PDF Studio

The complete PDF toolkit for Android: 68 tools, fully offline, free forever. Read, annotate, sign, merge, split, compress, convert, protect, scan and OCR, and your documents never leave your phone.

Download APK · Features · Screenshots · Build from source · Contributing

---

✨ Why PDF Studio?

Most PDF apps upload your files to a server, show ads, or lock basic tools behind a subscription. PDF Studio does none of that.

🔒 Private by design	Every tool runs on your device, including OCR, barcode reading and signature checks. Your documents are never uploaded.
⚡ Fast	Most PDFs open without a full parse, and reopening a file is instant.
🧰 68 tools in one app	Viewer, editor, converter, scanner, OCR, security and forms, so you don't need 10 separate apps.
🎨 Modern Material You design	Built with Jetpack Compose and Material 3: dynamic colour, dark mode and tablet layouts.
💸 Free & open source	MIT-licensed, no ads, no account, no paywall.

---

📱 Screenshots

Home	All tools	Files

PDF reader	Tools	Settings

Home-screen widgets

---

🚀 Features

📖 Smart PDF reader

• Pinch and double-tap zoom with a focal point, continuous or single-page mode
• Night and sepia reading themes, full-screen mode and a page scrubber
• Full-text search, and it reopens each PDF where you left off
• Open PDFs from any app through Open with or the Share sheet

🧰 68 tools in 11 categories

📄 Basics (7 tools)

Open PDF · Images to PDF · Scan Document (auto-crop) · Blank PDF · Print PDF · PDF Properties · Edit Metadata

🗂️ Pages (11 tools)

Merge PDFs · Split PDF (by range, every N pages, or selected pages) · Organise Pages (drag to reorder) · Rotate · Delete · Duplicate · Add Blank Pages · Extract · Insert from PDF · Replace Pages · Move Between PDFs

✍️ Edit & Annotate (7 tools)

Annotate & Draw (pen, shapes, highlights) · Sign PDF · Add Text · Highlight / Underline / Strike · Comments & Sticky Notes · Stamps & Dates · Add Image / Logo

🔄 Convert (6 tools)

PDF → Images (PNG/JPG) · PDF → Text · Text → PDF · Markdown → PDF · HTML → PDF · Saved Webpage → PDF

🗜️ Compress (3 tools)

Compress PDF · Image Quality (resolution & JPEG quality) · Remove Metadata

🔐 Security (3 tools)

Add Password (AES-256) · Remove Password · Permissions (restrict print, copy, edit)

🔍 OCR & Scan (5 tools)

OCR → Searchable PDF · Extract Scanned Text · Auto Orientation · Deskew Scans · Remove Blank Pages

🔖 Organise (7 tools)

Bookmarks · Table of Contents · Page Labels (i, ii, iii… A-1…) · Header & Footer · Page Numbers · Watermark (text or image) · Bates Numbering

🔎 Search & Text (3 tools)

Search & Highlight · Word Count · Find & Replace

🖼️ Page & Image (4 tools)

Crop Pages (manual or auto) · Resize Pages (A4, Letter, custom) · Grayscale · Embedded Images (extract, replace, remove)

🧪 Advanced (12 tools)

Redact · Find Sensitive Info (emails, phones, card numbers, IDs, then redact) · Fill Form · Create Form · Flatten · Verify Digital Signatures · PDF/A (validate & convert) · Find Duplicate Pages · Detect Blank Pages · QR & Barcode Reader · Batch Process · Repair PDF

📂 Built-in file manager

• Every PDF on your phone in All, Saved by app and Recent tabs, with folder paths
• Sorting, multi-select, rename, delete and quick preview
• Storage view that shows PDF space by folder and finds duplicate copies

🧩 Home-screen widgets

• PDF Studio (4×2, resizable): Open, Scan, Merge and Compress in one tap
• Dashboard (4×3): eight quick tools plus your last file
• Recent PDFs (4×3, scrollable): reopen recent files instantly
• Quick Tool (1×1): a shortcut to any tool you choose

---

🛡️ Privacy

• ✅ All processing happens on-device, including OCR (Google ML Kit on-device models).
• ✅ No account, no ads, no analytics on your documents.
• ✅ Files you create stay in PDF Studio's folder until you save or share them.
• ✅ Fully open source, so you can read every line of code yourself.

