The question is not which file sync service has the slickest mobile app. The question is whose servers your files live on and what that costs: money, privacy, and attack surface.
Syncthing gives you one answer. Dropbox and Google Drive give you a different one.
What Syncthing Actually Does
Syncthing is a peer-to-peer file synchronization tool. There is no Syncthing server in the middle. When your laptop syncs with your desktop, those files travel directly between those two machines — encrypted in transit using TLS with a key exchange that does not route through any central infrastructure. The Syncthing Foundation maintains relay servers that help devices find each other, but those relay servers never receive file contents.
The Block Exchange Protocol transfers only changed blocks within files rather than uploading and re-downloading whole files. For large files where you edit a few paragraphs, this is significantly more efficient than cloud sync tools that upload the entire file on each change.
Around 65,000 GitHub stars. Written in Go. Runs on Windows, Mac, Linux, BSD, and Android. No account registration. No subscription. No licensing fee. The software is free to download, install, and run.
The Pricing Comparison
| Syncthing | Dropbox | Google Drive | |
|---|---|---|---|
| Cost | Free forever | Plus: $9.99/mo (annual) | 15GB free; 100GB for $2.99/mo |
| Storage limit | Your own hardware | 2TB on Plus | Up to 30TB via Google One |
| Cloud dependency | None | Yes | Yes |
| Link sharing | No | Yes | Yes |
| iOS client | Third-party only | Yes | Yes |
| E2E encryption | Yes, built in | Optional add-on | No native E2E |
At Dropbox's current pricing, the Plus plan runs $9.99/month billed annually ($119.88/year) for 2TB of cloud storage. Essentials at $16.58/month adds features for freelancers. Business plans for teams start at $15/user/month.
Google One starts at $2.99/month for 100GB and scales to $9.99/month for 2TB. That 2TB is shared across Gmail, Drive, and Google Photos. If you're on Google Workspace, your Drive storage is included in the plan cost and this calculation shifts.
Syncthing costs whatever your hardware costs. A 4TB external drive runs $80-100 once. The ongoing expense is electricity.
The Security Architecture That Changes the Conversation
For anyone evaluating tools with privacy or compliance in mind, the Syncthing model deserves serious attention.
Dropbox and Google Drive are cloud storage services. Your files sit on their servers, encrypted at rest with keys they manage. Google states in its terms that it scans files for policy violations. Both companies receive government data requests. Dropbox has acknowledged receiving National Security Letters. Neither can technically protect your files from a legally compelled disclosure, because they hold the decryption keys.
Syncthing's threat model is different. The only places your files exist are the devices you explicitly configure. There is no Syncthing Inc. that could be compelled to produce your data, because Syncthing Inc. has no access to it. The Syncthing security documentation describes the full cryptographic model — each device generates a unique certificate, and peers authenticate to each other using those certificates directly.
For teams handling sensitive intellectual property, regulated financial data, or personal health records, this architectural difference is material. Self-hosted file sync with no third-party cloud dependency means you own the entire chain of custody.
What Syncthing Gets Wrong
The trade-offs are real.
Both devices must be online simultaneously to sync. If your laptop is at home and your work desktop is at the office, files sync only when both machines are running and connected. There is no cloud buffer that stores your changes until the other device reconnects. Syncthing is a sync service, not a backup service.
No official iOS client exists. Mobius Sync is a third-party iOS app that implements the Syncthing protocol. It works, but it is not free and is not open source. This is the most common complaint in Syncthing threads, and it is a legitimate gap. Android support is solid and official.
No link sharing. You cannot send someone a URL to download a Syncthing file the way you do with Dropbox or Google Drive. If you need to exchange files with external collaborators, vendors, or clients, Syncthing does not solve that problem.
Conflict resolution produces copies. When two devices modify the same file and both changes cannot be automatically merged, Syncthing creates a conflict copy with a timestamp in the filename. You manually review and delete the version you do not need. This is the correct behavior from a data integrity standpoint, but it surprises users expecting silent cloud-style resolution.
Initial setup takes 20 minutes and some comfort with networking. You install Syncthing on each device, open the web UI at localhost:8384, exchange device IDs, add folders, and configure sync direction. There is no "sign in and it works" path.
When Dropbox Is the Right Answer
Dropbox is built for collaboration across organizational boundaries. You share a link and anyone with a browser can access the file without installing anything. You grant edit access to a folder and an external contractor can work in it from their existing device.
Dropbox's version history, mobile apps, and selective sync are genuinely well-implemented. For freelancers and agencies exchanging files with clients, the collaboration infrastructure justifies the price in ways that pure personal sync does not.
The consistent complaint across productivity communities: Dropbox's pricing has increased while the product has stagnated for solo users who are not using the collaboration features. If you are paying for Plus and mostly syncing files between your own devices, you are paying for margins on features you do not use.
When Google Drive Is the Right Answer
Google Drive is the right answer when you are already embedded in the Google ecosystem. If your team uses Gmail, Google Docs, and Sheets, Drive is effectively your existing file system and using anything else adds friction.
Google One's 2TB plan at $9.99/month covers Google Drive, Gmail, and Photos under a single storage quota. For users managing photo archives alongside work documents, that bundled value is hard to replicate.
The limitation: Google's business model involves your data. Their terms permit scanning for policy compliance and enforcement. For anyone with a legitimate reason to keep files away from hyperscaler infrastructure, this is a disqualifying characteristic.
Who Should Use Each
Syncthing is right for:
- ▸Anyone with two or more personal devices that are online regularly
- ▸Files that stay within your own household or organization and do not need external sharing
- ▸Teams with compliance requirements that preclude third-party cloud hosting
- ▸Linux and Android users, where Syncthing has the most polished native experience
- ▸Anyone willing to do a one-time 20-minute setup in exchange for $0/month forever
Dropbox is right for:
- ▸Freelancers and agencies who exchange files with external clients regularly
- ▸Users who need to access files from devices they do not control
- ▸Anyone on iOS who needs mobile sync to work without configuration
- ▸Teams who value Dropbox's version history and recovery features
Google Drive is right for:
- ▸Google Workspace users for whom Drive is already the default
- ▸Anyone using Google Docs and Sheets as their primary document tools
- ▸Users who want email, file, and photo storage on a single shared quota
For teams considering a broader shift toward self-hosted infrastructure, Syncthing fits naturally alongside the tools covered in our guide to self-hosted SaaS alternatives. The same privacy argument that applies to file sync applies to photos, and we compared the cloud versus self-hosted trade-off directly in our Immich vs Google Photos review.
The Bottom Line
Syncthing is the right answer for anyone whose primary need is keeping their own devices synchronized with no third-party in the chain. The lack of iOS client and link sharing are real gaps — if those match your actual requirements, they are disqualifying.
Dropbox wins if external collaboration and mobile reliability are worth $120/year. Google Drive wins if you are already in Workspace and want one less vendor to manage.
The harder truth about cloud storage: most individuals and small teams are paying for infrastructure they do not need. If you run Linux or have a home server, install Syncthing, configure it in 20 minutes, and see whether you actually miss what you are paying $10-15/month for. Most people who try it do not go back.