Hash Generator
Generate SHA-1, SHA-256 and SHA-512 cryptographic hashes from any text.
Cryptographic Hashing: Verifying Integrity and Storing Passwords
Cryptographic hash functions like SHA-256 convert any input (text, file, password) into a fixed-size fingerprint. The same input always produces the same hash; changing even one character produces a completely different hash. Hashes are one-way — you cannot reverse-engineer the input from the hash. This property makes them essential for: verifying file integrity (checksums), storing passwords securely, digital signatures and blockchain transactions.
Frequently Asked Questions
What is SHA-256 and what is it used for? ▼
SHA-256 (Secure Hash Algorithm 256-bit) produces a 64-character hex string for any input. Uses: (1) File integrity verification — compare downloaded file hash against publisher's hash, (2) Password storage — store hash(password+salt) in database, never plain text, (3) SSL/TLS certificates, (4) Git commit hashes, (5) Bitcoin proof-of-work. SHA-256 is collision-resistant and currently considered secure.
What is the difference between MD5, SHA-1 and SHA-256? ▼
MD5 (128-bit, 32 hex chars): fast but broken — do not use for security. SHA-1 (160-bit, 40 hex chars): deprecated for SSL, vulnerable to collision attacks since 2017. SHA-256 (256-bit, 64 hex chars): current standard — recommended for all security applications. SHA-512 (512-bit, 128 hex chars): stronger, used when extra security margin is needed.
How to verify a file hash (checksum) after download? ▼
Download the file and find the hash (MD5/SHA-256) provided by the publisher. Copy the file hash from their website, paste it into the "Verify" field in our File Hash Generator tool, upload the file — green means the file is intact; red means it was corrupted or tampered with during download.
How are passwords hashed securely? ▼
Secure password hashing uses slow algorithms specifically designed for passwords: bcrypt, scrypt or Argon2 (not SHA-256, which is too fast). The process: hash(password + random_salt) and store both hash and salt. Never store plain text passwords. Never use MD5 or unsalted SHA for passwords.
Can a hash be reversed (cracked)? ▼
Cryptographic hashes are one-way by design — there is no reverse algorithm. However, attackers use rainbow tables (precomputed hash databases) and brute force to crack weak passwords. A hash of "password123" can be found in milliseconds. Strong, unique passwords with salting prevent rainbow table attacks.