Helpful notes for better studying.
EPUB & PDF · Study · Privacy
Formats & Files
How to Add Books to Your GemReader Library
Bringing your ebooks into GemReader takes only a moment. Learn how to import standalone EPUB, PDF, comic, and archive files directly into your private, local-only bookshelf.
A step-by-step guide on how to import EPUB, PDF, CBZ, and MOBI ebook files into your private GemReader library on Android and iOS.
Read guideFormats & Files
How to Import Books from a ZIP or 7z Archive
Save time when unpacking multi-volume sets or public domain book bundles. Learn how GemReader inspects and extracts books directly from ZIP and 7z archives without cluttering your phone with extra files.
Formats & Files
How to Import Books Shared from Other Apps
Found an interesting book in your browser, a study chat, or your cloud drive? Send it directly to GemReader using your mobile device's system share menu.
Formats & Files
How to Open DRM-Free Kindle Books (MOBI & AZW3)
Have a collection of personal books in Kindle formats? Learn how GemReader parses unprotected MOBI and AZW3 files so you can read them offline with complete typographic control.
Formats & Files
How to Read Comic Books and Manga (CBZ Archives)
Graphic novels and manga deserve an uninterrupted visual presentation. Discover how GemReader handles CBZ comic archives with fluid page turns, double-tap zooming, and tailored controls.
Features & Study
How to Create a Collection (Folder) in GemReader
Organize your growing library into custom shelves and folders. Learn how to create dedicated collections to group your books by genre, course, author, or research project.
Features & Study
How to Rename, Color, and Delete Collections
Tailor your library shelves to match your workflow. Discover how to update folder names, assign vibrant accent colors, and safely delete collections without accidentally removing your books.
Features & Study
How to Organize Books with Nested Collections (Subfolders)
Take deep library organization to the next level. Learn how to create nested subfolders inside your main collections to maintain structured research archives and multi-topic reading lists.
Features & Study
How to Move Books Between Collections in GemReader
Reorganize your shelves with ease. Learn how to move individual titles or entire reading stacks between collections without losing your bookmarks, notes, or reading progress.
Features & Study
How to Favorite Books for Quick Access
Keep your current reads and most treasured references at your fingertips. Discover how to mark titles with the favorite heart icon for instant one-tap filtering in GemReader.
Features & Study
How to Sort and Search Your Library in GemReader
Locate any title in seconds, even in collections of hundreds of books. Master GemReader's real-time offline search and versatile sorting options.
Design Philosophy
How to Switch Between Grid and List Views
Choose the visual presentation that fits your mood and device. Learn how to toggle between full-color cover grids and detailed information rows with precise reading percentages.
Features & Study
How to Manage Multiple Books with Bulk Actions
Organize large libraries in a fraction of the time. Learn how to use GemReader's multi-select tools to move, export, or delete entire stacks of books in a single batch operation.
Features & Study
How to Navigate Pages and Chapters in Ebooks
Master the rhythms of reading in GemReader. Learn about tap zones, swipe gestures, jumping through the Table of Contents, and chapter progress scrubbing for effortless reading.
Design Philosophy
How to Adjust Typography and Reading Fonts in GemReader
Make reading effortless on your eyes. Discover how to customize font families, fine-tune font sizing with smooth sliders, and explore specialized accessibility typefaces like OpenDyslexic and Lexend.
Design Philosophy
How to Choose Reading Themes and Color Palettes
Match your reading display to the light in the room. Discover how to switch between Light, Dark, and System modes in the reader, explore calibrated palettes like Parchment and Velvet, and save OLED battery life.
Design Philosophy
How to Customize Line Spacing, Margins, and Text Alignment
Give your text the exact breathing room it needs. Learn how to adjust line height, side margins, and switch between justified book columns and natural ragged-left alignment in GemReader.
Features & Study
How to Highlight Passages with the Six-Color Palette
Transform reading into active understanding. Learn how to highlight memorable quotes and critical arguments using GemReader's harmonious six-color palette and retrieve them anytime in your Gems Library.
