.log — Log File
Text text/plain
What a .log file is
Plain text output from an application or system, usually one timestamped event per line.
How to open it
Any text editor. For large files use tail -f, less, or ripgrep rather than opening the whole thing.
Worth knowing
Log files grow without bound unless rotated. A full disk from unrotated logs is a classic 3 a.m. incident.
How to identify a .log file
A file's extension is only its name — renaming a.png to a.log changes nothing inside. What software actually reads is the magic number, the first few bytes of the file.
| Signature | none |
| MIME type | text/plain |
| Category | Text |
Plain text.
# what is this file really?
file mystery.log
# look at the first bytes yourself
xxd mystery.log | head -2
head -c 16 mystery.log | xxd
# Windows PowerShell
Get-Content mystery.log -AsByteStream -TotalCount 16 | Format-HexFrequently asked questions
What is a .log file?
Plain text output from an application or system, usually one timestamped event per line.
How do I open a .log file?
Any text editor. For large files use tail -f, less, or ripgrep rather than opening the whole thing.
Is .log safe to open?
Yes. A .log file is data, not code — opening one cannot execute anything by itself.
Can I change a file's extension to convert it?
No. Renaming changes the label, not the bytes. The one place it appears to work is between formats that genuinely share a container — renaming .docx to .zip works because a DOCX is a ZIP. Everything else needs a real converter.