---

📥 Download

1. Go to the latest release.
2. Download PDF-Studio-v2.2.0.apk.
3. Open it on your phone and allow Install unknown apps when Android asks.

Requirements: Android 7.0 (API 24) or newer, on an ARM phone or tablet (arm64-v8a / armeabi-v7a).

---

🛠️ Tech stack

Layer	Technology
Language	Kotlin 2.2 + Coroutines
UI	Jetpack Compose, Material 3, Material You dynamic colour
PDF engine	PdfBox-Android + Android PdfRenderer
OCR & scanning	Google ML Kit: text recognition, barcode scanning, document scanner
Navigation	Navigation Compose
Widgets	AppWidgetProvider + RemoteViews
Build	Gradle (Kotlin DSL), version catalog, R8 minification & resource shrinking
Testing	JUnit, Robolectric, Roborazzi screenshot tests

---

🏗️ Project structure

app/src/main/java/com/example/
├── core/            # PDF engine: page, text, image, OCR, security, forms, conversion ops
├── navigation/      # NavHost, tab routes, adaptive navigation rail
├── tools/
│   ├── settings/    # Settings screen
│   ├── viewer/      # PDF reader
│   └── webview/     # Offline HTML rendering
├── ui/
│   ├── common/      # Shared Compose components
│   ├── editor/      # Annotation & signature editor
│   ├── files/       # File manager, folder browser, storage
│   ├── home/        # Home screen & bottom navigation
│   ├── theme/       # Material 3 theme, colours, typography
│   └── tools/       # Tool catalog and all 68 tool screens
├── utils/           # File & PDF helpers, PDF index
└── widget/          # Home-screen widgets

---

🧑‍💻 Build from source

Prerequisites: Android Studio (latest stable) and JDK 17+.

# 1. Clone
git clone https://github.com/prajwal032004/pdf-studio.git
cd pdf-studio

# 2. Build a debug APK
./gradlew assembleDebug          # Windows: gradlew.bat assembleDebug

# 3. Install on a connected device
./gradlew installDebug

The APK is written to app/build/outputs/apk/debug/.

Signed release build

Release signing keys are never stored in the repository. To sign with your own key:

# Create a key once
keytool -genkeypair -v -keystore my-upload-key.jks -keyalg RSA -keysize 2048 -validity 10000 -alias upload

# Copy the template and fill in your passwords
cp keystore.properties.example keystore.properties

./gradlew assembleRelease

You can also use the environment variables KEYSTORE_PATH, STORE_PASSWORD, KEY_ALIAS and KEY_PASSWORD, which is handy for CI. If neither is set, the release build is signed with the debug key so it still installs for testing.

---

🗺️ Roadmap

• F-Droid and Google Play releases
• More languages
• PDF → Word / Excel export
• Side-by-side PDF compare
• Cloud-free sync between your own devices

Have an idea? Open a feature request.

---

🤝 Contributing

Contributions are very welcome, whether it's a bug report, a new tool, a translation or a UI polish.

1. Fork the repository
2. Create a branch: git checkout -b feature/amazing-tool
3. Commit your changes: git commit -m "Add amazing tool"
4. Push: git push origin feature/amazing-tool
5. Open a Pull Request

Please keep every feature offline: PDF Studio never uploads user documents.

---

⭐ Support the project

If PDF Studio saves you time, please give it a star. It helps other people find the app.

---

📄 License

PDF Studio is released under the MIT License.

It uses these open-source libraries: PdfBox-Android (Apache 2.0), Jetpack Compose & AndroidX (Apache 2.0), Kotlin Coroutines (Apache 2.0) and Google ML Kit (ML Kit Terms).

---

Made with ❤️ in India by Prajwal A Bhandagi