Features & Study
How to Add Notes and Marginalia to Your Highlights
Carry on an active conversation with the author. Discover how to attach personal reflections, study questions, and formatted Markdown notes to your book highlights in GemReader.
Features & Study
How to Set Precision Bookmarks in GemReader
Never lose your exact sentence again. Discover how GemReader's character-level precision bookmarks keep your place intact even when you resize fonts, change screens, or rotate your device.
Features & Study
How to Turn Book Highlights into Spaced Repetition Flashcards
Remember the core insights from everything you read. Learn how to convert your favorite book highlights into memory flashcards powered by the modern FSRS-5 spaced repetition algorithm.
Features & Study
How to Create Cloze Deletion (Fill-in-the-Blank) Cards
Test your memory on specific names, dates, and definitions without losing sentence context. Learn how to craft efficient cloze deletion cards directly from your book passages.
Features & Study
How to Conduct Daily Study Sessions with Spaced Repetition
Build a lasting memory of your reading in just five minutes a day. Learn how to review due flashcards using GemReader's built-in FSRS-5 spaced repetition study engine.
Features & Study
How to Add the Study Widget to Your Android Home Screen
Keep your daily reading and review habits front and center. Learn how to place GemReader's glanceable Study widget on your Android home screen to track due cards and surface inspiring book highlights.
Features & Study
How to Export Flashcards to Anki (.apkg)
Take your learning wherever you study. Learn how to export your GemReader study cards and cloze deletions into standard .apkg deck packages for Anki, AnkiDroid, and AnkiMobile.
Features & Study
How to Import Existing Anki Decks into GemReader
Consolidate your reading and spaced repetition in one quiet sanctuary. Learn how to import your existing Anki .apkg decks into GemReader and review them with modern FSRS-5 scheduling.
Features & Study
How to Tag Highlights and Notes with Hashtags (#Tags)
Weave connections across different authors and genres. Learn how to organize your reading insights with subject tags like #history or #psychology and filter cross-book themes in Library Gems.
Features & Study
How to Browse and Search Your Library-Wide Gems
Your reading highlights deserve a living home. Learn how to search, filter by color or tag, and jump back into original chapters using GemReader's centralized Library Gems.
Design Philosophy
How to Create Styled Excerpt Quote Cards
Share the beauty of literature without clunky screenshots. Learn how to turn profound passages into beautifully formatted quote cards using GemReader's built-in quote sharing tool.
Features & Study
How to Copy Academic Citations (APA, MLA, Chicago, and BibTeX)
Speed up your scholarly research and essay writing. Learn how to generate and copy formatted academic citations directly from book metadata in GemReader.
Features & Study
How to Export Notes and Highlights to Markdown and Obsidian
Connect your reading directly to your personal knowledge graph. Learn how to export book highlights and notes to clean Markdown files with Obsidian wiki-links and tag preservation.
Features & Study
How to Download and Use Offline Dictionaries
Encounter an unfamiliar word without breaking your reading flow. Learn how to download curated offline dictionary packs in GemReader and look up rich definitions anywhere, even with airplane mode enabled.
Design Philosophy
How to Read Multilingual Books with Pinyin and Furigana
Honor the visual heritage of global scripts. Discover how to display pronunciation guides like Pinyin and Furigana, and handle multilingual typography with fidelity in GemReader.
Features & Study
How to Use Offline Read Aloud (Text-to-Speech)
Give your eyes a rest without pausing your story. Learn how to listen to any EPUB or PDF with synchronized sentence highlighting using GemReader's on-device neural text-to-speech engine.
Features & Study
How to Control Audio Speed and Lock-Screen Playback
Tailor your listening pace to your day. Learn how to adjust playback speed without pitch distortion and control narration from your phone's lock screen in GemReader.
Formats & Files
How to Attach Custom Chapter Audio (Audiobook Companion)
Combine the joy of physical reading with professional voice narration. Learn how to pair your own standalone audio files directly to individual chapters of your EPUB books in GemReader.
