full cloud storage), the realistic shortlist is Syncthing-Fork vs Nextcloud Files. Pick Syncthing-Fork if you want minimal infrastructure, zero cloud vendor exposure, and P2P simplicity. Pick Nextcloud if you want web access, sharing links, and a broader feature set.

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Bottom line

Syncthing-Fork exists because the official Android client doesn’t. That’s the honest starting point. It’s not a flashy new product — it’s a fork that stepped up to maintain continuity when the original maintainer burned out on Google’s bureaucracy. For people already in the Syncthing ecosystem, the choice is simple: this is the Android client now, it works, and it ships improvements the original didn’t have.

For founders evaluating whether Syncthing makes sense at all: if your use case is “stop paying Dropbox to hold my sensitive documents” and you have any technical comfort with Linux, the math is obvious. A $5 VPS relay node and F-Droid install replaces a recurring SaaS bill permanently. If you want photos organized with AI, sharing links, and apps that work the same on Android and iPhone without configuration — stick with cloud storage. Syncthing is for people who want to own the sync layer, not rent it.

If setting up the relay node is the blocker, that’s exactly what upready.dev deploys for clients. One-time setup, you keep the infrastructure.

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Sources

1. Ayush Pande, XDA Developers — “I self-host Syncthing to sync files between my PC, Mac, NAS, and other devices” (Jul 25, 2025). https://www.xda-developers.com/i-self-host-syncthing-to-sync-files-between-my-pc-mac-nas-and-other-devices/
2. Sumukh Rao, XDA Developers — “Syncthing ruined cloud storage for me in the best possible way” (Aug 24, 2025). https://www.xda-developers.com/syncthing-ruined-cloud-storage-best-way/
3. AlternativeTo — “Open Source Apps tagged with ‘File Sync’”. https://alternativeto.net/category/backup-and-sync/file-synchronization/?license=opensource
4. Martin Brinkmann, gHacks Tech News — “Syncthing for Android is being discontinued, but there’s an alternative app” (Oct 21, 2024). https://www.ghacks.net/2024/10/21/syncthing-for-android-is-being-discontinued-but-theres-an-alternative-app-you-can-switch-to/
5. stackgui.de — “Syncthing : synchroniser ses fichiers en pair-à-pair, sans serveur centralisé”. https://www.stackgui.de/syncthing-synchronisation-fichiers-p2p-sans-serveur/

Primary sources:

• GitHub repository (Syncthing-Fork): https://github.com/researchxxl/syncthing-android (1,361 stars, MPL-2.0, latest release v2.0.15.0)
• F-Droid listing: https://f-droid.org/packages/com.github.catfriend1.syncthingfork
• Syncthing upstream project: https://github.com/syncthing/syncthing