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Convert ZIP to 7Z: Free Online Converter

Convert ZIP Archive to 7-Zip Archive online for free. Fast, secure archive conversion with no watermarks or registration.

163,297件のファイルを変換済み

ZIP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。

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

変換成功率をリアルタイムで見る

ZIP から 7Z への設定

エンジン
アーカイブ
設定
設定は不要です。適切な初期値が使われます。

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、.zip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.7zファイルをダウンロードしてください。

ZIPから7Zへの変換について

ZIP is the most universally supported archive format, created by Phil Katz in 1989 and built into every modern operating system. ZIP uses DEFLATE compression and per-file storage, enabling random access to individual entries. 7Z uses LZMA and LZMA2 algorithms from the 7-Zip project that consistently deliver 20-40% better compression than ZIP's DEFLATE.

Converting ZIP to 7Z recompresses your universally compatible archive using the most efficient general-purpose compression available. This conversion targets storage optimization: when you need to minimize archive footprint for cloud storage, archival repositories, or bandwidth-constrained transfers and the recipient has 7-Zip or p7zip available for extraction.

ZIPを7Zに変換する理由

7Z's LZMA2 compression produces meaningfully smaller archives than ZIP's DEFLATE across virtually all data types. For a 100 MB ZIP of source code, the 7Z equivalent might be 60-70 MB — a 30-40% reduction. For organizations storing thousands of ZIP archives on cloud platforms where every gigabyte has a monthly cost, the savings compound into significant budget impact.

7Z's solid archive mode adds another compression advantage. ZIP compresses each file independently, unable to exploit redundancy between files. 7Z's solid mode treats multiple files as a single data block, dramatically improving compression when files share content — common in source code, documentation sets, and configuration bundles. A ZIP containing 100 similar configuration files may compress 50-60% better as a solid 7Z.

主な活用例

  • Reducing cloud storage costs by recompressing ZIP archive collections with LZMA2
  • Creating space-optimized backups from ZIP-distributed software and data packages
  • Minimizing archive transfer time over bandwidth-constrained connections
  • Consolidating many small ZIP archives into solid 7Z archives for maximum compression
  • Adding AES-256 encryption to ZIP archives that use the weak ZipCrypto encryption method

仕組み

The ZIP archive is read by parsing the central directory (located at the end of the file) to enumerate all entries. Each file is decompressed from its individual DEFLATE stream, CRC32-verified, and placed in a temporary directory. The extracted file tree is then packed into a 7Z archive using LZMA2 compression with solid mode enabled by default. LZMA2 uses dictionary sizes up to 64 MB, Markov chain modeling, and range coding to achieve compression ratios that DEFLATE cannot approach.

品質とパフォーマンス

Entirely lossless. Every file from the ZIP is extracted (CRC32-verified) and repacked into 7Z with identical byte content. No data is altered. The 7Z output will be 20-40% smaller than the ZIP while containing bit-for-bit identical files. The improvement comes entirely from the more efficient compression algorithm.

Document EngineModerateMinimal Quality Loss

デバイス互換性

DeviceZIP7Z
Windows PCPartialPartial
macOSPartialPartial
iPhone/iPadPartialPartial
AndroidPartialPartial
LinuxPartialPartial
Web BrowserNoNo

最良の結果を得るためのヒント

  • 1Disable solid mode if you frequently need to extract individual files — solid archives require processing entire blocks for single-file extraction
  • 2For maximum compression, enable solid mode and set a large dictionary size — this is optimal for archival where extraction speed is secondary
  • 3Consider maintaining both ZIP (for distribution) and 7Z (for archival) copies of important archives
  • 4If security is a concern, converting from ZipCrypto-encrypted ZIP to AES-256-encrypted 7Z is a meaningful upgrade
  • 5Verify the 7Z output with `7z t archive.7z` before deleting original ZIP files

関連する変換

ZIP to TAR ConverterZIP to TGZ ConverterTGZ to 7Z ConverterCompress PDFMerge PDFSplit PDF

ZIP to 7Z conversion trades universal compatibility for 20-40% better compression and optional AES-256 encryption. Ideal for archival storage, large collections, and environments where 7-Zip is available.

ZIPと7Zの比較

特徴ZIP7Z
正式名称ZIP Archive7-Zip Archive
拡張子.zip.7z

よくある質問

Typically 20-40% smaller for text content and structured data. Already-compressed files (JPEG, MP4) show minimal improvement. Solid archives with many similar files show the largest gains.
Yes. ZIP's legacy ZipCrypto is cryptographically broken. 7Z uses AES-256 (CBC mode) which is considered secure. If your ZIP was using ZipCrypto, converting to encrypted 7Z is a significant security upgrade.
Yes, but it requires processing the entire solid block containing that file. ZIP allows true random access to any file. If individual file access is important, disable solid mode during conversion.
No. macOS Finder, iOS, and Android do not natively extract 7Z. Windows File Explorer also does not support 7Z. You need 7-Zip, The Unarchiver, or equivalent tools. This is the main trade-off versus ZIP.
Yes. The complete directory hierarchy, filenames, and relative paths from the ZIP are maintained in the 7Z output.

関連する変換とツール

ZIPから他の形式への変換

ZIP to TAR→ZIP to TGZ→

他の形式から7Zへの変換

TGZ to 7Z→

関連ツール

PDF Compressor→Merge PDF→Split PDF→

さらに見る

All Archive Conversions→

ZIPを他の形式に変換

ZIP to TARZIP to TGZ

他の形式を7Zに変換

TGZ to 7Z