How to change the default video player on a Mac

To change the default video player on a Mac, select any video file in Finder, press Command-I to open the Get Info window, select your preferred player from the “Open with:” dropdown menu, and click the “Change All…” button. Because macOS binds default applications to specific file extensions rather than video files as a general category, you must repeat this five-second process separately for each format you watch, including MKV, MP4, AVI, and WebM.

By default, macOS routes every compatible media file to QuickTime Player. While QuickTime integrates tightly with Apple hardware, it refuses to open modern open-source containers like MKV and WebM, and lacks support for legacy formats like AVI and WMV. Setting a versatile third-party player as your system default ensures that double-clicking any movie file on your desktop launches playback instantly without format errors.

Animation

How to change the default video player in macOS Finder

1. Select VideoFind MKV or MP4
2. Get InfoPress ⌘I
3. Open WithChoose your player
4. Change AllClick button
5. ConfirmApply system-wide

How do you change the default video player in macOS Finder?

Apple provides a built-in mechanism within macOS Finder to reassign default application handlers for any document type.

Follow these step-by-step instructions to configure your preferred video player:

1. Open Finder and navigate to any video file on your Mac (such as an .mp4 or .mkv movie).
2. Click the file once to select it, then press the keyboard shortcut Command-I (⌘I), or right-click the file and select Get Info.
3. In the Get Info inspector panel that appears on the left, locate the section labeled Open with:. If the section is collapsed, click the small grey arrow next to the title to expand it.
4. Click the dropdown menu showing the current default application (such as QuickTime Player) and select your target media player from the list. If your preferred app does not appear in the recommended list, scroll to the bottom, select Other…, navigate to your Applications folder, and choose it manually.
5. Directly beneath the dropdown menu, click the button labeled Change All….
6. macOS will display a confirmation dialog asking: “Are you sure you want to change all similar documents to open with the application?” Click Continue.

From this moment forward, double-clicking any file on your Mac sharing that identical file extension will immediately launch your chosen player. For additional details on Finder file handling, consult the official Apple Support guide on choosing default apps on Mac.

Why do you need to change default players for each file format separately?

A common source of confusion for Mac users is discovering that setting a default player for an MP4 video has no effect when double-clicking an MKV or MOV file.

macOS does not categorize media files under a monolithic “video” umbrella. Instead, the operating system manages document associations through Uniform Type Identifiers (UTIs), a hierarchical metadata architecture defined by Apple. Under the UTI framework, each container format is registered as an independent data type with its own unique identifier and file extensions:

Because macOS treats public.mpeg-4 and org.matroska.mkv as completely unrelated data structures as outlined in Apple’s Uniform Type Identifiers documentation, the system maintains independent default application tables for each extension.

To ensure all your media opens in your preferred player without friction, keep an example file of each primary extension in a folder and run the Get Info › Change All sequence for the big four:

1. One .mkv file (read our guide on how to play MKV on Mac)
2. One .mp4 file
3. One .mov file
4. One .avi file (learn more in our guide on playing AVI and WMV on Mac)

Completing this sequence once takes less than thirty seconds and permanently unifies your media playback experience across the entire operating system.

Why does macOS sometimes reset your default video player?

Many Mac users notice that their carefully configured default video associations occasionally revert back to QuickTime Player without warning. This unexpected behavior typically stems from one of three system triggers:

1. Major macOS System Updates

When Apple deploys a major operating system update (such as moving between macOS versions), the installation script refreshes system security policies and default application bundles. During this process, macOS frequently reinstates QuickTime Player as the primary handler for standard containers like MP4 and MOV.

2. Launch Services Cache Corruption

macOS relies on a background subsystem called Launch Services to map file types, MIME types, and filename extensions to installed application bundles. Over months of installing, updating, and deleting applications, the Launch Services database can become cluttered with orphaned bundle identifiers or contradictory handler entries, causing Finder to fall back to system defaults.

3. Application Updates and Handler Ranks

In macOS application bundles (Info.plist), developers declare their application’s relationship to file types using a property called CFBundleTypeRole and a handler rank (LSHandlerRank). If you install or update another media player that claims an “Owner” rank for video files, macOS may give that newly registered bundle temporary precedence over your prior selections.

