The open Command on Mac: Launch Anything From Terminal

The open command is the bridge between Terminal and the rest of your Mac. Point it at a file, folder, app, or URL and macOS handles it exactly as if you'd double-clicked — same default apps, same behavior. It's the first command worth learning because it makes every other Terminal session less of a dead end.

Start with open . — the two characters you'll use daily

The dot means "the folder I'm standing in," so this pops the current Terminal location open as a Finder window:

# open the current folder in Finder
open .

# open any folder by path
open ~/Downloads

# open a file with its default app
open budget-2026.xlsx

That last form respects your system defaults: a .pdf goes to Preview (or whatever you've set), an .html file to your default browser, and so on. If open picks the wrong app, that's a default-app problem, not an open problem — see how to change the default app for a file type.

Two details worth knowing early. open expands ~ the same way the shell does, so open ~/Library takes you straight into a folder Finder normally hides — often the fastest way in. And if the path you give doesn't exist, open says so plainly instead of failing silently, which makes it a quick way to confirm that a script's output actually landed where you expected.

Pick which app handles the file

Three flags override the default when you want a specific app just this once:

# -a: open with a specific app (use the app's name)
open -a Preview screenshot.png
open -a "Google Chrome" https://trymainspring.com

# -e: force TextEdit, handy for peeking at config files
open -e ~/.zshrc

# -t: open in your default text editor
open -t notes.md

The -a flag also works with no file at all — open -a Calculator simply launches the app. Quote names that contain spaces, and use the name as it appears in the Applications folder. If open can't find the app you named — a typo, or an app that lives somewhere unusual — it reports "Unable to find application" and does nothing, so the worst case is a harmless error message.

Because these flags affect only that one launch, there's nothing to undo: the next double-click uses your normal default again. That makes -a the polite way to test an app you're evaluating — say, opening the same image in three different editors — without committing to any of them as the default.

Reveal, URLs, and batches

A few more flags cover the rest of what open does well:

• open -R file.pdf — reveal the file: instead of launching it, Finder opens with the file selected. Perfect after a script generates output somewhere deep.
• open https://example.com — URLs launch in your default browser; mailto: links open a new message in your default mail app.
• open *.png — wildcards work, so this opens every PNG in the folder in Preview as one batch. Great for a quick flip-through of screenshots.
• open -n -a Calculator — -n forces a new instance even if the app is already running. Two Calculator windows, two timers, two of anything.
• open -g file.pdf — opens in the background without stealing focus from Terminal, so you can keep typing.

Everything composes: open -g -a Preview *.jpg loads a folder of photos into Preview while you stay in the Terminal. And because open returns immediately rather than waiting for the app to quit, it never blocks a script that calls it — which makes it a natural last line in small automations: generate a report, then open it, or open -R it so Finder shows you the result without launching anything heavier.

The reverse trip: Finder to Terminal

open . takes you from Terminal to Finder. macOS has the opposite direction built in too — a "New Terminal at Folder" service that opens a shell already cd'd into whatever folder you right-click. Set it up once in our guide to opening a Terminal window at any folder, and the round trip is complete.