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Convert MOBI to EPUB: Kindle to Universal Ebook

Convert Kindle MOBI ebooks to universal EPUB format. Read on Apple Books, Kobo, Nook, and any EPUB reader. Free online converter.

163,297件のファイルを変換済み

MOBIに対応

アップロードすることで、これらのファイルの権利を有していること、および利用規約に同意することを確認したものとみなされます。

変換設定: ファイルを追加すると調整できます

Tune typography and image handling for a specific device

Applied to all 4 sides

Set to 0 to preserve the source font size

Bundle every font referenced by the stylesheet (larger file)

Convert plain quotes/dashes/ellipses to typographic equivalents

Keep source font sizes verbatim (skip automatic font rescaling)

安全な転送

HTTPS暗号化アップロード

プライバシー優先

ゲストのファイルは約2時間で自動削除

登録不要

すぐに変換を開始

どこでも動作

あらゆるブラウザ、あらゆるデバイス

MOBI から EPUB への設定

エンジン
電子書籍
設定
調整できる設定: 6
  • Output Profile
  • Margin (px)
  • Base Font Size (pt)
  • Embed All Fonts
  • Smarten Punctuation
  • Disable Font Rescaling

変換方法

1

アップロードエリアにドラッグするか、クリックして選択し、.mobiファイルをアップロードしてください。

2

必要に応じて出力設定を調整してください。デフォルト設定ではオリジナルの品質を維持します。

3

「変換」をクリックし、準備ができたら.epubファイルをダウンロードしてください。

MOBIからEPUBへの変換について

MOBI is Amazon's legacy ebook format, designed exclusively for Kindle devices and apps. While Amazon has moved to KFX and AZW3 for newer content, millions of MOBI files still exist in personal libraries, self-published archives, and ebook collections accumulated over the past decade. The problem: MOBI files only work on Kindle devices and the Kindle app. They cannot be opened by Apple Books, Kobo, Nook, Google Play Books, or any standard EPUB reader. Converting MOBI to EPUB unlocks your ebook library for universal reading.

Our MOBI to EPUB converter uses a dedicated eBook engine to parse the MOBI file structure and rebuild it as a standards-compliant EPUB 3.0 file. The conversion preserves text content, chapter structure, table of contents, embedded images, and basic formatting. The resulting EPUB works on every major reading platform and e-reader device outside the Amazon ecosystem.

MOBIをEPUBに変換する理由

Device freedom is the core benefit. EPUB is the universal ebook standard supported by Apple Books, Kobo, Nook, Google Play Books, Calibre, and dozens of other reading applications. Converting MOBI to EPUB means you are no longer locked into the Kindle ecosystem — read your books on any device you choose, whether that is an iPad, a Kobo Clara, or a Linux desktop.

Reading feature improvements come automatically. EPUB 3.0 supports enhanced typography, embedded fonts, MathML equations, SVG graphics, audio/video elements, and semantic structure that MOBI's aging format cannot represent. E-reader apps provide richer rendering for EPUB content compared to MOBI, including better hyphenation, typographic ligatures, and responsive layout on varied screen sizes.

Library management simplifies dramatically. EPUB is an open standard with consistent behavior across platforms. Managing a library of EPUB files in Calibre, organizing them on cloud storage, or sharing with family members is straightforward. MOBI's proprietary structure and DRM restrictions complicate library management and limit your options. Converting to EPUB gives you an open-format copy of your books that you fully control.

主な活用例

  • Convert a Kindle MOBI library to EPUB for reading on Apple Books, Kobo, or Nook devices
  • Transform self-published MOBI ebooks to EPUB for distribution on non-Amazon platforms
  • Convert MOBI textbooks and reference books to EPUB for reading on iPad and Android tablets
  • Create EPUB backups of MOBI ebook purchases for format-agnostic archival storage
  • Convert MOBI fiction collections to EPUB for sharing with reading groups who use varied devices
  • Transform MOBI technical documentation to EPUB for integration into corporate reading systems

仕組み

Calibre's MOBI input plugin parses the Mobipocket container, extracting the HTML content stream, embedded images, metadata records (title, author, publisher, ISBN, cover), and the table of contents structure. MOBI files use a variant of HTML for content markup, which Calibre normalizes to well-formed XHTML for the EPUB output.

