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Data file

What is a .log file?

A .log file is a plain-text diary written by a program — what it did, when, and what went wrong. Handy when you're troubleshooting, harmless otherwise.

This extension has been used by more than one format

2 different formats have claimed .log over the years, so two files with the same extension aren't necessarily the same kind of thing.

How to open a .log file

  • WindowsNotepad
  • WindowsNotepad++ for big files
  • WindowsVS Code
  • MacConsole
  • MacTextEdit
  • Linux`less`, `tail -f`

How to convert a .log file

  • Already text — rename to .txt if an app refuses to open it.

The technical record

For archivists, developers and the merely curious: these are the PRONOM registry entries for .log.

Format nameVersionMIME typePUID
Log Filex-fmt/62
Bluetooth Snoop Packet Capturefmt/904

Got another one?