About Fletcher-8 Checksum
The Fletcher checksum is an algorithm for computing a position-dependent checksum devised by John Gould Fletcher at Lawrence Livermore Labs in the late 1970s. The objective of the Fletcher checksum was to provide error-detection properties approaching those of a cyclic redundancy check but with the lower computational effort associated with summation techniques.
Input: binary bytes (text input uses UTF-8; a file retains its original bytes). Output: text.
Format reference: Fletcher-8 Checksum background and specification
Example
Use “Try example” to load this public sample and its settings, then run it.
Result
a6
Parameters
This tool does not need additional parameters.
Before interpreting the result
Use a checksum to compare exact bytes against a trusted digest. Choose a password hashing function for passwords and a MAC for keyed authentication. MD5 and SHA-1 are unsuitable for new security-sensitive designs.
How to use this page
- Paste your input or open a local file.
- Adjust tool options if needed, then choose Run tool.
- Copy the result or download the original output bytes.
Inputs and results are not added to the public catalogue or saved in the URL. Processing happens in your browser; HTTP Request and DNS over HTTPS send the requests you explicitly run. Files up to 128 MiB can be opened; decompression and image tools may have smaller processing limits. Large results have a shortened preview. Text and HTML downloads use UTF-8; binary downloads preserve output bytes. Pasted text follows browser newline handling; open a file when exact input bytes matter.