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String Hash Calculator

Calculate MD5, SHA series hash values for strings, supports multiple hash algorithms

Hash Settings
Example Data
Hash Calculation Results

Select hash algorithms and enter text to start calculation

Hash Algorithm Knowledge

What is Hash Algorithm?

Hash algorithms map data of any length to fixed-length hash values. Good hash algorithms have characteristics like determinism, fast computation, irreversibility, and collision resistance. Hash values are commonly used for data integrity verification and password storage.

Algorithm Security

MD5 and SHA-1 have been proven to have collision vulnerabilities and are not recommended for security scenarios. The SHA-2 series (SHA-224/256/384/512) are currently recommended secure hash algorithms, with SHA-256 being the most commonly used.

Application Scenarios

Hash algorithms are widely used in password storage, digital signatures, file verification, blockchain, data deduplication and other fields. Different scenarios have different requirements for security and performance, requiring appropriate algorithm selection.

Salt Values

In password storage, salt values should be used to enhance security. Salt is random data that is combined with passwords before hashing, effectively preventing rainbow table attacks and the problem of identical passwords producing identical hashes.

Hashing model
A hash function maps input bytes to a fixed-length digest. Good cryptographic hashes are designed to be one-way and collision-resistant.
digest = HashAlgorithm(input bytes)
same input + same algorithm = same digest
small input change -> very different digest
digest length depends on algorithm, not input length
input bytes
Encoded source data
Text is converted to bytes before hashing; file hashes depend on exact file bytes.
digest
Hash output
A fixed-length hexadecimal string such as SHA-256 output.
algorithm
MD5, SHA-1, SHA-256, SHA-512
Different algorithms produce different digest lengths and security properties.
How this hash calculator works
The calculator generates deterministic digests for text or file content so users can compare checksums and inspect algorithm output.
  1. Read the text input or uploaded file content locally in the browser.
  2. Encode text as bytes before hashing.
  3. Calculate selected digest algorithms and display hexadecimal output.
  4. Allow copying or downloading output for checksum comparison workflows.
  5. Keep the input local to the browser; the component does not upload the value to a server.

Important notes

  • MD5 and SHA-1 are not appropriate for collision-resistant security decisions.
  • Plain hashes are not password storage. Passwords need a slow password-hashing algorithm with salts.
  • A matching checksum confirms the same bytes were seen by the hash function; it does not prove the file is safe.
Hash examples
Use these examples to understand what a digest can and cannot prove.

Release checksum

A project publishes a SHA-256 checksum for a downloadable file.

  • Download the file
  • Calculate SHA-256
  • Compare with the published digest

Matching digests mean the downloaded bytes match the published bytes.

Checksum comparison is useful for integrity, but trust still depends on the source of the published checksum.

Text fingerprint

Two systems should be producing identical normalized strings.

  • Input: user@example.com
  • Algorithm: SHA-256

The same normalized input always gives the same digest.

Whitespace, Unicode normalization, and casing changes produce different hashes.

Weak algorithm warning

A legacy integration still asks for MD5.

  • Input file
  • Algorithm: MD5

A deterministic MD5 digest is produced.

Use MD5 only for legacy compatibility or non-security checks, not for collision-resistant trust.

Hash FAQ
Common questions about checksum comparison, password storage, and algorithm choice.