A buffer is a fixed block of raw bytes. Write Luau on the left (buffer.writeu16(b, 4, 513)) and every read and write is drawn byte by byte on the right - step through it, click any byte to see it as a u8, i32, f32 and more, and describe a struct to decode it. Or switch to Raw bytes and paste hex, decimal, binary, text or Base64 from anywhere. The Luau runs in your browser; nothing is sent to a server.

Supports the real buffer library (create, fromstring, tostring, len, read*/write* for i8-f64, readstring, writestring, copy, fill, readbits, writebits) plus bit32, most of string, math, table, loops, functions and string interpolation. Buffers are little-endian, exactly like Roblox. It is a Luau subset, not the real VM: no require, services or Roblox instances.