SyncToy — Microsoft's Free Sync Tool, So Simple It Needs No Manual
In a nutshell: A free folder synchronization tool from Microsoft offering three sync modes (Sync/Echo/Contribute) — suitable for syncing files between local disks, USB drives, and network shares. Extremely simple to operate, but Microsoft has discontinued updates (not recommended for new computers).
Do You Also Have the Need to “Sync Two Folders”?
Scenario One: You have a USB drive, and the files on it need to stay in sync with your “Work Documents” folder on your computer. But as you plug and unplug the USB drive, you can’t tell which side has the latest files. You end up selecting all and copy-pasting — slow and prone to duplicates.
Scenario Two: You have a laptop and a desktop that share folders over the local network. You modify a file on your laptop and want the corresponding folder on your desktop to update automatically. You don’t want to manually check each file.
Scenario Three: You keep important photos in “D:\Photos\2025” and want to regularly back them up to an external hard drive, but you only want to copy “new and modified files” without doing a full copy every time.
SyncToy was designed precisely for these “folder-to-folder” sync needs. It’s not as complex as professional backup tools. It doesn’t even need to be installed — just download, extract, and use.
What Does SyncToy Do?
SyncToy is a free folder synchronization tool released by Microsoft in 2009 (part of the Microsoft PowerToys series, but the newer PowerToys no longer includes SyncToy). What it does is simple: sync the contents of one folder to another.
SyncToy has three sync modes, each for different use cases:
- Sync: Bidirectional sync, both sides always保持一致
- Echo: Unidirectional sync, new/modified files on the left are copied to the right
- Contribute: Similar to Echo, but does not delete files in the target folder
SyncToy’s interface is very intuitive — it displays source and destination with two large folder icons, with an arrow between them showing the sync direction. Before each operation, it shows a “list of operations to be performed” so you know exactly which files will be copied, updated, or deleted.
Core Features
1. Three Sync Modes — Covering Common Scenarios
| Mode | Direction | Behavior | Use Case |
|---|---|---|---|
| Sync | ↔ Bidirectional | Keeps both sides consistent, both can add/modify, sync renames | Computer ↔ USB, Laptop ↔ Desktop |
| Echo | → Unidirectional | Left new/modified → copied to right. Right-side changes don’t affect left | Backup documents to external hard drive |
| Contribute | → Unidirectional (Safe) | Like Echo, but does not delete any files in the target folder | Final archive backup, photography portfolio archive |
A practical example:
- Sync mode: Your work folder is at “C:\Work” and there’s a copy on your USB drive. You change a file on your computer → run SyncToy → the corresponding file on the USB drive updates. Conversely, if you change a file on the USB drive, the computer syncs as well.
- Echo mode: Your “My Documents” needs daily backup to the D drive. Run Echo mode → new files are copied to D drive, modified files overwrite old versions on D drive. But if you accidentally delete a file from “My Documents,” the corresponding file on D drive will not be deleted.
- Contribute mode: Your photography work needs archiving to an external hard drive. After each shoot → run Contribute mode → new/modified photos are copied to the external drive. But files already existing on the external drive are never deleted.
2. Preview Sync Operations — See the “Consequences” Before Executing
This is SyncToy’s most thoughtful design:
Before actually syncing, SyncToy scans the differences between both sides and lists all operations that will be performed:
📋 Preview Results:
Copy new files: 23
Update existing files: 5
Rename files: 2
Delete files: 0
Total: 30 operationsYou can review each operation — confirm they’re correct and click “Run” to execute. If something seems wrong (e.g., it wants to delete a file you want to keep), you can cancel and adjust settings.
3. Multiple Folder Pairs — Manage Multiple Sync Tasks
You can create multiple pairs, each with its own source folder, target folder, and sync mode. For example:
| Pair Name | Source Folder | Target Folder | Mode |
|---|---|---|---|
| Work Documents Backup | C:\Work | D:\Backup\Work | Echo |
| Photo Archive | C:\Photos | E:\ExternalHDD\Photos | Contribute |
| USB Sync | C:\Documents | F:\ (USB)\Documents | Sync |
Each pair can be executed individually or all together.
