Hellishly Slow Level 13 Deflate Compression
Summary
An in-depth look at DEFLATE level 13, a deliberately slow but potentially smaller compression level implemented in libdeflate. Level 13 spends significant time on parse, Huffman, and block-split decisions, yielding only a 0.134% size reduction on the Silesia corpus while increasing encoding time by about 56x. The article explains why such a level exists, its mechanics, and when it might be appropriate to use it in data compression workflows.