PDF Toolkit is an open-source, privacy-first PDF editor for Android, written in Kotlin and aimed at anyone who needs to merge, split, compress, convert, annotate, or sign PDF documents entirely on the device, with no internet connection and no account.

What it is

PDF Toolkit is a native Android application distributed under the Apache-2.0 licence. Its interface is built with Jetpack Compose following Material Design 3, and the codebase is organised as MVVM with Clean Architecture. PDF work is handled by PdfBox-Android and the Android PdfRenderer, annotations by a custom Canvas and BlendMode layering, and asynchronous work by Coroutines and Flow; the project builds with Gradle and KSP. It is published on F-Droid, on Google Play, and through GitHub Releases, each through a separate build flavor.

The concrete problem it solves is the routine leakage of private documents to third-party conversion websites and cloud PDF suites. Every operation runs on-device, the app requests no internet permission, and the README states there is no data collection or tracking, no ads, and no analytics in any flavor. That removes the upload step, the account, and the server from ordinary PDF work such as combining scans, shrinking a file for email, or adding a signature.

Key capabilities

• Merge PDF files and images in JPG, PNG, and WebP into one document, with File and Page preview modes.
• Split a PDF into multiple files or specific page ranges, and extract, delete, rotate, or drag-and-drop reorder individual pages.
• Convert images to PDF, PDF pages to JPG, PNG, or WebP images, and scan paper documents to PDF through CameraX with automatic edge detection.
• Annotate with highlight, draw, and markup tools; sign documents, fill PDF forms, and flatten forms and annotations to make them permanent.
• Protect files with password locking, remove passwords when the valid password is known, and apply text or image watermarks.
• Extract text from PDF pages, using ML Kit OCR in the playstore flavor and Tesseract through tesseract4android in the fdroid and opensource flavors.
• Process images directly: compress, resize, convert between JPG, PNG, and WebP, and strip EXIF metadata.

Who uses it and how

• Privacy-sensitive users who cannot upload documents to external servers rely on the absent internet permission and the lack of any account requirement.
• F-Droid users install the fdroid flavor, which pairs Tesseract OCR with no proprietary dependencies or trackers and receives reproducible builds compiled from source.
• Google Play users install the playstore flavor, which uses ML Kit for on-device OCR and ships a smaller APK with no ads and no Firebase.
• Devices without Google Play Services or any connectivity can still run OCR, since the fdroid and opensource flavors keep recognition local.
• Developers build their own copy from the Karna14314/Pdf_Tools repository, choosing the opensource flavor for a fully FOSS binary distributed through GitHub Releases.

Getting started

Install from F-Droid by searching for PDF Toolkit or opening the com.yourname.pdftoolkit package page. To build from source, clone the Karna14314/Pdf_Tools repository and run ./gradlew assembleFdroidRelease, assemblePlaystoreRelease, or assembleOpensourceRelease in Android Studio Hedgehog or newer with JDK 17 and Android SDK 26 or higher.

How it compares

No similar or competing tools are named in the facts supplied for this entry, so PDF Toolkit stands alone in this registry. The only comparison the facts support is internal, between its own flavors: playstore carries ML Kit as its single proprietary dependency, while fdroid and opensource remain free of proprietary dependencies.

When to use it — and when not to

Anyone building or shipping from source must maintain an Android toolchain, specifically Android Studio Hedgehog or newer, JDK 17, and Android SDK 26 or higher, plus Gradle and KSP, so the project suits Android developers rather than server operators. Read the flavor table before choosing, because the playstore build pulls in ML Kit and OCR behaviour differs from the Tesseract builds. One inconsistency worth verifying is the HTML to PDF tool, listed alongside the claim that the app requests no internet permission.

# Clone the repository
git clone https://github.com/Karna14314/Pdf_Tools.git
cd Pdf_Tools

# Play Store flavor (ML Kit OCR)
./gradlew assemblePlaystoreRelease

# F-Droid flavor (Tesseract OCR, no proprietary deps)
./gradlew assembleFdroidRelease

# Opensource flavor (fully FOSS)
./gradlew assembleOpensourceRelease