Everything We Know About the MTG Arena Log File in 2026

Most of what's been written about the Arena log format is outdated. Here's what it actually looks like. MTG Arena is the free-to-play digital version of Magic: The Gathering. When I started building a companion tool and needed to parse the Arena log file , I based my initial design on existing community documentation. About half of my assumptions turned out to be wrong. API method names I pulled from older parsers didn't exist in real logs. Game result detection worked differently than documented. A field I expected to be nested inside another was actually its sibling. An entire parser module I wrote had to be deleted because the log event it targeted doesn't appear in real Player.log files. Parser projects from 2019–2022 documented a format that has changed substantially since, and community gists reference API endpoints that were removed years ago. This post is what I wish existed when I started. Everything here has been verified against current Arena logs as of early 2026. Log File