MD5 / SHA Hash Calculator — Text and File Hashing

工具介绍

A hash function maps data of any length to a fixed-size fingerprint. Hashes are used for file integrity checks, password storage (with salt), digital signatures, deduplication, and content addressing. This tool supports MD5, SHA-1, SHA-256, and SHA-512. All computation runs locally in your browser — nothing is uploaded.

怎么使用

1. Choose algorithm: MD5 / SHA-1 / SHA-256 / SHA-512
2. Enter text or drag in a file
3. The hash appears below; click to copy

常见用例

• Verify a downloaded file matches the official checksum
• Understand Git's commit hash model
• Hashing passwords (but use bcrypt/argon2, not raw MD5)
• Quick content fingerprinting for deduplication

常见问题

Q: Is MD5 insecure?
A: For passwords yes (rainbow tables). For file integrity, cache keys, and fingerprints it is still fine. For security use SHA-256+.

Q: SHA-1 vs SHA-256?
A: Performance is similar. Default to SHA-256 (or SHA-3) for security.

Q: File vs text hash?
A: Same algorithm; large input. SHA-256 produces 64 hex chars.

小贴士

For multi-GB files use sha256sum on the command line — browser hashing is fine but slower.

Never store MD5/SHA of passwords. Use bcrypt/argon2 with a salt.

Same hash = byte-identical content. Great for verifying uploads.