PDF Steganography Hider
Hide secret text or files inside PDF documents using advanced steganography algorithms. AES-256 encrypted, 100% client-side.
Drop PDF here or click to browse
Accepted: PDF | Max: 200 MB
100% Client-Side Processing
Your PDF never leaves your device. All processing happens in your browser.
How to Hide Data in a PDF (5 steps)
- Upload your PDF file as the carrier
- Type your secret message or upload a file to hide
- Choose an embedding algorithm (Metadata is recommended)
- Add a password to encrypt the payload (optional)
- Click Encode — download your stego PDF
5 PDF Embedding Algorithms
| Algorithm | Technique | Stealth | Best For |
|---|---|---|---|
| Metadata Embedding | XMP / Info dictionary keys | 🔴 Low | Quick demos, high capacity |
| Whitespace Encoding | Inter-word spacing tweaks | 🟢 High | Text-heavy PDFs |
| Invisible Text Layer | Zero-size / transparent text | 🟡 Medium | Standard use |
| Object Stream Padding | Hidden bytes in content streams | 🟡 Medium | Binary payloads |
| Font Encoding | Glyph substitution tables | 🟢 High | Maximum stealth |
Frequently Asked Questions
Will the PDF look different after encoding?
No. The encoded PDF is visually identical to the original. All methods operate below the visible threshold.
Is my PDF uploaded to a server?
Never. All processing happens entirely in your browser. Your PDF never leaves your device.
Does this work with scanned PDFs?
Partially. Scanned PDFs support Metadata and Object Stream methods, but not Whitespace or Font Encoding which require editable text.
Will encoding break digital signatures?
Yes. Any modification to a digitally signed PDF will invalidate the signature. Encode before signing.
How much data can I hide?
Depends on PDF size and algorithm. Metadata and Invisible Text offer high capacity; Font Encoding is lower but harder to detect.