Adler-32 Checksum

Computes the Adler-32 checksum of text.

This Adler-32 checksum tool computes the Adler-32 hash of any text you enter, returning the result in both hexadecimal and decimal form. Adler-32 is a fast checksum algorithm (used in zlib and the PNG format) that detects accidental data corruption, and it's handy when you need a quick integrity check or want to verify a value against another implementation.

Common uses

  • Verify an Adler-32 checksum reported by zlib, PNG tooling, or another library
  • Generate a lightweight integrity value for a short string or config snippet
  • Compare two text inputs by checking whether their checksums differ
  • Learn or demonstrate how the Adler-32 algorithm works on real input
  • Produce a fast non-cryptographic fingerprint for caching or change detection

FAQ

Is my data sent to a server?

No. The checksum is computed entirely in your browser using JavaScript, and nothing you type is uploaded or stored anywhere.

What output format does the tool produce?

It outputs the Adler-32 value twice: as an 8-digit zero-padded hexadecimal string and as an unsigned decimal number.

How does it handle non-ASCII characters?

The input text is encoded as UTF-8 bytes before the checksum is calculated, so multi-byte characters are hashed by their UTF-8 byte sequence.

Is Adler-32 suitable for security or cryptography?

No. Adler-32 is a non-cryptographic checksum meant to catch accidental errors, not to resist deliberate tampering. Use a cryptographic hash such as SHA-256 for security purposes.

What is the checksum of an empty input?

An empty string produces the value 1 (hexadecimal 00000001), which is the defined Adler-32 result when no bytes are processed.

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