Frequently Asked Questions

We offer a complete online PDF solution including: 1. PDF Merge - Combine multiple PDF files into one 2. PDF Split - Split large PDFs into smaller files 3. PDF Compress - Reduce file size while maintaining clarity 4. PDF Convert - Convert between PDF and JPG, PNG, Word, etc. 5. PDF Page Management - Delete, extract, rearrange pages 6. PDF Encrypt/Decrypt - Protect or remove PDF passwords All tools work offline, completely free, no registration required.

Yes, 100% completely free! Our promises: • No usage limits - Use as many times as you want • No file quantity limits - Batch processing is completely free • No watermarks - Processed PDFs have no watermarks • No registration required - Open and use, no account needed • Forever free - All basic features remain free forever Supported by the open-source community, making PDF tools truly accessible to all users.

No software installation required! Supported devices: • Desktop: Windows, macOS, Linux • Mobile: iOS (iPhone/iPad), Android • Tablets: All tablet devices Just need a modern browser (Chrome, Edge, Firefox, Safari). The mobile experience is identical to desktop - process PDF files anytime, anywhere.

Merging PDFs is simple, no registration needed: Steps: 1. Click "PDF Merge" tool 2. Drag or click to upload multiple PDF files 3. Adjust file order (optional) 4. Click "Merge" button 5. Download merged PDF file Supports merging 10+ PDF files at once. Files merge in your specified order. The entire process happens locally in your browser, no server upload needed.

Absolutely safe! This is our core promise. Three layers of security: 1. 100% Local Processing • All PDF processing happens in your browser • File data never leaves your device • Works even when offline 2. Zero Server Storage • Our servers cannot see your files • No file uploads, no cloud storage • Browser automatically clears cache after processing 3. Open Source Transparency • Code fully open-sourced on GitHub • Audited by global developers • Supports local deployment Unlike other services requiring file uploads, we use WebAssembly technology for browser-side processing, ensuring your business files and personal privacy are absolutely secure.

We can neither see nor store them! Technical principle: • All processing based on local WebAssembly computation • Files exist only in your device memory • Automatically cleared from memory after processing • Our servers cannot access any file content This means: ✓ Your contracts - Absolutely confidential ✓ Your financial statements - Completely secure ✓ Your personal documents - Will not leak ✓ Your business secrets - Only you can see Even our development team has zero access to any files you process.

The key difference lies in "local processing" rather than "cloud uploading". GuardPDF runs entirely within your browser — no file uploads, no external servers — ensuring complete privacy and security. Key advantages: 1. 🔐 Privacy & Security: All operations happen locally on your device. 2. ⚡ Faster Performance: No upload or download delays. 3. 📁 Large File Support: Handle PDF files up to hundreds of MB (depending on your device). 4. 🌐 Works Offline: Fully functional even without internet access. 5. 💡 Free Forever: All core features are permanently free with no registration or subscriptions. Compared with cloud-based tools, local processing offers superior privacy, speed, and full data control.

All major modern browsers supported: ✓ Fully supported: • Google Chrome 90+ • Microsoft Edge 90+ • Mozilla Firefox 88+ • Apple Safari 14+ • Opera 76+ ✓ Mobile browsers: • iOS Safari (iPhone/iPad) • Chrome for Android • Samsung Internet • UC Browser Recommendation: For best performance, use the latest browser version. If you encounter issues, try updating your browser.

File size mainly depends on your device performance: Recommended limits: • Desktop: Max 200-500MB (depends on memory) • Mobile: Max 50-100MB (avoid lag) • Tablet: Max 100-200MB Actual performance: • Under 10MB: Instant, smooth on any device • 10-50MB: 1-5 seconds, normal on most devices • 50-100MB: 5-15 seconds, needs good device • Over 100MB: Needs high-performance device, may be slow Advantage: Compared to upload services (usually 20-50MB limit), our local processing handles larger files as long as your device has enough memory.

We offer flexible compression options for you to choose: Compression levels: 1. Light Compression (Recommended) • File reduction: 30-50% • Quality retention: 95%+ • Best for: Documents needing high quality 2. Medium Compression • File reduction: 50-70% • Quality retention: 85-90% • Best for: Daily office documents 3. Heavy Compression • File reduction: 70-85% • Quality retention: 70-80% • Best for: View-only documents Other operations (merge, split, convert): • Completely lossless processing • Maintains all original file quality • No clarity reduction or layout changes You can preview before downloading. Unsatisfied? Readjust compression level.

We support multiple resolution options: Available resolutions: • Standard: 150 DPI - Suitable for web display • HD: 300 DPI - Suitable for printing and professional use • Ultra HD: 600 DPI - Suitable for design and publishing Output formats: • JPG - Suitable for photos and color documents • PNG - Supports transparent background, suitable for icons and design • WebP - Smaller file size, same quality Each PDF page converts to a separate image. You can convert all pages or specific pages.

We adopt a tiered transparent strategy: Forever free features (Promise): • PDF merge, split • PDF compress • PDF convert (PDF↔images, Word, Excel) • PDF page management (delete, extract, rearrange) • PDF encrypt/decrypt • All features 100% local processing, no internet needed These core features will never charge! Possible future value-added services (requires user authorization): • AI intelligent summary (requires cloud processing) • AI content translation (requires cloud processing) • OCR text recognition (requires cloud processing) Promise: 1. AI features will clearly inform before requiring upload 2. You can choose not to use and continue enjoying free local features 3. Basic tools remain forever free and locally processed Our philosophy: "Local when possible, cloud with disclosure".