How do you fix a corrupted Launch Services database in Terminal?

If your Mac refuses to remember default player selections after clicking Change All, or if the “Open with” context menu displays duplicate application names, you can resolve the issue by resetting and rebuilding the Launch Services database.

To rebuild Launch Services using macOS Terminal:

1. Close all active Finder windows.
2. Open the Terminal application (located in /Applications/Utilities/Terminal.app, or launch it via Spotlight by pressing Command-Space and typing “Terminal”).
3. Copy and paste the following command into the Terminal window as a single continuous line:

/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

4. Press Return to execute the command. The lsregister utility will spend 10 to 30 seconds scanning your system, deregistering stale entries, and rebuilding the application mapping index.
5. Once the command prompt reappears, restart the Finder process by entering:

killall Finder

After Finder restarts, repeat the Get Info › Change All process for your video files. With a clean Launch Services database, macOS will reliably preserve your default player assignments across reboots and system updates.

How do you set MacLC as your default video player?

MacLC registers itself with macOS Launch Services as an official viewer for all major video, audio, and subtitle formats. In the release build of MacLC, the application declares support for:

• Video Containers: MKV, MP4, M4V, MOV, AVI, WebM, MPEG-TS (.ts, .m2ts, .mts), VOB, OGG/OGV, 3GP, and FLV.
• Audio Formats: FLAC, ALAC, Opus, MP3, AAC, WAV, AIFF, and WMA.
• Subtitles and Playlists: SRT, SSA/ASS, WebVTT, M3U, and PLS playlists.

Because MacLC explicitly registers these file formats with macOS, it appears automatically in Finder’s Open With contextual menu as soon as you drag the app into your Applications folder.

To set MacLC as your universal default player:

1. Right-click any .mkv file in Finder and press Command-I.
2. Under Open with:, select MacLC from the dropdown menu.
3. Click Change All… and confirm in the alert dialog.
4. Repeat the identical steps on an .mp4 file and a .mov file.

Once configured, double-clicking any video launches MacLC instantly. MacLC relies on Apple’s VideoToolbox framework to deliver hardware-accelerated decoding directly on your Mac’s Media Engine, bypassing the format limitations of QuickTime without unnecessary CPU overhead.

Note that for .torrent files, MacLC registers with an “Alternate” handler rank rather than claiming default ownership. This ensures MacLC appears in your right-click Open With menu when you want to stream open-source torrents, while allowing dedicated download tools like Transmission or qBittorrent to retain primary association if you prefer.

What should you look for in a default Mac video player?

Choosing which application deserves to be your system-wide default video player comes down to balancing codec flexibility, system efficiency, and native macOS design.

When evaluating default players, consider three key technical criteria:

1. Hardware Acceleration Support: A default video player should offload decoding to Apple Silicon hardware blocks whenever possible. Playing high-bitrate 4K HEVC or AV1 files in software decoders quickly drains laptop battery life and generates unnecessary fan noise. Compare performance trade-offs in our review of VLC for Mac.
2. Native AppKit Architecture: Cross-platform media hubs frequently implement custom drawing loops that ignore macOS window snapping, keyboard shortcuts, and menu bar standards. A great Mac player should feel like an organic extension of macOS, supporting Dark Mode, full keyboard navigation, and picture-in-picture playback.
3. Container and Audio Compatibility: The primary motivation for replacing QuickTime is eliminating the frustrating “QuickTime Player can’t open this file” alert. Your default player should decode modern containers (MKV, WebM), multichannel audio (AC-3, E-AC-3, DTS), and styled subtitles (ASS/SSA) out of the box without requiring external plugins or conversion utilities.

To compare how the top macOS media players stack up against these requirements, explore our comprehensive guide to the best video players for Mac.

Take permanent control of your media playback

Setting your default video player is one of the most practical quality-of-life adjustments you can make on macOS. By taking thirty seconds to assign your primary video extensions in Finder’s Get Info inspector, you eliminate the hassle of format compatibility dialogs and secondary contextual menus.

Choosing a capable utility like VLC or a modern Apple Silicon player like MacLC and configuring your defaults ensures that your films, television episodes, and personal recordings play immediately every time you double-click a file.