DiffCheck

ファイルハッシュ計算ツール

MD5、SHA-1、SHA-256、SHA-512のチェックサムを計算します。ファイルをドロップするだけでブラウザ内で即座に計算。

ファイルをドロップ、またはクリックして選択

あらゆるファイル形式に対応 — ブラウザ内で処理、サーバー送信なし

What Is a File Hash Generator?

A file hash generator computes a fixed-length checksum (hash) from the binary content of any file. This tool supports four algorithms: MD5, SHA-1, SHA-256, and SHA-512. Hashes are deterministic — the same file always produces the same hash — making them ideal for verifying that a downloaded file is identical to the original. All computation runs locally in your browser; no data is ever sent to a server.

How to Use the File Hash Generator

  1. Drag and drop a file onto the drop zone, or click the zone to open a file picker.
  2. All four hashes (MD5, SHA-1, SHA-256, SHA-512) are computed automatically.
  3. Click the Copy button next to any hash to copy it to the clipboard.
  4. Compare the hash against the checksum published by the file's source to verify integrity.

Features

  • Computes MD5, SHA-1, SHA-256, and SHA-512 simultaneously
  • Drag-and-drop or click-to-browse file selection
  • Displays file name, size, and MIME type
  • One-click copy for each hash value
  • 100% client-side — files never leave your browser
  • No file size limit (subject to available browser memory)

FAQ

Is my file uploaded to a server?

No. All hashing is done entirely in your browser using the FileReader API and the Web Crypto API. Your file never leaves your device.

What is a file hash used for?

File hashes (checksums) are used to verify file integrity. After downloading a file, you can compare its hash against the official checksum published by the source to confirm the file has not been corrupted or tampered with.

Which hash algorithm should I use?

SHA-256 is the recommended choice for most integrity verification tasks. MD5 and SHA-1 are faster but cryptographically broken — they are still useful for non-security checksums (e.g., detecting accidental corruption) but should not be used where collision resistance matters.

What is the maximum file size?

There is no hard limit — files are processed in memory via the browser FileReader API. In practice, files up to several gigabytes work fine in modern browsers, though very large files may be slow on lower-end hardware.