Question 1

What is SHA-256?

Accepted Answer

SHA-256 (Secure Hash Algorithm 256-bit) is a cryptographic hash function that converts any input into a fixed 64-character hexadecimal string. It is part of the SHA-2 family and is widely used in security and blockchain.

Question 2

Is hashing reversible?

Accepted Answer

No. SHA-256 is a one-way function by design. It is computationally infeasible to recover the original input from a hash — this is what makes it useful for password storage and data integrity.

Question 3

What is SHA-256 used for?

Accepted Answer

Common uses include password verification (hashed storage), file integrity checking, digital signatures, blockchain transaction IDs, API request signing, and data deduplication.

Question 4

Is my input sent to a server?

Accepted Answer

No. All hashing is performed entirely in your browser using the Web Crypto API (SubtleCrypto.digest). Your input never leaves your device.

Question 5

What is the difference between SHA-256 and MD5?

Accepted Answer

SHA-256 is significantly more secure. MD5 is considered cryptographically broken and is vulnerable to collision attacks. Never use MD5 for security purposes — use SHA-256 or higher.