A plist file stores settings and data for Mac and iOS apps in a structured format

A plist (short for "property list") is a file that holds configuration settings, preferences, and data in a way that Mac and iOS apps can read and write. Think of it as a filing cabinet where an app stores information about how you want it to behave — your font size preference, window position, login credentials, app-specific data, or system settings. When you change a setting in an app and close it, that change gets saved to a plist file so the app remembers your choice the next time you open it.

Plist files are text-based, which means you can open and read them if you know where to look, though most people never need to. They use a standardized format that both Macs and iPhones understand, which is why Apple chose this system across its entire ecosystem. The file extension is usually .plist, though sometimes these files have no visible extension at all.

Key Takeaways

  • Plist files store app settings and preferences so your Mac or iPhone remembers your choices between sessions.
  • Most plist files live in hidden folders in your home directory, particularly in the Library folder, and you rarely need to touch them.
  • You can view plist files by opening them with a text editor or the Property List Editor app, but changing them incorrectly can break an app.
  • Backing up your plist files before troubleshooting an app problem protects you if you need to restore the original version.

Where plist files live on your Mac

Plist files are stored in hidden folders that you do not see by default when you open Finder. Most of them sit inside the Library folder in your home directory. To find them, open Finder, press Command+Shift+Period (the period key) to show hidden files, then navigate to your home folder and look for a folder called Library. Inside Library, you will find a Preferences folder — this is where most app plist files live.

System-wide settings also have plist files, and those live in /Library/Preferences or other system folders. You do not need to know the exact location of every plist file; the important thing is understanding that they exist in predictable places and that your Mac keeps them organized. If an app is misbehaving and you want to reset it to factory settings, deleting its plist file from the Preferences folder will often do the job, since the app will create a fresh one with default settings the next time it launches.

How to open and read a plist file

The simplest way to view a plist file is to right-click it in Finder, select "Open With," and choose a text editor like TextEdit or a code editor. The file will open as readable text, though the formatting may look cluttered at first. You will see tags and structure that tell the app how to interpret the data — this is the plist format at work.

If you want a cleaner view, use the Property List Editor app, which comes built into Macs. Search for it in Spotlight (Command+Space, then type "Property List Editor") and open it. Then use File > Open to browse to your plist file. The Property List Editor displays the contents in a tree structure that is easier to read than raw text. This is the safest way to view plist files if you are curious about what is inside them.

When and why you might edit a plist file

Most people never edit plist files directly. However, troubleshooting an app sometimes requires it. If an app crashes on launch or behaves strangely, deleting its plist file forces the app to start fresh with default settings. This solves many problems that would otherwise require reinstalling the entire app.

Advanced users and developers sometimes edit plist files to change settings that are not exposed in an app's preferences menu. For example, you might edit a plist to change hidden options or to configure behavior that the app does not let you adjust through its normal interface. This is not something you should attempt unless you have specific instructions from a trusted source, because incorrect changes can prevent an app from launching.

Backing up plist files before troubleshooting

If you plan to delete or edit a plist file to fix an app problem, make a copy first. Locate the plist file in Finder, right-click it, and select "Duplicate." This creates a backup with the word "copy" in the filename. Store it somewhere safe, like your Desktop or a folder you create for backups. If the change does not fix the problem or makes things worse, you can restore the original by dragging the backup back to its original location.

This straightforward step protects you from having to reinstall an app or reconfigure settings from scratch. It takes thirty seconds and has saved countless people from unnecessary frustration when a troubleshooting step does not work out as expected.

The difference between plist and other file formats

Plist files are specific to Apple systems, which is why you see them on Macs and iPhones but not on Windows or Android devices. Other operating systems use different formats to store app settings — Windows uses the Registry and .ini files, while Linux systems often use plain text configuration files. The plist format was designed to be straightforward, human-readable, and standardized across Apple's entire product line.

You might also encounter plist files in different encodings: XML (text-based and readable), binary (compressed and not human-readable), and JSON (another text format). Most plist files you encounter will be XML or binary, and you do not need to know the difference to work with them. The Property List Editor and most text editors handle all formats automatically.

What happens if you delete a plist file

Deleting a plist file does not harm your Mac or the app itself. The worst that happens is the app loses its stored settings and preferences. The next time you launch the app, it will create a brand-new plist file with default settings. You will need to reconfigure any preferences you had customized, but the app will work normally. This is actually a useful troubleshooting step when an app is crashing or behaving erratically.

The only exception is if you delete a system-level plist file that controls core Mac behavior. This is rare and would require you to deliberately navigate to system folders and delete something you do not recognize. For app-specific plist files in the Preferences folder, deletion is safe and reversible — you can always restore from your backup or reconfigure the app.

Frequently Asked Questions

Can I edit a plist file while the app is running?

You can edit the file, but the app will not see the changes until you close and reopen it. The app reads the plist when it launches and writes to it when it closes. If you edit the file while the app is open and then close the app, your edits may be overwritten by what the app saves. Always close the app first, make your changes, then reopen it.

What if I cannot find the plist file for an app?

Make sure hidden files are visible by pressing Command+Shift+Period in Finder. Then navigate to your home folder, open Library, and look in Preferences. If you still cannot find it, the app may not have created a plist yet — try opening the app and changing a setting, then close it. The plist should appear after that.

Is it safe to delete plist files for system apps like Mail or Safari?

Yes, it is safe. Deleting the plist will reset that app to its default state, and you will lose your customized settings. However, it will not damage your data — Mail will still show your messages, and Safari will still show your bookmarks. You will just need to reconfigure preferences like font size, window position, and other options.

Why are plist files hidden by default?

Apple hides them because most users do not need to see or touch them. They are system-level configuration files that work behind the scenes. Hiding them keeps your home folder clean and prevents accidental deletion or modification. You can show them anytime with Command+Shift+Period, but most people leave them hidden.