9 Best File Sync Software of 2026

Syncthing is the strongest answer for keeping folders identical across your own computers. Its site describes it as a continuous file synchronization program that syncs between two or more computers in real time, and its FAQ is explicit that it does not upload your data to the cloud but exchanges it directly between your machines. That design removes storage limits and monthly fees: the only cap is the disks you own. Every connection uses TLS with perfect forward secrecy, and only devices you approve by their cryptographic ID can join. Setup happens in a browser interface, and the project says it works over a LAN and over the internet without fiddling with IP addresses, falling back to volunteer relays that cannot read your data. The trade-offs are real. There is no official iOS app, pairing devices and sharing folders takes more clicks than signing into Dropbox, and a laptop that is switched off cannot hand over its latest edits. For desktops, laptops, a home server or a NAS, it is the best free choice.

FreeFileSync is the best tool on this list for the drive side of the job: keeping a folder on your computer matched to an external disk, a USB stick or a network share. Its homepage explains that instead of copying every file every time, it works out the differences between a source and a target folder and transfers only what changed. You choose two folders, compare, pick a sync mode and press Synchronize, which makes it easy to see what will be overwritten or deleted before anything happens. The software runs on Windows, macOS and Linux, and version 14.13 shipped on October 16, 2026. Private individuals can use the standard version free. Donors get a Donation Edition with an auto-updater, parallel file copy, email notifications and a portable zip. The FAQ is firm that businesses, organizations and government agencies must buy the Business Edition, which is licensed per device and priced in euros. It is not a continuous background syncer like Syncthing, so pair it with a scheduler if you want hands-off runs.

Resilio Sync Home gives you much of what Syncthing does with a more consumer-friendly app. Resilio describes it as personal file sync and share powered by P2P, so folders move directly between your devices rather than through a cloud account. The big change is pricing: Resilio now says the free Sync download includes all the premium features that used to require a Sync Pro plan. That puts Selective Sync, which creates searchable placeholder files and downloads only what you open, in front of every home user, along with Advanced Folders for changing ownership and read or write permissions and bandwidth limits for slower connections. You can also send big files to friends without sharing a whole folder. The caveats: sync only happens while devices are online together, the company's main business is now its enterprise platform under Nasuni, and business users are pointed to a separate enterprise product with quoted pricing. For home users who want phone apps and placeholders, it is an easy pick.

Google Drive for desktop is the simplest way to keep folders in sync across computers if you already live in a Google account. Google's help center explains the core choice: streaming a file uses almost no computer space, while mirroring downloads a full copy directly to your computer. Beyond the Drive folder itself, you can sync more folders on your computer with Google Drive, so a Documents or Desktop folder on one PC becomes available on another and in the browser. Google also notes that shared files you sync can fill your hard drive but never count against your Google storage. Installation is covered for Windows and macOS. The free tier is the usual 15 GB shared across Gmail, Drive and Photos, and the US App Store listing shows 100 GB for $1.99 and 200 GB for $2.99 through Google One. The catch for a sync tool is that everything travels through Google's servers, so it is a cloud sync service rather than direct sync between your machines, and it cannot target an external drive the way FreeFileSync can.

OneDrive is the default sync service for most Windows PCs, which is its biggest advantage: there is nothing to install on Windows, and signing in with a Microsoft account puts your files on every device. Microsoft's App Store listing says OneDrive keeps your photos and files backed up, protected, synced and accessible on all your devices. The feature list covers version history on all files, a Personal Vault that asks for identity verification, password-protected or expiring sharing links, and ransomware detection and recovery, with an asterisk marking features that need a paid plan. It works closely with Word, Excel, PowerPoint and OneNote for real-time co-editing. Pricing is low: the US App Store shows Microsoft 365 Basic at $1.99, and Microsoft 365 Personal adds 1 TB plus the full Office apps. As with Google Drive and Dropbox, OneDrive syncs through the cloud rather than directly between machines and does not mirror to an external drive, so pair it with FreeFileSync if you also keep drive backups.

Dropbox is still the reference for a sync folder that just works. Install the desktop app, sign in, and anything in the Dropbox folder appears on your other computers and phones. The plans page lists the Plus plan for one person with 2 TB of storage, 30 days to restore deleted files and transfers up to 50 GB, while Standard for teams starts at 3 TB with 180 days of recovery and Advanced adds end-to-end encryption and single sign-on. The free Basic plan gives 2 GB, which is fine for testing but too small for most real folders. Pricing is where Dropbox loses ground for this use. The US App Store listing shows Dropbox Simple at $6.99 a month and Plus at $11.99 a month, both well above Google One and Microsoft 365 Basic for entry storage. Like the other cloud options, Dropbox copies every file through its own servers and does not sync to an external drive. Choose it when its recovery windows and team features matter more than price.

ChronoSync is the most complete sync tool here for Mac owners. Econ Technologies sells it as an all-in-one app for incremental and bi-directional file and folder syncs, incremental and bootable backups, and compatibility with iCloud and other cloud services. The classic use the vendor describes is matching an office desktop with a travel laptop before you leave and again when you return. You can schedule tasks at almost any interval, drill into the folder tree to control exactly what will happen, and preview the results before committing. Targets include external drives, remote Macs running ChronoAgent, SFTP servers, and cloud services such as iCloud, Dropbox, Amazon and Backblaze. The license is $49.99, there is a free trial with no credit card, and the vendor says it has updated the app over 70 times since 2002 without charging an upgrade fee. It needs macOS 10.14 or newer, so it is no help on Windows or Linux, and it takes longer to learn than Dropbox.

Rclone is the power tool of this list. Its site describes it as a command-line program to manage files on cloud storage, with support for over 70 products including S3 object stores, consumer services such as Google Drive, OneDrive, Dropbox and Proton Drive, and protocols such as SFTP, WebDAV and SMB. The sync command makes a destination match a source, and bisync keeps two directories in sync in both directions. Rclone preserves timestamps and verifies checksums, can restart interrupted transfers from the last good file, and uses server-side copies between providers where possible so data does not pass through your machine. It can also mount any local or cloud file system as a disk on Windows, macOS, Linux and FreeBSD, and wrap remotes with encryption or compression. It is free, open source software written in Go. The obvious limit is ease of use: you work at the command line or through scripts and its API, so it suits people comfortable with a terminal rather than someone who wants a sync folder.

SyncBack is a long-running Windows family with three editions. 2BrightSparks describes SyncBackFree as a simple backup and restore solution at no cost that needs no email registration, while SyncBackSE and SyncBackPro add intelligent sync, fast backup and more advanced options. Pro is the version for sync across the cloud: it supports Amazon S3 compatible services, Google Drive, OneDrive, SharePoint, Dropbox, Box, Backblaze B2, pCloud, Cloudflare R2 and WebDAV, plus SFTP and FTP, versioning with delta copy, and S.M.A.R.T. and ransomware detection. SyncBack Touch, free with V12, extends backups to macOS, Linux and Android devices. Paid editions use a perpetual license that never expires, with minor upgrades free and major upgrades charged, and a home license covers up to five devices. The interface shows its depth, so expect a learning curve. We could not confirm US dollar prices because the web store showed local currency from our location, so check the store before buying.