1ST File Viewer Online
Open and preview .1st files (1ST File) directly in your browser — no downloads, no installs, no account required.
Open 1ST File Now →About 1ST Files
| Extension | .1st |
| Full Name | 1ST File |
| MIME Type | application/octet-stream |
| Category | 📄 Documents |
| Processing | 🔒 In-browser (private) |
How to Open 1ST Files Online
- Visit ViewAnyFile.app
Go to ViewAnyFile.app in any web browser.
- Upload your 1ST file
Drag and drop your
.1stfile, or click to browse. - View instantly
Your file renders immediately. It stays in your browser — nothing is uploaded.
Frequently Asked Questions
How do I open a 1ST file online?
Visit ViewAnyFile.app and drag your .1st file into the upload area. It renders instantly — no download or account needed.
Is it safe to open 1ST files on ViewAnyFile.app?
Yes. All processing for 1ST files happens entirely inside your browser. Your files never leave your device and are never uploaded to any server.
Can I open 1ST files on Mac and mobile?
Yes. ViewAnyFile.app works in any modern browser on Windows, macOS, Linux, iPhone (Safari), and Android (Chrome). No operating system restrictions.
Do I need to create an account?
No. ViewAnyFile.app is 100% free with no signup required. Just drag, drop, and view.