Is it a Virus?
✔ NO - Safe
Must be located in C:\Program Files\FastStone Image Viewer\FSViewer.exe or C:\Program Files (x86)\FastStone Image Viewer\FSViewer.exe
Warning
Typically a single main process
FastStone Image Viewer commonly runs as one primary process with auxiliary threads for rendering previews and applying edits
Can I Disable?
✔ YES
Close the viewer or disable startup in Task Manager to prevent auto-launch
What is faststone-exe?
faststone-exe is the executable that launches FastStone Image Viewer, a fast, lightweight image viewer and organizer. It opens images, provides viewing and editing tools, and manages a library with thumbnail previews and batch operations.
FastStone Image Viewer uses a GUI process with background tasks for thumbnail generation and editing operations, relying on Windows graphics APIs to render images efficiently while keeping the interface responsive.
Quick Fact: FastStone Image Viewer emphasizes speed and simplicity, using a single primary executable with modular components for view, edit, and batch tasks.
Types of FastStone Processes
- Main GUI Process: Handles the primary window, menus, and user interactions (FSViewer.exe)
- Thumbnail/Preview Renderer: Background thread(s) generating image thumbnails for quick browsing
- Editing Engine: Applies rotations, crops, color adjustments in a separate worker context
- Batch Processor: Executes batch conversions and exports without blocking the UI
- Library Scanner: Indexes folders to enable fast search and thumbnail updates
- Clipboard/Export Helper: Manages copy-to-clipboard tasks and export operations
Is faststone-exe Safe?
Yes, faststone-exe is safe when it is the legitimate file from FastStone Soft downloaded from official sources (faststone.org or official installers).
Is faststone-exe a Virus or Malware?
The real faststone-exe is NOT a virus. However, malware sometimes disguises itself with similar names.
How to Tell if faststone-exe is Legitimate or Malware
- File Location: Must be in C:\Program Files\FastStone Image Viewer\FSViewer.exe or C:\Program Files (x86)\FastStone Image Viewer\FSViewer.exe. Any faststone-exe elsewhere is suspicious.
- Digital Signature: Right-click FSViewer.exe in its folder → Properties → Digital Signatures. Should show "FastStone Soft" as the signer.
- Resource Usage: Normal usage is 2-15% CPU and 60-250 MB memory during typical use. Constant high usage when idle is suspicious.
- Behavior: The program should launch when you start FastStone Image Viewer and should not continuously spawn multiple unrelated processes.
Red Flags: If faststone-exe is located in unusual folders (Temp, AppData, System32), runs when you are not using FastStone, has no valid signature, or uses persistent high resources, scan with antivirus and verify with the vendor.
Why Is faststone-exe Running on My PC?
faststone-exe runs when you open FastStone Image Viewer or when background features such as thumbnail indexing and library monitoring are enabled.
Reasons it's running:
- Active Image Viewing: You're currently viewing images; the viewer loads previews and renders edits in real time.
- Background Library Monitoring: FastStone may monitor watched folders to refresh thumbnails and search results.
- Batch Processing: Starting batch conversions or exports runs a separate thread to handle tasks without freezing the UI.
- Startup Launch: If configured, FastStone Image Viewer launches automatically when Windows starts.
- Thumbnail Cache Maintenance: Background tasks refresh and cache image thumbnails to speed up browsing.
Can I Disable or Remove faststone-exe?
Yes, you can disable faststone-exe. It is safe to close the viewer, and you can uninstall or disable startup to prevent automatic launches.
How to Stop faststone-exe
- Close the Viewer: Click the X or use File → Exit to close FastStone Image Viewer
- End Background Tasks: Open Task Manager (Ctrl+Shift+Esc), locate FSViewer.exe, and End Task
- Disable Startup: Task Manager → Startup tab → Disable FastStone Image Viewer
- Disable Background Features: In FastStone, go to Settings → Performance and disable library monitoring or background exports
- Uninstall: Windows Settings → Apps → FastStone Image Viewer → Uninstall
How to Uninstall FastStone Image Viewer
- ✔ Windows Settings → Apps → Apps & Features → FastStone Image Viewer → Uninstall
- ✔ Control Panel → Programs → Uninstall a program → FastStone Image Viewer → Uninstall
- ✔ After uninstall, consider alternative viewers like IrfanView or XnView
Common Problems: Slow Startup or High Resource Usage
If faststone-exe is consuming disproportionate resources or failing to respond, try targeted fixes below.
Common Causes & Solutions
- Large image libraries: Index large folders selectively and avoid scanning entire drives; disable automatic folder scanning in settings.
- Low thread priority during rendering: Ensure the viewer is allowed to use CPU cores; update to latest version which optimizes rendering.
- Outdated codecs or image formats: Update FastStone to the latest build which improves RAW and codec support.
- Corrupted thumbnail cache: Clear thumbnail cache from Settings → Performance → Clear Thumbnails
- Background tasks enabled unnecessarily: Disable background exports and library monitoring to reduce background activity
- Insufficient permissions: Run FastStone Image Viewer as Administrator or adjust folder permissions where images reside
Quick Fixes:
1. Update FastStone Image Viewer to the latest version
2. Clear thumbnail cache: Settings → Performance → Clear Thumbnails
3. Close unused images and close the viewer to test load
4. Disable unnecessary background features in Settings
5. Run as Administrator if permission issues occur
Frequently Asked Questions
Is faststone-exe a virus?
No, the legitimate faststone-exe from FastStone Soft is not a virus. Verify the file path (C:\Program Files\FastStone Image Viewer\FSViewer.exe or C:\Program Files (x86)\FastStone Image Viewer\FSViewer.exe) and ensure a valid digital signature from 'FastStone Soft'.
Why is faststone-exe using so much memory?
Memory usage can spike when viewing or editing very large images, or when the library index is rebuilding. Close unnecessary images, update to the latest version, and limit active folders in library monitoring.
Can I disable faststone-exe from starting automatically?
Yes. Use Task Manager → Startup tab to disable FastStone Image Viewer, or disable background features in the app's Settings.
How do I uninstall FastStone Image Viewer?
Open Windows Settings → Apps → Apps & Features → FastStone Image Viewer → Uninstall. You can also use Control Panel → Programs → Uninstall a program.
How do I update FastStone Image Viewer?
Open FastStone Image Viewer, choose Help → Check for Updates, or download the latest installer from the official FastStone website and install over the existing version.
Does faststone-exe run in the background after I close the window?
Typically no, unless you enabled background tasks like 'Continue running in background' in the app settings. Disable that option to ensure it terminates completely on exit.