Formats & Files
How to Read PDFs: Continuous Scroll vs. Two-Page Spreads
Match your PDF layout to the document's design. Learn how to switch between fluid continuous vertical scrolling, traditional single pages, and side-by-side two-page spreads in GemReader.
Features & Study
How to Create and Organize Standalone Notebooks
Give your thoughts room to breathe beyond book margins. Learn how to create dedicated reading journals, research logs, and commonplace notebooks directly inside GemReader.
Privacy & Control
How to Use Gem Beam for Wireless Device-to-Device Sharing
Transfer books, collections, and reading progress directly between devices over high-speed local Wi-Fi without internet access, cables, or cloud accounts.
Privacy & Control
How to Choose What You Share with Gem Beam
Tailor your wireless transfers. Choose whether to beam clean ebook files to a friend or include your personal study notes, audio tracks, and nested shelf structures.
Privacy & Control
How to Create Encrypted GemPack Backups
Protect your digital library and years of annotations. Learn how to package your books, notes, flashcards, and reading statistics into a portable, encrypted .gempack archive.
Privacy & Control
How to Restore Your Library from a GemPack
Transition to a new phone or recover your collection effortlessly. Learn how to unpack a .gempack archive and restore your books, shelves, notes, and reading progress.
Privacy & Control
How to Schedule Automatic Local Backups
Set up hands-free, automated backups of your reading notes, highlights, and library structure to an SD card or dedicated folder on your device.
Privacy & Control
How to Lock Collections with a PIN (Locked Libraries)
Keep private research, personal journals, and sensitive reading material secure behind an encrypted vault protected by a 4-digit PIN.
Privacy & Control
Understanding Intrusion Protection and Crypto-Erase
Learn how GemReader's defense-in-depth security and 3-attempt PIN auto-wipe safeguard your sensitive Locked Libraries against brute-force intrusion.
Privacy & Control
How to Set Up App Lock with PIN and Biometrics
Guard your entire reading sanctuary. Require a master PIN, fingerprint, or facial recognition scan every time GemReader is launched.
Privacy & Control
How to Protect Your Screen from Shoulder Surfing
Read with total peace of mind on crowded subways and flights. Discover Screen Privacy Shield and app switcher masking in GemReader.
Features & Study
How to Browse Public Domain Catalogs with OPDS
Discover tens of thousands of free classic ebooks. Browse and download treasures from Project Gutenberg and Standard Ebooks directly inside GemReader.
Features & Study
How to Add Custom OPDS Catalogs
Connect GemReader to your home Calibre server, Kavita library, or university repository. Download books from your private cloud anytime.
Features & Study
How to Use Dual-Pane Split View on Tablets and Foldables
Double your study productivity. Learn how to open two books side by side or keep an ebook next to your study notes on tablets and foldable screens.
Design Philosophy
How to Read PDFs in Dark Mode Without Inverting Photos
Read white-page PDF documents comfortably late at night. Discover GemReader's intelligent page inversion that darkens stark backgrounds while preserving color photos.
Formats & Files
How to Recognize Text in Scanned PDFs with On-Device OCR
Transform flat, image-only scanned books into interactive text. Extract words, highlight quotes, search for keywords, and listen with Read Aloud entirely on-device.
Design Philosophy
How to Import and Use Custom Fonts
Read in your favorite personal typeface. Learn how to install .ttf and .otf font files into GemReader for reading across all reflowable books.
Privacy & Control
How to Migrate Your Library to an External SD Card
Reclaim precious phone memory. Learn how to safely move your encrypted books, audio companions, and archives to an external micro-SD card.
Features & Study
How to Use Keyboard Shortcuts on Chromebooks and Tablets
Navigate your library and turn pages at the speed of thought. Discover hardware keyboard shortcuts for Bluetooth keyboards, iPad Magic Keyboards, and Chromebooks.