The EPUB output conforms to EPUB 3.0 specifications with proper spine ordering, navigation document (nav.xhtml), legacy NCX table of contents for backward compatibility, and OPF manifest listing all resources. CSS styling is cleaned and optimized — MOBI's often verbose inline styles are consolidated into external stylesheets for cleaner structure.

Cover image extraction is handled specially. MOBI files store the cover image in a dedicated metadata record; the converter extracts it and sets it as the EPUB's cover element with proper metadata tagging so e-readers display it correctly in library views. Book metadata (title, author, series, description, language, publisher) is mapped from MOBI's EXTH records to EPUB's Dublin Core metadata fields.

品質とパフォーマンス

MOBI to EPUB conversion is effectively lossless for content. Both formats use HTML/XHTML for text representation, so the text, chapter structure, and images transfer without degradation. Minor formatting differences may occur where MOBI used proprietary rendering directives that have no EPUB equivalent, but these are typically cosmetic (margin widths, font sizes) rather than content-affecting. The EPUB output is generally cleaner and more standards-compliant than the MOBI source.

eBook EngineFastLossless

デバイス互換性

DeviceMOBIEPUB
WindowsNoPartial
macOSNoNative
iOSNoNative
AndroidPartialPartial
LinuxPartialPartial
ChromeOSNoPartial

MOBI to EPUB: real-world performance

SpeedAbout a second
Output size~18% smaller (measured 0.2 MB → 0.2 MB).
QualityReflowable text and chapters preserved.
EngineeBook engine, server-side.

Measured on our servers, June 2026, on a sample e-book. See all measured conversions →

最良の結果を得るためのヒント

  • 1Verify that your MOBI file is DRM-free before attempting conversion — DRM-protected files from Amazon cannot be processed
  • 2Check the cover image in the EPUB output — some MOBI files store covers at low resolution that may look pixelated on high-DPI readers
  • 3After conversion, validate the EPUB with an EPUB checker tool to ensure full compliance with the standard
  • 4For best results with heavily formatted MOBI files, review the EPUB in Calibre's editor and clean up any CSS inconsistencies
  • 5Convert AZW3 files rather than MOBI when both are available — AZW3 preserves more formatting in the EPUB output

関連する変換

MOBI to EPUB conversion liberates your Kindle ebook library for universal reading. Whether switching to a Kobo, reading on Apple Books, or simply wanting an open-format backup, our eBook converter produces clean, standards-compliant EPUB files that work everywhere.

MOBIとEPUBの比較

特徴MOBIEPUB
正式名称Mobipocket eBookElectronic Publication
拡張子.mobi.epub

よくある質問

No. DRM-protected ebooks cannot be converted — the encryption prevents access to the content. Only DRM-free MOBI files (from personal documents, self-published authors, or DRM-stripped purchases) can be converted. This applies to all conversion tools, not just ours.
Yes. The MOBI table of contents structure is converted to both an EPUB 3 navigation document and a legacy NCX file for maximum reader compatibility. Chapter headings and hierarchy are preserved.
Yes. All images embedded in the MOBI file — cover art, illustrations, diagrams, and inline graphics — are extracted and embedded in the EPUB at their original quality and positions within the text.
Modern Kindles support EPUB natively since firmware updates in late 2022. For older Kindles, you can send the EPUB via Amazon's Send-to-Kindle email service, which converts it automatically.
MOBI is Amazon's older format with limited HTML support. AZW3 (KF8/Kindle Format 8) is the newer format supporting enhanced typography, fonts, and CSS3. Both can be converted to EPUB. If you have AZW3 files, convert those for better formatting preservation.
Yes. Title, author, publisher, description, language, series information, and cover image are all transferred from the MOBI's EXTH metadata records to the EPUB's Dublin Core metadata fields. E-readers will display the correct information in their library views.
MOBI to EPUB conversion is fast — typically 5-15 seconds for a standard novel. Ebooks with many images (illustrated guides, comics, textbooks) take slightly longer due to image processing. File sizes are similar between formats.
The output is EPUB 3.0 with backward compatibility elements (NCX table of contents) for older EPUB 2 readers. This ensures the widest possible device and app compatibility.

関連する変換とツール

MOBIから他の形式への変換

他の形式からEPUBへの変換

関連ツール

MOBIを他の形式に変換

他の形式をEPUBに変換