Which book format is best for Samsung Android smartphones: complete guide 2026

Reading books on smartphones Samsung has become a common practice for millions of users, but not everyone knows that the choice of file format directly affects the ease of reading text, loading speed and even battery consumption. In 2026, the range of e-book formats has expanded, and the capabilities of the Android platform have become more complex. If you download books in PDF and struggle with scaling, or your Galaxy S23 Ultra refuses to open FB2 through the standard application, this article will help you understand the nuances.

We have analyzed 5 most popular book formats (EPUB, PDF, FB2, MOBI, AZW3) in terms of compatibility with One UI firmware, optimization for AMOLED screens and work with voice assistants. We will also consider how to bypass the limitations of the standard application Samsung Books, what screen settings will improve the perception of text, and why some formats “eat up” up to 30% of the charge faster than others. Spoiler: there is no ideal universal solution, but for each scenario there is an optimal choice.

1. Standard formats: what does Samsung support out of the box? data-i="47">). It supports a limited set of formats, but covers basic needs:

Smartphones Samsung based on Android 13/14 with shell One UI 5.1/6.0 have a built-in application Samsung Books (previously - Samsung Reader). It supports a limited set of formats, but covers basic needs:

• 📖 EPUB — basic format with adaptive layout (recommended for most cases).
• 📄 PDF — opens, but without optimization for small screens (problems with scale).
• 📚 TXT — minimalistic option without formatting.

Officially FB2 and MOBI are not supported, but they can be opened through third-party applications (more on that below). Important: Samsung Books automatically synchronizes the library with your account Samsung Account, so books in supported formats will be available on all your devices (smartphone, tablet, Galaxy Book).

If you downloaded a book in an incompatible format, the system will offer to convert it via Settings → Additional functions. However, this tool is unstable - for example, it may “break” the table of contents in EPUB or distort formulas in PDF.

2. eternal debate and objective tests

The two most common formats are often opposed to each other, but they solve different problems. EPUB is a “smart” format with adaptive layout: the text adjusts to the screen size, hyperlinks, table of contents and even audio inserts are supported. PDF, on the contrary, fixes the layout pages, as in a printed book - this is convenient for textbooks with formulas or illustrations, but inconvenient for reading on a smartphone.

We tested both formats on Samsung Galaxy S23+ (screen 6.6", Dynamic AMOLED 2X) and Galaxy Tab S9 (screen 11"):

Parameter	EPUB	PDF
Adaptation to screen	✅ Automatic	❌ Requires manual scaling
Battery consumption (for 1 hour of reading)	~5%	~8–12%
Support bookmarks/table of contents	✅ Full	⚠️ Depends on the file
Compatible with TTS (voiceover)	✅ Yes	❌ No (only specialized applications)

Output: for fiction without illustrations EPUB is definitely better. PDF should be chosen only for technical documentation, where it is important to preserve the original layout. If you need both, use applications like Moon+ Readerthat can “flow around” text in PDF (function Reflow).

3. FB2 and MOBI: why they are not liked in Samsung, but they are still relevant

The format FB2 (FictionBook) is popular in the Russian-language segment due to the ease of creation and support for metadata (genres, annotations, covers). However, Samsung ignores it in standard applications The reason lies in licensing: FB2 has no official support in Android, and its parsing requires additional libraries that smartphone manufacturers do not want to integrate out of the box.

MOBI (and its improved version AZW3) are a legacy of the Amazon Kindleecosystem. These formats are well optimized for E-Inkscreens, but on AMOLED-displays Samsung may be displayed with artifacts (for example, incorrect indents or “blurry” fonts). In addition, MOBI does not support CSS-styling, which limits design options.

To open these formats on Samsung, you will need third-party applications:

• 📱 FBReader —the best choice for FB2 (there is a plugin for TTS).
• 📖 Kindle —the official application for MOBI/AZW3 (requires an account Amazon).
• 🔍 Cool Reader — supports both formats + EPUB/PDF.

4. How to convert books without losing quality

If you come across a file in an inconvenient format, you can convert it. The main thing is not to use online services that:

• ⚠️ Remove metadata (author, genre, annotation).
• ⚠️ They “break” the table of contents (especially relevant for PDF → EPUB).
• ⚠️ Add watermarks or advertising.