Privacy & Control
How to Create a Privacy-Safe Diagnostics Report for Support
Troubleshoot technical issues without compromising your privacy. Learn how to generate an anonymized, scrubbed diagnostics report to share with support.
Features & Study
Best Free EPUB Readers for iPhone and iPad in 2026 (Honest Picks by Use Case)
Apple Books is already on your iPhone, and for a lot of people it's enough. This guide is for when it isn't: Kindle-format files, comics, a no-ads library, cross-device sync beyond iCloud, or highlights you want to study. Six free apps, what each does best and where each falls short. Written by the makers of one of them, with that bias declared up front.
Features & Study
How to Turn Ebook Highlights into Flashcards on iPhone (3 Ways)
Apple Books keeps every highlight you make and never asks you about one again. Here are three ways to get highlights from an EPUB, PDF or Kindle book into a spaced-repetition deck on iPhone or iPad: the manual Anki route, a paid sync service, and a reader that skips the export entirely.
Formats & Files
How to Open AZW3 and MOBI Files on iPhone (Without the Kindle App)
Tap an AZW3 or MOBI file on an iPhone and Apple Books won't take it. Kindle mostly won't either. Here is why, how to tell in ten seconds whether the file is locked, and which iPhone and iPad readers open the unlocked ones directly.
Features & Study
旁注的艺术：内联脚注、触感引用与阅读心流的守护
探索 GemReader 重塑的脚注体验。了解双引擎内联弹窗卡片、一键触感复制、图形金句卡片分享及双向排版系统如何在深度阅读中守护您的专注心流。
Features & Study
升华边白：结构化 Markdown 与数字批注的艺术
通过完整的 Markdown 语法支持，将零散的批注转化为结构清晰的旁注。在文本高亮、图片笔记与珍藏库中轻松排版标题、列表、引用及超链接。
Privacy & Control
纵深防御：GemReader 多层 PIN 码与窗口安全架构解析
深入探讨 GemReader 如何通过自定义触控按键绕过系统输入法、协同引用计数 FLAG_SECURE 窗口遮蔽以及解密 AES-GCM 书库密钥。
Features & Study
2026年适用于 Android 的最佳免费 EPUB 阅读器（按使用场景客观推荐）
Android 上没有绝对单一的最佳 EPUB 阅读器——只有最适合您阅读习惯的工具。本文盘点了六款免费应用，客观分析各自的优势与不足，并在漫画、电子墨水屏、多端同步、隐私保护和学术研究等场景给出清晰答案。由其中一款应用的开发者撰写，并在此提前声明立场。
Features & Study
如何在 Android 上将电子书高亮转化为闪卡（3 种方法）
