Introducing PreviewFile.dev
The secure file preview API with password protection, watermarks, and expiration control. Support for 110+ file formats with one simple API call.
The File Sharing Problem
Every day, millions of sensitive files are shared across the internet—contracts, financial reports, design mockups, and confidential documents. Yet most file sharing solutions face the same critical issues:
- No expiration control: Links live forever, creating security risks
- No download prevention: Recipients can easily save and redistribute files
- No watermarking: No traceability when files leak
- Complex infrastructure: Building secure file preview requires months of development
Enter PreviewFile.dev.
What is PreviewFile.dev?
PreviewFile.dev is a secure file preview API designed for developers and SaaS teams who need to share files without losing control. With a single API call, you can:
- Generate secure preview links that expire automatically
- Support 110+ file formats out of the box
- Add password protection, watermarks, and one-time access
- Prevent downloads while still allowing viewing
It's not just a file viewer—it's your complete file security layer.
1. Enterprise-Grade Security, Built-In
Stop reinventing file security. PreviewFile.dev comes with advanced protection features so you can focus on your core product:
- Configurable Expiration: Set links to expire from 1 hour to 7 days
- Password Protection: Require a password to view sensitive files
- Custom Watermarks: Add dynamic watermarks with user info, timestamps, or IP addresses
- One-Time Access: Links that self-destruct after first view
2. Developer-First API Design
# Generate a secure preview link in seconds
curl -X POST https://api.previewfile.dev/preview \
-H "Authorization: Bearer YOUR_API_KEY" \
-F [email protected] \
-F ttl=3600 \
-F password="secret123" \
-F watermark="Confidential"
# Response:
# {
# "preview_url": "https://previewfile.dev/v/xxxx",
# "expire_at": "2026-02-03T14:00:00Z"
# }Our OpenAPI documentation makes integration effortless. Connect to any backend—Node.js, Python, Go, or any language with HTTP support.
3. 110+ File Format Support
No more format headaches. PreviewFile.dev supports:
- Documents: PDF, Word, Excel, PowerPoint, Google Docs
- Images: PNG, JPG, GIF, WebP, SVG, PSD
- Videos: MP4, WebM, MOV, AVI
- Audio: MP3, WAV, OGG, FLAC
- Code: JavaScript, Python, TypeScript, and 50+ languages
- Archives: ZIP preview with file listing
- And more: CAD files, 3D models, eBooks
4. Client-Side Rendering for Maximum Security
Unlike traditional file converters that store rendered files on servers, PreviewFile.dev uses client-side rendering. Your files are:
- Rendered directly in the viewer's browser
- Never stored longer than necessary
- Protected by cryptographic tokens
This means even we can't access your file contents.
Who Uses PreviewFile.dev?
Legal Teams
"We share confidential contracts with clients using one-time links. When negotiations end, the links expire automatically—no cleanup needed."
SaaS Applications
"Our users upload sensitive documents. PreviewFile.dev lets us show previews in our app without exposing the original files or building our own viewer."
Contractors & Freelancers
"I share project deliverables with clients using password-protected links. They can review but not download until payment is confirmed."
HR & Recruiting
"Candidate resumes are viewed through watermarked previews. If anyone leaks them, we know exactly where it came from."
Getting Started
PreviewFile.dev offers a generous free tier perfect for testing and small projects:
| Plan | Preview Count | Link Expiration | Features |
|---|---|---|---|
| Free | 1,000/month | Up to 1 day | Basic watermark |
| Plus | 10,000/month | Up to 7 days | Custom watermarks, password protection |
| Pro | 50,000/month | Unlimited | Advanced analytics, priority support |
| Enterprise | Unlimited | Unlimited | SLA, SSO, on-premise option |
Quick Start
- Sign up at previewfile.dev
- Get your API key from the dashboard
- Make your first API call using the example above
- Integrate into your application
What's Next?
We're just getting started. Here's what's coming:
- ✨ Embed mode: Drop-in
<iframe>component for any website - 🔍 Search within documents: Full-text search in PDFs and Office docs
- 📊 Analytics dashboard: Track views, locations, and access patterns
- 🌐 Regional data residency: EU and APAC data centers
- 🔗 Webhook notifications: Real-time events for file access
Start Protecting Your Files Today
Stop worrying about file security. With PreviewFile.dev, every shared file is under your control—expiring when you want, visible only to who you choose.
What's included in the free tier:
- ✅ 1,000 preview count per month
- ✅ Basic watermarking
- ✅ Up to 1-day link expiration
- ✅ 110+ format support
- ✅ OpenAPI access
- ✅ Community support
Ready to secure your file sharing?