# Hash Generator

What is SHA-256?

SHA-256 (Secure Hash Algorithm 256-bit) is a cryptographic hash function that produces a fixed 64-character hexadecimal string from any input. It is used for verifying file integrity, storing passwords, and API request signing.

What is the difference between SHA-1, SHA-256, and SHA-512?

SHA-1 (160-bit) is now considered weak and vulnerable to collision attacks. SHA-256 (256-bit) is the current standard for most security applications. SHA-512 (512-bit) offers greater security for high-value data but produces longer hashes.

How do I verify a file's integrity using a hash?

Download the file and run it through a hash generator. Compare the output with the official hash published by the file's source. If they match, the file is unmodified. If not, the file may be corrupted or tampered with.

Can two different inputs produce the same hash (hash collision)?

For SHA-256 and SHA-512, finding a collision is computationally infeasible with current technology. SHA-1 has known theoretical weaknesses, which is why SHA-256+ is recommended for security-critical applications.

Is my data safe — is anything uploaded to calculate the hash?

No. All hash computation runs locally in your browser using the built-in Web Crypto API (SubtleCrypto). No text or file is ever sent to any server.

Can I reverse a hash back to the original text?

No. Hash functions are one-way — given a hash output, it is computationally infeasible to recover the original input. This is what makes them useful for password storage and integrity verification.