View and edit files with Quick Look on Mac
Quick Look offers a fast, full-size preview of nearly any kind of file without opening the file. You can rotate photos, trim audio and video clips, and use Markup — directly in the Quick Look window.
Tip: Use Quick Look for items in Finder windows, on your desktop, in emails and messages, and other places.
On your Mac, select one or more items, then press the Space bar.
A Quick Look window opens. If you selected multiple items, the last item you selected is shown first.
In the Quick Look window, do any of the following:
Resize the window: Drag the corners of the window. Or click
in the top-left corner of the Quick Look window. To exit full screen, move the pointer to the bottom of the window, then click 
. Zoom in and out of an item: Press Command-Plus (+) to make the image bigger or Command-Minus (–) to make it smaller.
Rotate an item: Click
or press and hold the Option key, then click 
. Keep clicking to continue rotating the item. Mark up an item: Click
. See Mark up files.Trim an audio or video item: Click
, then drag the yellow handles in the trimming bar. To test your changes, click 
. To start again, click Revert. When you’re ready to save your changes, click Done, then choose to replace the original file or create a new one.Browse items (if you selected multiple items): Click the arrows near the top-left of the window or press the Left Arrow or Right Arrow key. In full screen, click
to view the items as a slideshow.Show items in a grid (if you selected multiple items): Click
or press Command-Return.Open an item: Click Open with [App].
Share an item: Click
, then choose how you want to share the item.Copy the subject of an item: If the item is a screenshot or photo, you can isolate the subject of the picture from the background. Control-click the image, then choose Copy Subject. You can now paste the subject into a document, email, text message or note.
When you’re done, press the Space bar or click
to close the Quick Look window.
When you open a Live Photo in the Quick Look window, the video portion of the photo plays automatically. To view it again, click Live Photo in the bottom-left corner of the photo.