Adler-32 Checksum Calculator
Compute Adler-32 checksums used by zlib and PNG. Browser-only, no upload.
No uploads. No account. Free to use.
Adler-32 as used by zlib.
Drop a file
Nothing is uploaded. Processing stays on this device.
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- Files never leave your device
- Runs entirely in your browser
- No signup required
- Free
What is Adler-32 Checksum Calculator?
Adler-32 is the rolling checksum used inside zlib and many compressed formats. Calculate it privately in your browser.
Key features
- Text + file
- standard Adler-32
- instant
- client-side.
How to use it
- Input
- compute
- copy hex/decimal.
When to use it
No upload, pure JS implementation matching zlib reference.
Frequently asked questions
Adler-32 vs CRC-32?
Faster but slightly weaker error detection. Uploaded? Never.
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