Fix Preview Not Working on Mac: Troubleshooting Guide

As a macOS expert, I‘ve seen my fair share of software bugs. Among the most common issues is when Preview, the default image and PDF viewer on Mac, stops working properly. This can manifest in several ways:

• Preview fails to launch and bounces in the Dock
• Previews opens but crashes when trying to view a file
• Images or PDFs appear blank, distorted, or don‘t render properly
• Editing tools in Preview are grayed out or don‘t work

When a core app like Preview malfunctions, it can really grind your workflow to a halt. Don‘t panic – in most cases, there‘s a logical reason and a workable solution.

In this guide, I‘ll walk through the 4 most common culprits behind Preview woes and 7 troubleshooting steps to get it running smoothly again. Whether you‘re a novice or power user, these tips should help you diagnose and resolve Preview issues.

Why is Preview Not Working?

Based on my experience and scouring Apple discussions, here are the top 4 reasons Preview stops working properly on Mac:

1. Corrupted Preview Preferences

The most common cause of Preview misbehavior is a bad preference file. Like all Mac apps, Preview stores settings in a .plist file. If this file gets corrupted, it can cause Preview to crash, freeze, or just fail to launch.

Preference file corruption often happens after a macOS update or if your Mac shuts down unexpectedly. Fortunately, it‘s an easy fix. I‘ll show you how to reset Preview preferences shortly.

2. Conflict with Login Items or Extensions

Another frequent reason for Preview glitches is a conflict with third-party extensions or login items. Things like PDF editing plug-ins, custom dictionaries, and startup apps can sometimes interfere with Preview‘s normal operations.

To rule out a conflict, restarting your Mac in safe mode is a good troubleshooting step. This prevents extensions and login items from loading so you can isolate the issue. Instructions coming up.

3. Bug in macOS Update

In rare cases, a bug introduced in a macOS update can cause Preview to malfunction. While Apple is usually quick to patch these bugs in a subsequent update, it can be maddening to encounter one.

I always recommend keeping your Mac up-to-date to make sure you have the latest bug fixes and security patches. However, if you recently updated macOS and Preview suddenly stopped working, you may need to sit tight for a fix from Apple.

4. Hardware Issue

The least likely reason for Preview issues, but worth mentioning, is a hardware problem like a failing graphics card or logic board. If Preview is showing visual artifacts or crashing, and you‘ve ruled out software causes, there could be a physical defect.

Hardware issues are rare these days, especially on newer Macs. But if your Mac is long out of warranty and experiencing strange glitches, it warrants an evaluation at the Genius Bar or an authorized Apple repair shop.

7 Ways to Fix Preview Not Working on Mac

Now that we‘ve covered the potential causes, let‘s get into troubleshooting. Here are 7 solutions to try, from easiest to most drastic:

1. Force Quit Preview

If Preview is frozen or unresponsive, you can force it to quit and relaunch:

1. Press Command+Option+Esc to open the Force Quit menu.
2. Select Preview and click Force Quit.
3. Relaunch Preview from the Dock or Applications folder.

2. Reset Preview Preferences

Deleting the Preview .plist file will reset its preferences to default and often resolves strange behavior:

1. Quit Preview completely.
2. In the Finder, click Go > Go to Folder.
3. Type ~/Library/Preferences and click Go.
4. Find com.apple.Preview.plist, move it to the Trash, and empty the Trash.
5. Relaunch Preview.

3. Boot in Safe Mode

Restart your Mac in safe mode to isolate the Preview issue:

• Intel Mac: Restart and hold the Shift key until you see the login screen.
• M1 Mac: Shut down, press and hold power button, select startup disk, hold Shift and click "Safe Boot."

If Preview works in safe mode, a third-party extension is likely the culprit. Restart normally, then remove suspect extensions one by one until you find the conflict.

4. Check for Software Updates

As mentioned, Apple often patches Preview bugs in macOS updates. To check for and install the latest:

1. Click the Apple logo and select System Preferences.
2. Go to Software Update.
3. If an update is found, click Update Now.
4. Restart after installing and test Preview again.

5. Remove Conflicting Extensions

Besides restarting in safe mode, you can test for extension conflicts by manually removing them:

1. In the Finder, click Go > Go to Folder.
2. Type /Library/Internet Plug-Ins and click Go.
3. Move suspect plug-ins (like for PDF editing) to the desktop.
4. Restart your Mac.

You can also check the extensions in ~/Library/Internet Plug-Ins. Move them out one by one until Preview works, then you know which was causing issues.

6. Test in New User Account

To rule out an account-specific issue, create a new user account for testing:

1. Go to System Preferences > Users & Groups.
2. Click the "+" button to add a new user.
3. Log into the new account and launch Preview.

If Preview works in the test account, the problem is isolated to your main account. You may need to migrate to a fresh account to resolve it.

7. Reinstall macOS

As a last resort, you can reinstall macOS on top of your existing installation to replace any corrupt system files:

1. Restart your Mac in Recovery mode (Command+R at startup).
2. Choose "Reinstall macOS" in the Recovery Utilities window.
3. Follow the prompts to download and install the latest macOS version.

This won‘t delete any of your files, but it‘s a good idea to back up before reinstalling just in case.

Still Stuck? More Resources

If you‘ve tried all of the above and Preview still isn‘t cooperating, don‘t despair. There are a few other avenues for information and assistance:

• Search or post on the official Apple Support Community forums. Chances are someone has encountered your issue before.

• Use the Console app (in Applications > Utilities) to view error messages and system logs. While Console can be cryptic for the average user, it often provides clues for additional research.

• Open a support ticket with Apple online or call their support line. If your Mac is under warranty or AppleCare, you may qualify for free assistance.

• Take your Mac to an Apple Store or authorized repair shop for diagnosis. A technician can run hardware tests and check for deeper software problems.

Preview Alternatives for Mac

While I strongly believe every Mac user should know how to troubleshoot the default Preview app, sometimes you just need to get work done while waiting for a fix. Here are some popular (and free) Preview alternatives:

• Adobe Acrobat Reader DC for viewing and annotating PDFs
• XnView MP for browsing and editing images
• Skim for reading and marking up PDFs and academic papers
• GIMP for more advanced image editing

Most of these are available in the Mac App Store, or directly from the developer‘s website. Just be aware of any upgrade costs or subscription pricing.

Final Thoughts

I hope this in-depth guide to fixing Preview issues on Mac has been enlightening and empowering. Troubleshooting can feel intimidating, but approached step-by-step with a calm head, it‘s a rewarding process that can teach you a lot about your Mac.

If there‘s one thing I‘ve learned as an expert, it‘s that you‘re rarely alone in your computing struggles. Don‘t hesitate to use official and community resources – even if you can‘t find your exact issue, you‘ll improve your understanding and ability to resolve future challenges.

At the end of the day, Preview is just one (albeit important) app in the grand macOS ecosystem. Knowing how to diagnose it is an essential skill, but don‘t forget to periodically evaluate your workflow and explore alternatives. The best tools are the ones that keep you productive and reduce friction.

Here‘s to your continued mastery of macOS! May all your Previews be smooth and glitch-free.

Credit to the following sources for technical information and solutions:

• Apple Support, "Preview App: Resolve issues viewing or editing files"
• MacRumors, "Preview Not Working on Mac – Fix"
• OSXDaily, "How to Reset Preview Preferences"
• Mac Geek Gab Podcast, Episode 281