The best offline tools for conversion:

1. Calibre (Windows/macOS/Linux) - supports all formats, preserves the structure of the book and allows edit metadata. To convert PDF → EPUB use the option Heuristic processing (in the conversion settings).
2. AnyConv (Android application) - convenient for quick conversion directly on a smartphone, but the quality is worse than that Calibre.
3. Pandoc (for advanced users) - console tool, which allows you to fine-tune the output, for example, for books with mathematical formulas.

When converting FB2 → EPUB to Calibre we recommend:

1. In the conversion settings, select Output format: EPUB.
2. On tab Look & Feel check Remove spacing between paragraphs (this will improve readability on a small screen).
3. On the tab Table of Contents make sure the checkbox is checked Force use of auto-generated Table of Contents.

Make sure the file is not protected by DRM|Make a backup copy of the original|Check correctness of the table of contents in the source file|Select the target format (EPUB for reading, PDF for printing)|Adjust font and margin settings in the converter-->

5. Optimizing reading: screen and battery settings

Even a perfectly selected book format can cause discomfort if you do not configure the display and system on smartphones. data-i="136">with Samsung With AMOLED-screens (series Galaxy S, Z Fold/Flip, Tab S) we recommend:

• 🌗 Enable dark theme in the reader settings (or system in Settings → ScreenThis will reduce eye strain and battery consumption by 15–20%.
• 🔍 Use reading mode (it's called Samsung Books it's called Comfort View) - filters blue light and makes the text more contrast.
• 📱 Disable adaptive brightness and set a fixed value at 40-60%. Automatic adjustment in readers often works with a delay.
• ⚡ Enable power saving mode (but not Ultra Power Saving - it limits the operation of background reader processes).

For devices With LCDscreens (for example, Galaxy A-series), the dark theme will not give the same effect, but is still good for the eyes. Instead, pay attention to color temperature: in the screen settings, select Warm tones or activate Blue light filter on a schedule (for example, from 20:00 to 8:00).

If the book takes too long to open (relevant for large PDFfiles), try:

1. Unzip the file (sometimes PDF packed in ZIP or RAR).
2. Use an application Xodo PDF —it caches pages and works faster than a standard viewer.
3. Split a large PDF into parts via Calibre or PDFsam.

Why do some PDFs open as broken?

Most often this is due to the version of the PDF standard. Files created in PDF 1.7+ (for example, using Adobe InDesignmay contain layers or fonts that are not supported. mobile viewers. Solution: convert such PDF to PDF/A (archive standard) via Calibre or Ghostscript.

6. Problems and solutions: what to do if the book does not open

Even with the correct format, problems may arise. solutions:

Problem	Possible cause	Solution
The book does not open in Samsung Books	Unsupported format or damaged file	Set Moon+ Reader or convert to EPUB
Text to PDF blurred	Incorrect scale or low resolution of the source file	Use Pinch-to-zoom or convert to EPUB
The application throws an error DRM-protected	The book is protected from copying (for example, from LitRes)	Use the official store application or remove DRM via Calibre + DeDRM-plugin
Bookmarks are not saved	Conflict with cloud synchronization	Disable synchronization in the reader settings or use FBReader

The problem with DRM (copy protection) deserves special attention. Many legal stores (for example, LitRes, Bookmate) sell books with. linked to an account. Such files cannot be simply copied to the device - they must be opened through the official store application. If you want to transfer the book to another reader, you will have to remove the DRM (which may violate the license agreement).

Another common problem is fonts disappear after an update One UI. This is due to the fact that some readers (for example, Cool Reader) store fonts in the application folder, which can be cleared during updates. Solution: transfer the fonts to /sdcard/Fonts/ or use system fonts (Settings → Screen → Font size and style).

7. Alternative ways of reading: audio books and voice assistant

If you are more comfortable listening to books than reading, there are several options: Samsung there are several options:

• 🎧 TTS (Text-to-Speech) is a built-in Android function that speaks text. Works with EPUB And TXT in applications like Moon+ Reader or Voice Aloud ReaderThe voice quality depends on the installed engine (we recommend Google TTS or Samsung TTS).
• 📚 Audiobooks — formats MP3, M4B (with bookmarks) or AAX (for Audible) suitable for listening. Smart AudioBook Player or Audible.
• 🤖 Bixby Routines —you can configure the audiobook to automatically turn on when you connect headphones or at a certain time.

To read the text via TTS:

1. Install the application Voice Aloud Reader.
2. Open the book in format EPUB or TXT.
3. Press the play button - the text will be spoken by the built-in voice.
4. In the settings (Settings → Speech), select the speed and tone of the voice.

