Simple PDF Viewer & Reader

Contains adsIn-app purchases
Content rating
Everyone
50+
Downloads
Content rating
Everyone
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About this app

Sia PDF Viewer — Fast, Lightweight PDF Reader

Sia PDF Viewer is a clean, lightweight PDF reader built for one purpose: reading PDFs comfortably on your Android device. No bloated
editors, no unnecessary features — just a fast, focused reading experience.

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📖 TWO READING MODES

• Scroll Mode — Continuously scroll through pages like a web page. Perfect for long documents and research papers.
• Swipe Mode — Flip through pages one at a time with natural swipe gestures. Ideal for books, presentations, and focused reading.

Switch between modes anytime with a single tap.

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🔍 INTUITIVE ZOOM & GESTURES

• Pinch to zoom with smooth, responsive animation
• Double-tap to zoom in and out instantly
• Pan freely while zoomed in — scroll vertically and horizontally with natural one-finger gestures
• Zoomed scrolling works seamlessly in both reading modes

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📚 ORGANIZE YOUR LIBRARY

• Create categories and subcategories to organize your PDFs
• Import PDFs from your device using the built-in file picker or open them directly from other apps
• View your library as a list or grid with thumbnail previews
• Sort by name, date added, file size, or last opened
• Search your library by file name
• Track reading progress — see how far you've read at a glance with progress indicators on each book

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🔖 BOOKMARKS & NAVIGATION

• Bookmark important pages for quick access
• Jump to any page instantly with the page slider or direct page input
• Bookmarked pages appear as quick-access chips at the bottom of the screen
• Your reading position is always saved — pick up right where you left off

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🌙 COMFORTABLE READING

• Night mode inverts PDF colors for comfortable reading in the dark — easy on your eyes
• Adjust screen brightness directly from the reader without leaving the app
• Fullscreen immersive mode hides system bars for a distraction-free experience
• Lock screen rotation to stay in your preferred orientation
• Auto-scroll lets you read hands-free at adjustable speeds (0.2x to 3.0x)
• Screen stays awake while you read — no more tapping to keep the display on

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⚡ FAST & EFFICIENT

• Lightweight app with minimal storage footprint
• Smart page caching delivers smooth scrolling even with large documents
• Priority rendering focuses on pages you're actually viewing
• Low-resolution preview during fast scrolling, automatically replaced with full quality when you stop
• Memory-efficient rendering uses half the memory of typical PDF readers

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🎨 PERSONALIZE

• Choose between Light, Dark, or System-follow theme
• Set your preferred default reading mode (scroll or swipe)

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🔒 PRIVACY FIRST

• All your data stays on your device — PDFs, reading history, and settings are stored locally
• No cloud uploads, no tracking, no accounts required
• Full GDPR compliance with transparent data handling
• Delete all your data anytime from Settings

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📤 SHARE & VIEW INFO

• Share PDFs with other apps directly from the reader
• View document details: file name, page count, file size, and your current reading position

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💎 REMOVE ADS

• Sia PDF Viewer is free to use with ads
• A one-time purchase removes all ads permanently — no subscriptions

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Sia PDF Viewer is designed for readers who want a simple, reliable PDF app without the clutter. Whether you're reading textbooks,
research papers, manuals, or ebooks, Sia PDF Viewer gets out of your way and lets you focus on what matters — your content.

Download now and enjoy a better PDF reading experience.
Updated on
Apr 8, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
This app may share these data types with third parties
Location, App activity and 2 others
This app may collect these data types
Location, App activity and 2 others
Data is encrypted in transit
You can request that data be deleted

What’s new

- Debug build icon now shows a DEBUG badge
- Added Google Play in-app review system
- Fixed multiple code quality issues
- Improved accessibility for sliders and scrollbar
- Security: disabled app data backup
- Centralized ad configuration and URL management
Content rating
Everyone
Learn more

App support

About the developer
이장욱
uki0327@gmail.com
죽하로 48 장락주공2단지아파트 209-1003 제천시, 충청북도 27142 South Korea

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