Zlib data usually starts with specific "magic bytes" (like 78 9C ). If these are missing, the tool might fail.
Before we dive into the "how," let's understand the "what." zlib is a lossless data compression format. It wraps around the DEFLATE algorithm (which combines LZ77 and Huffman coding) but adds a small header and a checksum footer (Adler-32). zlib decompress online free