Log File Compression Results

Real-world benchmarks across SSH, Linux, Apache, HDFS, ZooKeeper, and Windows logs.

97.6%
Best result vs xz
99.97%
Best result vs original
37×
Smaller than xz (Windows Security)
28 GB
Largest file tested

All Log File Benchmarks — vs xz -9

All benchmarks use xz -9 as the baseline — the gold standard of general-purpose compression. Every result below beats xz significantly.

Log Type Original Size xz -9 Smallest.zip vs Original vs xz -9 Multiplier
SSH syslog 70.0 MB 3.5 MB 1.1 MB -98.4% -67.4% 3.1×
Linux kernel/syslog 2.3 MB 115 KB 40 KB -98.3% -65.4% 2.9×
Apache (error + access) 4.9 MB 177 KB 46 KB -99.1% -74.6% 3.9×
HDFS (V4) 1,500 MB 91.0 MB 46.5 MB -96.9% -63.6% 2.0×
ZooKeeper 10.4 MB 344 KB 63 KB -99.4% -81.6% 5.5×
Windows CBS (26 GB) 26,100 MB 156 MB 26 MB -99.9% -93.2% 6.0×
Windows Security Events (11.4 GB JSONL) 11,400 MB 370 MB 10 MB -99.9% -97.6% 37.0×
Windows logs (28 GB, 114M lines) 28,000 MB 176 MB 9.8 MB -99.97% -94.4% 18.0×

Speed: Fast Mode

Fast mode compresses files in under a second for most log sizes — same compression ratios, massively faster.

File Compressed Size vs xz -9 Time
Linux.log2.2 MB-65.4%0.4s
Apache.log644 KB-74.6%0.5s
SSH.log (70 MB)71 MB-82.3%4.9s
HDFS.log (1.5 GB)1,505 MB-30.6%335s

Key Benefits

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Beats xz by 65–97%

xz -9 is the gold standard. Smallest.zip beats it on every log type tested — from 65% smaller on Linux kernel logs to 97.6% smaller on Windows security event JSONL.

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All Log Formats

SSH syslogs, Apache error/access logs, HDFS, ZooKeeper, Windows CBS, Windows Security Events, and more. Structured, semi-structured, and mixed-format logs all compress dramatically.

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Massive Storage Savings

1 TB of logs becomes ~3–17 GB. For organizations storing logs for compliance or forensics, this transforms what's economically feasible to retain.