Is FastCompressor safe?
Yes. Completely. Here's why you see that warning — and how to fix it.
FastCompressor is a legitimate offline image and video compression tool used by thousands of designers, developers, and content creators. The security warning you see comes from Windows or macOS — not from anything wrong with the app.
Why does my computer say this?
Windows protected your PC
Microsoft SmartScreen flags any app that doesn't have a Microsoft Authenticode code-signing certificate. This certificate costs ~$400/year and requires business verification. The warning has nothing to do with whether an app is safe or unsafe — itonly means the developer hasn't purchased that certificate yet. Even perfectly clean apps get this warning until they do.
What we're doing about it
App built, tested, and distributed directly — zero malware, zero network requests during compression
Apple Developer Program enrollment — complete. App is fully notarised by Apple, removing Gatekeeper warnings.
Microsoft Authenticode code signing certificate — in progress. Removes the Windows SmartScreen warning.
Microsoft Store listing — live. Use the Store download for the smoothest Windows install and updates.
How to open FastCompressor right now
Follow the steps for your operating system below. Each takes less than 30 seconds.
Security warnings are completely normal
Because FastCompressor is downloaded directly from our website instead of an App Store, your computer might show a standard security prompt. Here's exactly how to open it in seconds.
Run the installer (.exe) to see the blue SmartScreen dialog.
Click "More info" (the small text link below the warning).
A "Run anyway" button will appear at the bottom.
Click it, and the installer will proceed normally.
Still in doubt? For complete peace of mind, you can always download FastCompressor directly from the official Microsoft Store.
Why you can trust FastCompressor
Zero network calls
The app processes every file locally. It makes no outbound requests while compressing.
Files stay with you
Nothing is uploaded to any server. You can run FastCompressor in airplane mode.
Real support
FastCompressor is a real product with a real support email and a help center.
Still have questions?
We're a small team and we respond to every email personally. Reach out if you need help getting started.