Qlog – grep for logs, but 100x faster
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"…
In plain words
Qlog is a command-line tool for searching through large log files using an inverted index, delivering results in milliseconds rather than seconds. Built for developers and DevOps engineers working with gigabytes of logs, it automatically detects common formats like JSON, syslog, nginx, and apache logs with zero configuration. The tool works entirely offline, stores indexes locally for instant repeated searches, and requires only Python—making it a simpler alternative to setting up Elasticsearch while maintaining sub-millisecond search performance.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
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!
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