hl is a set of command-line interface tools for filtering, aggregating, streaming, and visualizing structured log data across multiple sources. It functions as a log filter, file aggregator, real-time streamer, and structured log viewer.
The project specializes in transforming JSON and logfmt data into human-readable formats for visual analysis. It enables the merging of multiple log files and compressed archives into a single chronologically sorted stream, while supporting live tracking of multiple sources into a unified real-time view.
Capabilities include field-based filtering via key-value pairs, logical query execution, and severity level thresholds. The tool manages timestamp normalization and timezone display, allows for field visibility control to reduce visual noise, and integrates with system pagers for memory-efficient navigation of large datasets.