What is SHA-256? Hashing explained

SHA-256 is a cryptographic hash function that maps any input to a fixed 256-bit digest - usually shown as 64 hexadecimal characters. The same input always produces the same hash; tiny input changes produce a completely different digest.

One-way fingerprints

Hashing is not encryption. You cannot reverse a SHA-256 digest to recover the original text. That makes it useful for integrity checks, content addressing, and detecting accidental changes - not for hiding data you later need to read back.

Where developers use SHA-256

• Checksums and download integrity verification
• Cache keys and content-addressed storage
• Building blocks inside larger protocols (with care)
• Fingerprinting non-secret config or payloads during debugging

Passwords are a special case

Do not store user passwords with plain SHA-256 alone. Prefer a dedicated password hashing scheme (argon2, bcrypt, scrypt) with salt on the server. SHA-256 alone is too fast for password storage against modern attacks.

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Next reads: How to generate a SHA-256 hash · SHA-256 vs MD5