在教科书上画线看似收获满满，实则往往徒劳无功——高亮静静躺在那里，你可能再也不会多看一眼。本文介绍将 EPUB、PDF 或 Kindle 电子书的高亮导入 Android 间隔重复卡组的 3 种途径：从繁琐的手动导出，到无需导出的原生内置复习阅读器。
Formats & Files
如何在 Android 上打开 AZW3 和 MOBI 文件（无需 Kindle 应用）
AZW3 或 MOBI 文件要么能在任何优秀的 Android 阅读器中打开，要么只能在 Kindle 中打开——差异仅在于文件头中的一个标志。本文介绍如何在十秒内辨别文件类型、哪些阅读器可以打开无锁文件，以及如何处理加密文件。
Formats & Files
如何检查 EPUB 是否包含 DRM 保护（3 种检测方法与 1 个常见误区）
EPUB 本质上是一个 zip 压缩包。它是否被加密锁定取决于内部的两个小文件——而其中一个常常让绝大多数检测工具产生误判。本文教您如何自行查看这些文件，或使用无需上传电子书的浏览器端工具进行安全检测。
Privacy & Control
锁匠的巧妙机关盒：解析 GemReader 安全 PIN 码输入
探索 GemReader 如何利用直接触控键盘、屏幕截图屏蔽以及 AES-GCM 加密，为您私密的锁定书库构建一道坚不可摧的精神防线。
Features & Study
学者的卡片箱：将您的阅读高亮转化为长期记忆
高亮标注不应在数字墓地里沉睡。探索 GemReader 的 Anki 导出功能如何将您的阅读笔记直接转化为间隔重复记忆闪卡。
Privacy & Control
旅行箱：用安全、无限的存储扩展您的书架
随着您的书库不断增加艰深教材和音频丰富的章节，手机内置存储可能会迅速填满。了解 GemReader 的安全外部存储迁移功能，如何让您将整个加密书库安全地迁移到 micro-SD 卡中。
Features & Study
GemReader 音频选项完全指南：从自定义有声书到本地神经 AI
将您的阅读圣殿转变为个性化的专属听书间。探索 GemReader 统一的音频中心如何让您完全掌控书籍的听觉体验——且绝不在速度、隐私或存储效率上妥协。
Architecture & Performance
技术揭秘：双引擎 TTS — 原生语音与本地神经 AI 的较量
无论您是视觉学习者、听觉处理者，还是两者的结合者，您的阅读应用都应适应您。探索 GemReader 完全离线的双引擎 TTS 架构如何同时提供轻量级系统语音和超逼真的神经 AI。
Features & Study
视听融合：实时同步高亮与免提阅读
体验终极的混合学习环境。探索 GemReader 如何将音频播放与活动文本高亮同步，完美融合视觉与听觉焦点。
Features & Study
将您的 EPUB 变有声书：为每个章节附加出版商音轨与自定义音频
虽然 AI 语音合成非常适合日常阅读，但人类的朗读依然无可替代。了解 GemReader 如何让您将自定义的预录音频文件直接附加到各个独立章节。
Privacy & Control
拨动密码盘：为什么 GemReader 的 PIN 码是一座金库，而不仅是密码
PIN 码不应仅仅是礼貌地要求手机隐藏文件夹，它应该是坚不可摧的金库上的物理密码盘。了解 GemReader 如何绕过漏洞百出的操作系统，为您提供真正的机械级安全。
Features & Study
无痕深度研习：基于内存的跨书阅读历史
当深度研究需要在不同文本间反复跳转时，您需要一根指引您回头的线——但绝不是一条留下永久痕迹的线。探索 GemReader 基于内存的会话级阅读历史功能。
Design Philosophy
个性化您的书库：全新色彩选项与自适应封面
无论您的数字书库有十本书还是一万本书，管理它们都应具有个性化、易读且视觉精美的体验。探索 GemReader 全新的书库色彩面板系统及动态深色模式自适应功能。
Features & Study
数字札记：将至爱篇章化为精美金句卡片
分享深刻的书籍段落不应以牺牲其美感和语境为代价。了解 GemReader 的金句卡片生成器如何通过轻触，将选中的文本瞬间转化为优雅、风格独特的视觉卡片。
Design Philosophy
自适应 UI 工程与上下文感知安全：设计智能工作区
阅读界面应当直观地适应您的设备并尊重您的隐私。了解 GemReader 的排版引擎如何动态缩放其工具，并在“锁定收藏夹”内阅读时自动禁止数据提取。
Features & Study
从文本选择到闪卡与即时查词：保持您的专注力
当您遇到生词或需要记忆的概念时，切换应用会打断您的注意力。了解 GemReader 如何将 SRS 闪卡和离线词典直接无缝融入您的阅读流中。
