What it is
PaperKnife is a privacy-first PDF utility built with React and TypeScript and distributed as a web application and an Android application. It belongs to the open-source document-management and PDF-tools ecosystem, and its stated architecture is zero-server: documents are processed on the user's device instead of being uploaded to a remote service. Core processing uses pdf-lib and pdfjs-dist in a sandboxed WebAssembly environment, the Android version is powered by Capacitor, and the repository is licensed under AGPL-3.0.
The problem it addresses is the common practice of asking users to upload sensitive PDFs, such as bank statements, IDs, or contracts, to online PDF websites. PaperKnife keeps files in local memory, avoids database storage, and prevents server access during normal use. It works offline, which makes it suitable for people who need routine PDF manipulation without exposing document contents to third-party infrastructure.
Key capabilities
- Merge multiple PDF files into one document.
- Split pages, rotate pages, and rearrange pages within a PDF.
- Reduce file size using different quality presets.
- Encrypt PDFs with passwords or remove password protection locally.
- Convert between PDFs and images in JPG or PNG format, and convert between PDFs and plain text.
- Add an electronic signature to a document without uploading it.
- Sanitize PDF metadata, such as Author or Producer fields, to reduce information leakage.
Who uses it and how
- Android users can install the latest APK from the GitHub releases page or use the linked package repository at apt.izzysoft.de.
- Web users can open the hosted site and use the tools directly in a browser, without uploading files.
- Users can install the web app as a progressive web app for offline access.
- People who handle confidential documents can perform local edits, compression, conversion, signing, and metadata cleanup before sharing files.
- Supporters can sponsor the solo maintainer through GitHub Sponsors or share the project with others who need private PDF tools.
Getting started
Typical methods are downloading the latest Android APK from the GitHub releases page, visiting the hosted web app at https://potatameister.github.io/PaperKnife/, or installing that site as a progressive web app for offline use. The Android package is also available through the linked apt.izzysoft.de repository.
When to use it — and when not to
Use PaperKnife when the priority is keeping PDF contents on the local device while performing common merge, split, compression, encryption, conversion, signing, and metadata tasks. It is a suitable option for individual users and small workflows that need a browser-based or Android-based tool with an AGPL-3.0 license and no server dependency. It may be a poor fit for teams that need hosted collaboration, vendor support, or a large maintainer base, because the project is described as a solo project and currently lists 47 open issues with no contributor count shown.
project readme (upstream, from github) — read inline
PaperKnife
A simple, honest PDF utility that respects your privacy.
Preview
Why I built this
Most PDF websites ask you to upload your sensitive documents—bank statements, IDs, contracts—to their servers. Even if they promise to delete them, your data still leaves your device and travels across the internet.
I built PaperKnife to solve this. It's a collection of tools that run entirely in your browser or on your phone. Your files never leave your memory, they aren't stored in any database, and no server ever sees them. It works 100% offline.
What it can do
- Modify: Merge multiple files, split pages, rotate, and rearrange.
- Optimize: Reduce file size with different quality presets.
- Secure: Encrypt files with passwords or remove them locally.
- Convert: Convert between PDF and images (JPG/PNG) or plain text.
- Sign: Add an electronic signature to your documents safely.
- Sanitize: Deep clean metadata (like Author or Producer) to keep your files anonymous.
How to use it
- On Android: Download the latest APK or get it from:
- On the Web: Visit the live site. You can use it like any other website, or "install" it as a PWA for offline access.
Support the project
PaperKnife is a solo project. It's open-source, ad-free, and tracker-free because I believe privacy is a right, not a luxury.
If this tool has saved you time or kept your data safe, please consider:
- Sponsoring: Support development via GitHub Sponsors.
- Giving a Star: It helps other people find the project.
- Spreading the word: Share it with anyone who handles sensitive documents.
Under the hood
PaperKnife is built with React and TypeScript. The core processing is handled by pdf-lib and pdfjs-dist, which run in a sandboxed environment using WebAssembly. The Android version is powered by Capacitor.
This project is licensed under the GNU AGPL v3 to ensure it remains open and transparent forever.
Made with care by potatameister