How to preview several files at once before sending them on a Mac

Select the files in Finder and press the Space bar. Quick Look opens the first one, and the arrows at the top of its window, or the Left and Right arrow keys, step through the rest without opening any app. Click the button with four squares to see every selected file at once as a sheet of thumbnails.

That is usually enough to catch the classic mistakes before they leave your Mac: the draft instead of the final, the blurry photo instead of the sharp one, the scan missing its last page.

Step through a set with Quick Look

1. In Finder, select the files. Shift-click selects a run of files, Command-click picks ones that are not next to each other, and Command-A selects everything in the folder.
2. Press the Space bar, or choose File > Quick Look (Command-Y).
3. Use the arrows at the top of the Quick Look window, or the Left and Right arrow keys, to move from one file to the next.
4. Press the Space bar again, or Escape, to close it.

Quick Look shows PDFs, images, video, audio, text and many document formats as they are, and you can scroll through a multi-page document. For a format it cannot show, you get a large icon with the file’s name and details, which at least confirms which file you have.

Two buttons make it faster:

• The index sheet. With several files selected, the Quick Look toolbar has a button with four squares. Click it to see every selected file as a thumbnail on one screen, then click a thumbnail to jump to it. It is the quickest way to spot the odd one out in a batch of photos.
• Full screen. The button with two diagonal arrows fills the screen, which helps with a dense spreadsheet or a scanned page full of small print.

With a single file, Quick Look also follows your selection. Leave it open, click back in the Finder window, and use the arrow keys to move through the folder one file at a time; the preview updates as you go.

What to check before you send

A short pass catches the mistakes that are awkward to undo once a file has gone:

• Is it the final version? Names like final, final 2 and final-new are not proof of anything. Look at the content, not the name.
• Is everything there? Scroll to the last page of a PDF. Check that signature pages and appendices made it in.
• Is it the right photo? In a run of near-identical shots, the index sheet makes the sharp one obvious.
• Is anything in view that should not be? A notification in a screenshot, a second tab in a browser capture, a private note at the edge of a scan.
• Will it open for them? If Quick Look cannot show a file, the person receiving it may have trouble too. Consider exporting it to a common format such as PDF.

For details Quick Look does not show, such as an image’s dimensions or where the file lives, press Command-I for Get Info, or use the preview pane described next.

Keep a preview open beside the file list

Quick Look is a floating window you open and close. The Finder preview pane stays put beside your files.

1. In a Finder window, choose View > Show Preview (Shift-Command-P).
2. Click a file. The right side of the window shows a preview along with its kind, size and dates, and for photos the dimensions and camera details. Click Show More for the full list.
3. Use the arrow keys to move through the folder; the pane updates as you go.

The bottom of the pane offers quick actions for the selection, such as Rotate, Markup and Create PDF, depending on the file type and how many files are selected.

For photos and slides, Gallery view is often better still. Choose View > as Gallery (Command-4) for one large preview with a strip of thumbnails underneath that you can scroll through.

Fix small things without opening an app

Quick Look can make light edits, which saves a trip through another app:

• Rotate a sideways photo or scan with the rotate button.
• Markup an image or a PDF: add text, shapes, arrows or a signature with the pen button.
• Trim a video or audio clip to cut the start and the end.

These change the file itself when you click Done, not a copy. If you might need the original, duplicate it first: select it in Finder, press Command-D, and edit the duplicate instead.

Gather the ones that pass

Previewing usually ends with a few keepers scattered across folders: two PDFs in Documents, a photo in Downloads, a screenshot on the desktop. The next job is getting them all into one email or chat without opening four Finder windows.

Ledge is built for that step. As each file passes your check, drag it from the Finder window up to the notch and let go; it lands on a shelf that drops from the notch and stays there. Carry on previewing. When you have everything, open the shelf with Option-Space or a click on the notch and drag the set into the email or the chat. Each app gets the form it can use: a chat app uploads the file, a terminal gets the path as text, and a Finder window gets the file itself.

Ledge does not preview, read or index your files; it holds what you put on it, and it works without an account or any cloud. That makes the two a natural pair: Quick Look to check, the shelf to collect. How to collect several files before you send them covers more ways to put a batch together.

Questions

Why does pressing the Space bar not open Quick Look?

A file has to be selected in a Finder window or on the desktop, and Finder has to be the app in front. If the cursor is in a text field, such as the Finder search field, the Space bar just types a space. Click the file once and try again.

Is Quick Look the same as opening the file?

No. It draws a preview without launching the file’s app, so it is quicker and you cannot type into the document by accident. The exceptions are Rotate, Markup and Trim, which do change the file.

Does Quick Look work on an external drive or a network share?

Yes, as long as the drive or share is connected. Large files over a slow network can take a moment to appear.