File extensions
Show file extensions to avoid rename mistakes and understand file types.
File extensions
Explorer can show file extensions (recommended).
Why extensions matter
Extensions answer two questions instantly:
- “What kind of file is this?”
- “What will open it?”
They also prevent accidents like renaming a file and silently changing its type.
Turn extensions on/off
Open Preferences and toggle Show file extensions.
Tip: keep extensions on if you work with any of these:
- archives (
.zip,.tar.gz) - media formats (similar icons, different behavior)
- developer files (scripts, configs)
Renaming safely
If you change a filename, treat the extension as part of the file type:
- rename the name when you want a new label
- change the extension only when you intentionally change the file type
When you might hide them
If you work only with a small set of well-known types and prefer visual icons, you may choose to hide extensions - but it’s usually a productivity downgrade.