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Can't Open a File

How to fix files that won't open, show the wrong app, or give errors about no application being set

When a file will not open, it is usually one of these: no app installed that handles that file type, the wrong app is set as the default, the file is corrupted, or the file extension is wrong or hidden. Here is how to figure out which one it is and fix it.

Use "Open With" to pick an app:

  1. Right-click (or Control + click) the file
  2. Select Open With and choose an app from the list
  3. If the right app is not listed, click Other to browse all installed apps
  4. To make that app the permanent default for this file type, select the file, press Cmd + I to open Get Info, expand the Open with section, choose your app, and click Change All

For a full walkthrough of changing defaults for all file types, see default apps.

No app installed for the file type:

  1. Look at the file extension (the part after the dot, like .docx or .csv). If you cannot see it, select the file, press Cmd + I, and check the Name & Extension field in Get Info
  2. Common file types and what opens them:
    • .pdf — Preview (built-in) or any PDF reader
    • .docx, .xlsx, .pptx — Microsoft Office, Pages/Numbers/Keynote, or LibreOffice
    • .csv — Numbers, Excel, or any text editor
    • .zip — double-click to extract with the built-in Archive Utility
    • .dmg — double-click to mount the disk image (this is how Mac apps are often distributed)
    • .heic — Preview opens these natively; if sharing to a non-Apple device, convert to JPEG first
    • .webp — Preview on macOS Ventura and later; older versions need a third-party viewer
    • .exe — this is a Windows program and will not run on Mac natively
  3. If you do not have an app for the file type, search the App Store or web for an app that handles that extension

File might be corrupted:

  1. Try opening the file with a different app — right-click, Open With, and pick an alternative
  2. If you downloaded the file, try downloading it again — partial downloads are a common cause
  3. If someone sent you the file, ask them to send it again
  4. For ZIP files that fail to extract, try using The Unarchiver (free from the App Store) instead of the built-in tool

File extension is hidden or wrong:

  1. Select the file and press Cmd + I to open Get Info
  2. Uncheck Hide extension to see the real file extension
  3. If the extension looks wrong (for example, a photo named image.pdf that should be image.jpg), rename it with the correct extension — macOS will warn you about changing extensions, click Use .jpg (or whatever the correct extension is)

Frequently Asked Questions

What does "There is no application set to open the document" mean?▾

It means your computer does not know which app to use for that file type. Either no app is installed that can handle it, or the file association was lost (sometimes after an app update or uninstall). Right-click the file, use Open With to pick an app, and set it as the default to fix it permanently.

Can I open a .exe file on Mac or Linux?▾

Not natively. .exe files are Windows executables. On Mac, you can use Parallels, VMware Fusion, or CrossOver to run some Windows programs. On Linux, Wine can run many Windows apps. But compatibility varies — not everything works, and it is usually better to find a native alternative for your platform.

Why does the wrong app keep opening my files?▾

Your default app for that file type is set to something you did not intend. On Mac, select the file, press Cmd + I, change the app under Open with, and click Change All. On Windows, right-click the file, choose Open with > Choose another app, check Always use this app, and click OK. On Linux, right-click, go to Properties > Open With, and set the correct default.

How can I tell if a file is actually corrupted?▾

Try opening it with a different app — if multiple apps fail, the file is likely corrupted. For archives, most extraction tools have a test or verify option. You can also compare the file size to what you expect — a 0 KB file or one much smaller than expected is probably a failed download. Re-downloading from the original source is the simplest fix.

Is it safe to change a file extension?▾

Changing the extension does not change the file's actual contents — it only changes which app tries to open it. If the extension is genuinely wrong (someone named a JPEG as .pdf by mistake), renaming it to the correct extension fixes the problem. But if the file really is a PDF and you rename it to .jpg, it still will not open as an image. Use the file command on Mac/Linux or try opening with a known-compatible app to figure out what the file actually is.