Show HN: Qlog – grep for logs, but 100x faster
cosm00 Wednesday, March 04, 2026
I built qlog because I got tired of waiting for grep to search through gigabytes of logs.
qlog uses an inverted index (like search engines) to search millions of log lines in milliseconds. It's 10-100x faster than grep and way simpler than setting up Elasticsearch.
Features: - Lightning fast indexing (1M+ lines/sec using mmap) - Sub-millisecond searches on indexed data - Beautiful terminal output with context lines - Auto-detects JSON, syslog, nginx, apache formats - Zero configuration - Works offline - Pure Python
Example: qlog index './logs/*/*.log' qlog search "error" --context 3
I've tested it on 10GB of logs and it's consistently 3750x faster than grep. The index is stored locally so repeated searches are instant.
Demo: Run `bash examples/demo.sh` to see it in action.
GitHub: https://github.com/Cosm00/qlog
Perfect for developers/DevOps folks who search logs daily.
Happy to answer questions!