File Checksum Calculator は何をしますか？
File Checksum Calculator はブラウザ上でデータを調査するツールで、結果と制限を明確に示します。 検証済みの機能： Local file hashing, Expected-value verification, Four algorithms, 200 MB guardrail.
A matching checksum proves equality, not trust
A match shows that the file bytes equal the bytes used to publish the checksum. It does not prove who published either value; use a signed release, authenticated channel, or package signature when origin matters.
使い方
- Choose SHA-256, SHA-512, SHA-1, or MD5, then select one local file no larger than 200 MB.
- Optionally paste the publisher’s expected checksum; spaces and letter case are ignored during comparison.
- Confirm Match or Mismatch and copy the calculated checksum with its algorithm name.
実際の入出力例
Verify a three-byte text file
入力
File bytes: 61 62 63 (UTF-8 text "abc")
Algorithm: SHA-256出力
ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015adThis known SHA-256 value verifies that the selected file contains exactly the three bytes for abc.
一般的なエラーと対処
| 症状 | 原因 | 対処 |
|---|---|---|
| The calculated value does not match the published checksum. | The download is different, damaged, transformed, or compared with the wrong algorithm. | Confirm the algorithm and source, download the file again, and do not use it until the mismatch is explained. |
| The file is rejected before hashing. | The selected file exceeds the page’s 200 MB browser-memory guardrail. | Use a streaming desktop checksum utility for larger files. |
Important behavior of File Checksum
このツール固有の制限： A matching checksum proves byte equality, not that the publisher or file is trustworthy.
標準と実装の参考資料
- W3C Web Cryptography API (opens in a new tab)Defines the browser digest API used for SHA calculations.
- NIST FIPS 180-4 — Secure Hash Standard (opens in a new tab)Specifies the SHA algorithms exposed by this tool.
File Checksum — FAQ
Does the File Checksum upload my input?
No. Processing runs in the current browser tab, and the page does not send tool input to a KitLumi processing endpoint.
What input does the File Checksum accept?
It accepts one local file up to 200 MB and an optional expected checksum. The workspace checks the input and reports malformed or unsupported values before it produces a result.
What does the File Checksum produce?
It produces an MD5, SHA-1, SHA-256, or SHA-512 hexadecimal digest. Copy and download controls appear when the output format supports them.
What limitation should I know?
A matching checksum proves byte equality, not that the publisher or file is trustworthy.
更新内容
実質的な更新： File Checksum: Added Local file hashing, Expected-value verification, Four algorithms, 200 MB guardrail, responsive controls, explicit runtime disclosure, and task-specific examples and limitations.