Finder hides file extensions — you can't tell if something is a .jpg, .png, or .pdf just by looking
Every file in Finder just shows its name with no extension. "Document" could be a Word file, a PDF, or a Pages file — you can't tell without opening it or doing Get Info. Especially painful when you're dealing with multiple file types that look identical.
Why does this happen?
macOS hides file extensions by default to present a cleaner interface. The OS uses file type metadata to determine which app opens a file, so extensions aren't strictly required. But for anyone who works with files regularly, this is genuinely confusing.
How to fix it
In Finder, go to Finder menu → Settings → Advanced tab.
Check Show all filename extensions.
Extensions will now appear for all files across Finder.
You can also show/hide extensions for individual files: right-click → Get Info → uncheck Hide extension.
Discussion
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