Logfmt

lastmod 2026-11-10created 2025-12-042 edits

Logfmt is a structured log format that lists key=value pairs separated by spaces. It aims for a middle ground that is easier for people to read than JSON and easier for machines to parse than plain-text logs; it is widely used at Heroku and supported by many logging libraries in the Go ecosystem. Tools such as humanlog and hl can pretty-print it in the terminal.