ClearPDF

Project Overview

ClearPDF is an open-source Android document toolkit built with Kotlin and Jetpack Compose, bringing PDF reading and annotation, form signing, Office viewing, XLSX editing, image editing, and document scanning into one app. Most file operations run on-device, and the FOSS build goes online only for the optional Office engine download and web-address conversion. The source is released under the MIT license.

Reading, annotating, signing, and processing documents on your phone.

Key Features

• PDF reading and annotation: continuous scrolling, zoom, and in-document search, with highlights, underlines, strikethroughs, ink, shapes, arrows, and text notes
• Forms and pages: fill PDF forms, flatten fields, and export an annotated copy, plus organize, rotate, delete, and extract pages
• Merge, split, convert: merge, split, compress, encrypt, and decrypt, add page numbers and watermarks, export pages as images, and create PDFs from text or images
• Text and OCR: select and copy text, with on-device OCR for image-only pages
• Office documents: view DOC/DOCX, PPT/PPTX, ODT/ODS/ODP, RTF, CSV, and TXT, with XLSX editable and saveable
• Images and scanning: crop, rotate, straighten, correct perspective, adjust color, apply filters, draw, and remove backgrounds, plus scan multi-page documents to PDF

Target Audience

• Users who handle PDFs on their phone
• Mobile workers who view and annotate office documents
• Android users who value open source and privacy

Quick Start

1. Download the APK matching your device ABI from Releases, for example -arm64-v8a.apk for most devices
2. Open the app and pick a PDF, Office document, or image from the home screen
3. On the reading page, select text, add annotations, or fill in forms
4. To edit a spreadsheet, open an XLSX file, edit cells, and save
5. Download the optional Office engine in settings for better rendering

Core Advantages

• On-device processing: files are processed locally, with no document upload service
• All-in-one: reading, annotation, signing, image editing, and scanning in a single app
• Open and transparent: the source is MIT-licensed, with third-party components and licenses documented

System Requirements

Item	Requirement
OS	Android 6.0 (API 23) or later
Build environment	Android Studio with JDK 17 or newer
Document formats	PDF, DOC/DOCX, XLS/XLSX, PPT/PPTX, ODT/ODS/ODP, RTF, CSV, TXT

Notes

• Only XLSX supports cell editing and saving; other Office formats are view-only
• Word and PowerPoint files are viewed and exported as PDF rather than rewritten in their original formats
• Scanning and background removal are provided by Google Play services and may be unavailable on some devices
• The FOSS build needs network access to download the Office engine and convert web addresses