Features & Study
智能高亮与色彩编码笔记：绘制您的思维导图
支持六种独特色彩高亮，挂载富文本 Markdown 笔记，并在“宝石”书库中瞬间回顾您的深刻洞见。探索 GemReader 如何将动能学习注入被动阅读之中。
Features & Study
置顶书架：让您的至爱藏书触手可及
在庞大的数字书库中翻找，不应当像大海捞针。探索 GemReader 全新的“收藏”功能，如何让您瞬间聚焦那些最珍视的图书与研习指南。
Features & Study
读者的透镜：发掘藏在书卷中的微观世界
电子书里的图片不应当成为模糊不清、无法放大的视觉瓶颈。探索 GemReader 全新的交互式图片查看器，如何通过流畅的轻触放大与版面拖拽，让隐藏的细节清晰呈现。
Design Philosophy
数字书卷：致敬古典传统与契合现代律动的融合
从远古的泥板到现代的触控屏，文学的物理形态始终随着人类的智慧而演变。了解 GemReader 为何选择将垂直滚动作为移动阅读的自然节奏，以及我们如何探索将传统的“翻页感”引入数字时代。
Universal Accessibility
读懂路标：用你的母语畅游你的书库
软件不应让人感到陌生。探索 GemReader 如何通过原生系统菜单消除语言障碍，让全球读者都能轻松管理自己的书库。
Design Philosophy
无形之框：为什么最好的排版往往令人润物无声
字体应当是通往书籍思想的桥梁，而不应成为阅读门槛的阻碍。探索 GemReader 独特的语言包容性自动化排版设计，以及为什么我们选择用人文关怀与极简主义取代繁琐的技术配置菜单。
Privacy & Control
掌门之锁：为什么您的书架也需要应用锁功能
有时，对您阅读隐私的最大威胁并非来自复杂的网络安全漏洞，而仅仅是把手机借给身边的人。了解 GemReader 如何利用 Android 原生安全 API，为您的精神避风港加设一道温和而私密的防护锁扣。
Privacy & Control
穿梭人群：在公共场所防范窥屏面视
无论身处多么拥挤的空间，您的阅读书单都属于个人隐私。探索 GemReader 全新的自定义封面遮蔽与文本重命名功能，如何让您的书库远离窥探者的目光。
Features & Study
共享书库：让知识流淌在书页边际之外
GemReader 旨在为您的图书提供坚如磐石的私密庇护所， but 安全并不意味着孤立。了解我们完全开放、零 DRM 的架构如何让您轻松分享喜爱的 EPUB 书籍，将阅读的快乐传递给挚友。
Design Philosophy
塑造您的思维圣殿：GemReader 主题色彩如何契合阅读律动
无论身处何地，书中的文字始终如一，但周围的环境却会悄然改变您的阅读心境。了解 GemReader 精心设计的主题色系如何将冰冷的玻璃屏幕转化为专属的思维圣殿，每种调色盘均完美支持明亮与深色模式。
Privacy & Control
守护您的秘密花园：GemReader 如何保护您最私密的书籍
在一个要求分享一切的世界里，有些书只为您的眼睛而存在。探索 GemReader PIN 锁保险库的绝对隐私保护。
Design Philosophy
绘制您的旅程：GemReader 如何将翻阅实体书的进度感带入数字屏幕
在平整的玻璃屏幕上，900页的史诗看起来与10页的短文毫无区别。了解 GemReader 如何优雅地恢复数字阅读中失去的直觉进度感。
Features & Study
挖掘您的阅读「宝石」：GemReader 如何重塑书籍笔记
传统电子书阅读器将您的见解埋藏起来。了解 GemReader 如何将您的批注呈现出来，并让交互式练习册真正发挥作用——您可以直接在书里填写答案。
Privacy & Control
欢迎来到您的专属私人书库：导入您的 ePub 文件
掌握数字书架的主权，始于对数据的真正拥有。了解 GemReader如何让您在完全离线的状态下导入 ePub 文件，且无需任何服务器同步。
Privacy & Control
书库井然有序：全新推出嵌套收藏夹功能
轻松管理您的数字空间，支持多达三层的文件夹结构以及自动继承的加密安全设置。
Product Updates
翻页的独特律动：全新推出“分页”阅读模式
我们曾以为现代的垂直滚动就是数字书库所需要的一切。然而，我们错了。根据您的反馈，我们正式推出了全新的分页切换功能。
Feature Updates
标定阅读里程碑：全新 GemReader 进度条上线
探索我们全新、优雅的进度指示器如何利用您每天都在使用的概念，将纸质阅读直观、充实的推力融入到您的数字书架中。