Free Online Tool

Reed-Solomon

Encode, introduce symbol errors, and restore data with Reed-Solomon correction over GF(256).

Reed-Solomon Error Correction

Systematic RS(n,k) encoding and multi-symbol correction over GF(256)

Operation

Input type

Parity symbols

Introduce a symbol error in the transmitted codeword

Data text

Transmitted codeword (hex)

Example Values

Click an example to load it.

Hello

UTF-8 text with four parity symbols

Correct me!

A longer UTF-8 message

RS(255, k)

Letters, digits, and punctuation

How to Use Reed-Solomon

Choose Text input and Encode mode.
Leave parity symbols at the default 4; text is first converted to UTF-8 bytes.
The component appends four GF(256) parity bytes and displays the systematic codeword as lowercase hex.
Optionally introduce a symbol error, then use the transmitted codeword as decoder input.
Decode locates and corrects up to two symbol errors with four parity symbols, reports their positions, and restores the data.

The decoder uses syndrome calculation, Berlekamp–Massey, Chien search, and Forney magnitudes. A GF(256) codeword is limited to 255 symbols.

Four parity symbols — input:

Hello

Output:

48 65 6c 6c 6f 92 98 cb 83

Four parity symbols — input:

Output:

52 53 5b cf 96 03

All processing happens in your browser. No data is sent to servers.

No registration, no limits, completely free to use.