Professional Media and User Reviews
| Source | Review |
|---|---|
| TechSpot | ”SyncToy is a simple, effective file synchronization tool from Microsoft — it does one thing and does it well” |
| How-To Geek | ”A handy free tool that makes folder synchronization on Windows easy, even if it shows its age in terms of design” |
| CNET | ”If you need a straightforward way to keep folders in sync without complex setup, SyncToy is worth a look” |
What Real Users Say
“I’ve been using SyncToy for over a decade. Its biggest advantage is simplicity — ‘left is source, right is target, choose direction, click run.’ Unlike other备份 software with dozens of settings that are overwhelming. Even though Microsoft stopped updating it long ago, it still works on Windows 10.” — IT Operations, 知乎
“SyncToy’s preview feature is really useful — it shows you the list of additions, deletions, and changes before each run, so you can confirm before executing. This kind of design is actually harder to find in today’s ‘one-click sync’ tools. The interface may be ugly, but the logic is clear.” — Software Engineer, V2EX
“Honestly, in 2025, SyncToy is indeed old. Microsoft stopped maintaining it long ago, and FreeFileSync has surpassed it in both features and speed. But SyncToy’s sync mode design (Sync/Echo/Contribute) is still textbook-worthy — simple and intuitive, easy to understand at a glance.” — Project Manager, SegmentFault
Comparison with Similar Tools
| Dimension | SyncToy | FreeFileSync | GoodSync | Robocopy (Command Line) |
|---|---|---|---|---|
| Price | Completely free | Completely free | Free/Pro $29.95 | Built-in free |
| Interface | ⭐⭐⭐ Simple and intuitive | ⭐⭐⭐⭐ Modern | ⭐⭐⭐ Traditional | ❌ No GUI (command line) |
| Sync Modes | ⭐⭐⭐ 3 modes | ⭐⭐⭐⭐⭐ Many | ⭐⭐⭐⭐⭐ Rich | ⭐⭐⭐ Basic mirror |
| Preview | ✅ Detailed list | ✅ Detailed list | ✅ Detailed list | ✅ /L parameter preview |
| Real-time Sync | ❌ No | ❌ Manual trigger | ✅ Supported | ❌ No |
| Performance (Large Files) | ⭐⭐ Slower | ⭐⭐⭐⭐⭐ Fast | ⭐⭐⭐⭐ Fast | ⭐⭐⭐⭐⭐ Fastest |
| Incremental Backup | ⭐⭐⭐ Basic | ⭐⭐⭐⭐⭐ Version management | ⭐⭐⭐⭐ Good | ⭐⭐ Basic |
| Network Folders | ✅ Supported | ✅ Supported | ✅ Supported | ✅ Supported |
| Microsoft Maintenance | ❌ Discontinued | N/A (Third-party) | N/A (Third-party) | ✅ System built-in |
| Portable Version | ❌ No | ✅ Yes | ✅ Yes | N/A |
Selection advice:
- 2025 recommendation: Skip SyncToy, use FreeFileSync. SyncToy was a good choice in 2009, but Microsoft stopped updating it long ago. FreeFileSync is its best replacement — free, continuously updated, more feature-rich, and faster.
- If you must use a Microsoft official tool → use Robocopy (command line, system built-in, powerful but requires learning command parameters)
Download and Installation Guide
Important Note
⚠️ SyncToy has been discontinued: Microsoft stopped updating SyncToy after releasing version 2.1 in 2009. Although it still runs on Windows 10/11, it may not be compatible in the future.
The official download page (Microsoft Download Center) no longer offers this tool. If downloading from third-party sites, please be cautious about safety — it’s recommended to scan with antivirus software before running.
Strongly recommended alternatives: Consider FreeFileSync (free, continuously updated, more powerful) or Windows’ built-in Robocopy (command line, stable and reliable).
Frequently Asked Questions
Q: Is SyncToy still worth using? A: Not worth installing on new computers. This tool stopped updating in 2009. Although it’s still compatible with Windows 10/11, its performance and stability are inferior to modern tools. FreeFileSync is the recommended replacement.
Q: What are SyncToy’s disadvantages compared to FreeFileSync? A: Three main areas: ① Speed — SyncToy is 3-5x slower than FreeFileSync when handling many small files; ② Features — SyncToy only has 3 modes, FreeFileSync offers Mirror/Update/Bidirectional/Custom and more; ③ Updates — SyncToy hasn’t been updated since 2009, FreeFileSync is continuously updated through 2025.
Q: I just want a simple folder sync. Besides SyncToy, what are my options? A: Three options: ①FreeFileSync (the most feature-rich free sync tool, highly recommended); ②Robocopy (Microsoft’s official command-line tool, stable and reliable, but you need to learn parameters); ③OneDrive/Cloud Sync (if you’re just syncing between your own computers, cloud sync is the most hassle-free solution).
SyncToy was a good introductory file sync tool in 2009 — with three simple sync modes, it helped ordinary people understand the concept of “folder synchronization.” But in 2025, it’s already a legacy tool. Understanding its three sync modes (Sync/Echo/Contribute) can help you understand file sync logic, but for actual use — please use FreeFileSync.