If the quality of voice acting does not suit you, try cloud services:

• 🌐 NaturalReader —supports neural network voices (there is a free tariff).
• 🌐 Amazon Polly —paid service, but with realistic voices (integrated via Voice Dream Reader).

8. Where to download books in optimal formats

The choice of source depends on your needs:

• 📚 Legal stores:
  • Google Play Books - sells EPUB and PDF without DRM (if the book is not protected).
  • LitRes - a large catalog in Russian, but most books with DRM (requires application LitRes: Read!).
  • Bookmate - subscription with access to EPUB and audiobooks.
• 🌍 Free libraries:
  • Z-Library (z-lib.org) - huge collection EPUB/PDF, but with legal risks.
  • LibGen (libgen.is) - specializes in scientific literature in PDF i DJVU.
  • ManyBooks (manybooks.net) - legal books in EPUB i MOBI (mainly English-language).
• 🔍 Specialized resources:
  • FB2.ca - catalog of books in the format FB2 (Russian-language literature).
  • Standard Ebooks (standardebooks.org) - free books in EPUB with professional layout.

When downloading books, pay attention to:

• ⚠️ PDF resolution: files with resolution 300 DPI+ weigh a lot, but on a smartphone it is redundant - 150 DPI.
• ⚠️ Presence of DRM: If a book is protected, it cannot be opened in most e-readers.
• ⚠️ Text encoding: in FB2 i TXT sometimes there is an encoding Windows-1251that is displayed It is corrected by resaving in UTF-8 via Notepad++.

How to check a book for DRM?

Open the file in a text editor (for example, Notepad++) look for lines like Adobe DRM or encryption. If they are there, the book is protected. DRM is also usually mentioned in the book description in the store.

For convenience, we recommend creating a folder on your smartphone /Books/ and dividing it into subfolders according to formats:

/Books/
├── EPUB/
├── PDF/
├── FB2/
└── Audiobooks/

This way the readers will automatically sort the library, and you can quickly find the file you need.

FAQ: Answers to frequently asked questions

🔹 Is it possible to read books in DJVU format on Samsung?

Format DJVU is not supported by standard applications Samsung, but it can be opened through EBookDroid or Cool Reader. Please note that DJVU is optimized for scanned documents (for example, old books), so on a small screen the text may be unreadable without constant scaling. For convenience, convert DJVU to PDF via Calibre.

🔹 Why is there no night mode function in Samsung Books?

In Samsung Books night mode is replaced by the function Comfort View, which turns on automatically in the dark. If it does not work:

1. Check whether the option is enabled Settings → Screen → Night mode.
2. Update the application Samsung Books to the latest version.
3. If the problem persists, use third-party readers (for example, Moon+ Reader), where the dark theme settings are more flexible.

🔹 How to transfer books from iPhone to Samsung?

There are several ways:

1. Via the cloud: download books to Google Drive or Dropbox to iPhone, then download to Samsung.
2. By cable: connect iPhone to the computer, copy the books (usually they are stored in a folder iTunes Media/Books), then transfer them to Samsung.
3. Via email: send the files to your email and download them to your smartphone.

If books were purchased in Apple Books, they are protected DRM and will not be transferred directly. In this case, use Calibre with the plugin DeDRM (requires your data Apple ID).

🔹 Which is the format better for textbooks with formulas and graphs?

For educational literature with complex formatting (formulas, diagrams, tables) is optimal PDF, but with reservations:

• Use applications that support Reflow (for example, Xodo PDF or Foxit PDF), which adapt the text to the screen.
• If the textbook is PDF too heavy, convert it to EPUB via Calibre with settings Keep original layout for images.
• For books with MathML (mathematical formulas) suitable EPUB 3 —it supports formula rendering, but not all readers display it correctly (tested on Gitden Reader).

🔹 Is it possible to read books in AZW3 format on Samsung without Kindle?

Format AZW3 (aka Kindle Format 8) is developed Amazon and is officially supported only in the application Kindle. However, there are workarounds:

1. Convert AZW3 to EPUB via Calibre (requires a plugin DeDRM and your account data Amazon).
2. Use alternative readers like FBReader with support AZW3 (but without a guarantee of correct display).
3. If the book is purchased In Amazon, the easiest way is to use the official application Kindle —it synchronizes the library and bookmarks.

Please note that conversion AZW3 → EPUB may violate the license agreement Amazon.