Ledge

How to check a file with Quick Look before you drop it on a Mac

· 6 min read

Select the file and press the Space bar. Quick Look opens a preview without launching the app that made it, so you can confirm it is the right file, and the right version, before it goes into an email, an upload or a chat. Press Space again, or Escape, to close it.

The basic habit

Wrong attachments are a very common mistake, partly because file names lie. “Final” and “final2” look alike, and a PDF named Invoice can be last month’s. A two-second preview prevents most of that.

  1. Click a file in Finder, or in a Finder-style list such as an open dialog.
  2. Press the Space bar.
  3. Read the first page, look at the image, or listen to the first moments of audio.
  4. Press Space again to close.

Quick Look works on the Desktop, in any Finder window, in the Downloads stack when you open it as a grid or list, and in most file pickers. It handles images, PDFs, Office documents, text, audio, video, and many other types. If an app has not provided a preview for its own format, you see only a big icon with the file details.

Go through several files in a row

Quick Look gets much faster once you use it on a whole folder.

  • Arrow keys. With Quick Look open, press the arrow keys to move to the next or previous file in the Finder window. The preview follows.
  • Select several first. Select a group, press Space, and use the arrow keys or the on-screen arrows to step through the selection.
  • Index sheet. With a group selected, press Space and then click the grid button in the toolbar (or press Command-Return) to see all the files as a contact sheet.
  • Full screen. Press Option-Space with Quick Look open to expand it to full screen, or Option-Space on a selected file to open it that way directly. Ledge uses Option-Space by default for its own shelf, so if you want both, change one of the shortcuts, or use the Quick Look button in the toolbar instead.

How to preview several files at once before sending them on a Mac goes deeper on reviewing a batch.

Do small fixes without opening an app

The Quick Look window has tools in its toolbar, which appear when you move the pointer over it.

  • Rotate. Click the rotate button to turn a sideways image or scan. Hold Option to rotate the other way. The change is saved to the file.
  • Markup. Click the Markup button to draw, add text, or crop an image or PDF. Click Done to save.
  • Trim. For video and audio, a trim control lets you cut the start and end. Choose Trim, drag the yellow handles, and save as a new clip or replace the original.
  • Open with. The button at the top right opens the file in its usual app when a preview is not enough.

Be careful with changes that are saved into the file. If the original matters, duplicate it first with Command-D and mark up the copy.

What Quick Look cannot tell you

A preview shows what the file looks like, and that is not always everything inside it.

  • Hidden data. A PDF or image may carry details you cannot see in the preview, such as the author name, the location a photo was taken, or earlier revisions of a document. If privacy matters, look at the file’s Get Info window (Command-I) and consider removing the details before you share it.
  • Page count and size. Quick Look shows only the page in front of you. Check the file size with Command-I as well, since upload fields have limits.
  • Formatting differences. A word-processing document can look right in Quick Look and different in the recipient’s app. If layout matters, send a PDF.
  • Locked and unsupported files. A password-protected document shows only a lock prompt, and an unknown type shows an icon.

Make the check part of the hand-off

The check works best at the moment you pick things up, not after they are in the message. If you gather files before sending, preview each as you add it. With Ledge, drag a file up to the notch and let go; it lands on a shelf that stays there until you take it somewhere. Open the shelf with Option-Space or a click on the notch, and you can review the whole collection in one place, then drag the lot to the destination. Each destination gets the format it can use: Finder moves the file, a chat app uploads it, a terminal receives the path as text. The shelf keeps files on your Mac only, with no account and no cloud. Ledge needs macOS 14 Sonoma or later and offers 14 days free. For the gathering habit, see how to collect several files before you send them.

A short checklist before you press Send:

  1. Is it the right file, and the latest version?
  2. Does the first page look right, and are there no stray pages?
  3. Is it under the size limit?
  4. Is anything in it you did not mean to share?

Questions

Why does the Space bar do nothing?

Make sure a file is selected, and that the Finder window, not a text field, has focus. In an open dialog, click the file once first. Some apps do not support Quick Look in their own lists.

Can I preview a ZIP file?

Quick Look shows a ZIP’s basic details but not the contents. Unzip a copy to look inside, or see how to extract one file from a zip on a Mac.

Does Quick Look change my file?

Not by itself. Only the rotate, Markup and trim tools change a file, and only when you save.