Adler-32 Hash Code Calculator

The Adler-32 hash function is a checksum algorithm that is simple, fast, and often used for data integrity verification. It was designed by Mark Adler and is commonly used in applications like zlib for data compression. Unlike cryptographic hash functions (like SHA-256), Adler-32 is not designed for security but for quick error-checking. It computes a 32-bit (4 bytes) checksum, usually represented as 8 hexadecimal characters.

Full disclosure: I did not write the specific implementation of the hash function used on this page. It is a standard function included with the PHP programming language. I only made the web interface to make it publicly available here for convenience.

About the Adler-32 Hash Algorithm

I'm not a mathematician, but I'll try to explain this hash function using an everyday analogy that I hope my fellow non-mathematicians can understand. Unlike many of the cryptographic hash functions, Adler32 is a quite simple checksum function, so this shouldn't be too bad ;-)

Imagine you have a bag of small numbered tiles, each representing a letter or part of your data. For example, the word "Hi" has two tiles: one for "H" and one for "i".

Now, we’re going to do two simple things with these tiles:

Step 1: Add Them Up (Sum A)

• Start with the number 1 (just as a rule).
• Add the number from each tile to this total.

Step 2: Keep a Running Total of All the Sums (Sum B)

• Every time you add a new tile's number to Sum A, you also add the new value of Sum A to Sum B.
• It's like stacking coins: you add one coin on top (Sum A), and then you write down the new total stack height (Sum B).

At the end, you glue the two totals together to make a single big number. That big number is the Adler-32 checksum.