PDF Vault & Cryptography
Merge, split, reorder and sign PDFs, encrypt any file with AES-256, and turn phone photos into clean scanned documents. Everything runs inside your browser — your documents are never uploaded.
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1 · Draw your signature
2 · Place & stamp
Tap or drag on the page preview to position the signature.
Encrypt any file (PDF, image, document) with AES-256-GCM. The key is derived from your password with PBKDF2-SHA-256 (310,000 iterations) and a random salt. The output is a .nxv vault file that only this page (or any compatible tool) can open — it is not a PDF-reader password.
No file selected.
Lose the password and the data is unrecoverable — there is no backdoor and nothing is stored anywhere.
they become pages of one PDF
No images.
Engineering Breakdown
PDF editing uses pdf-lib: documents are parsed into an object tree, pages are copied between documents with copyPages, rotated with setRotation, and written back out as a new byte stream. Page selections such as 1-3,7,5-4 are parsed into an ordered index list, so extraction, reordering and reversing share one code path. The signature pad records pointer strokes with quadratic smoothing on a transparent canvas, crops the ink to its bounding box, and exports a transparent PNG that pdf-lib embeds; a live page preview rendered with pdf.js lets you place it, and the screen position is converted to PDF coordinates (origin bottom-left) when stamping.
Encryption uses the Web Cryptography API: your password is stretched with PBKDF2-SHA-256 (310,000 iterations, random 16-byte salt) into a 256-bit key, and the file plus its original name are sealed with AES-GCM using a random 12-byte nonce, which also authenticates the data so tampering or a wrong password is detected. The result is a .nxv vault file. Because browser libraries cannot write the PDF standard's own password dictionary, vault files open with this tool rather than in a PDF reader. The scanner converts photos to grayscale, applies contrast and brightness, and for black-and-white mode uses an integral-image adaptive threshold so uneven lighting and shadows turn into crisp text before the pages are embedded as JPEGs.
How to use it in 3 steps
- Open the tab you need and drop your PDFs or images — files are read locally by your browser.
- Arrange the merge order, enter page ranges, draw and position a signature, or set a password and scan filters.
- Download the result: merged PDF, edited PDF, signed PDF, ZIP of single pages, scan PDF or encrypted .nxv vault.
Feature matrix
| Tool | Engine | Output | Notes |
|---|---|---|---|
| Merge | pdf-lib | Reorder, optional metadata clean | |
| Extract / reorder / split | pdf-lib + JSZip | PDF or ZIP | Ranges like 1-3,7; rotate |
| Signature stamp | Canvas + pdf-lib + pdf.js | Signed PDF | Transparent PNG signature |
| AES vault | Web Crypto | .nxv file | AES-256-GCM, PBKDF2 310k |
| Scanner | Canvas + pdf-lib | Adaptive B&W threshold |
Frequently asked questions
Are my PDFs uploaded to a server?
No. pdf-lib, pdf.js and the Web Cryptography API all run in your browser tab. Files are never sent anywhere.
Is the AES encryption the same as a PDF password?
No. It encrypts the whole file with AES-256-GCM into a .nxv vault that you decrypt on this page. A PDF-standard password would not be readable by this approach, but vault files are stronger because the entire file is sealed.
What happens if I forget the password?
The data cannot be recovered. The key is derived only from your password and no copy exists anywhere.
How do I extract specific pages from a PDF?
Load the PDF, type the pages you want such as 1-3,7 and click Build PDF. Typing 3,1,2 reorders pages and 5-1 reverses them.
Can I sign a PDF with a handwritten signature?
Yes. Draw your signature, tap the page preview to position it, adjust the size and download. The signature is embedded as a transparent PNG image.