How to AirPlay an MKV file from your Mac to your TV

You have an MKV file on your Mac and an AirPlay TV. QuickTime Player won't open it, and the TV app won't play it. Here are three ways to get it on the big screen.

Why MKV doesn't just work

When a Mac sends a video over AirPlay, your TV plays the file itself. AirPlay TVs expect the formats Apple uses: usually H.264 or HEVC video with AAC audio, in an MP4, MOV or M4V file. MKV is a different container, and it often holds audio and subtitles your TV can't read. So the Mac either refuses to send it, or your TV shows an error.

1. Mirror your screen (free, lower quality)

1. Open the MKV in a player that reads it, such as VLC or IINA.
2. Click Control Center in the menu bar, then Screen Mirroring, and choose your TV.
3. Make the video full screen.

This sends a recording of your whole screen, not the file. The picture is softer than the original, notifications and anything else on screen show up on your TV, and you can't use your Mac for other things while you watch.

2. Convert it to MP4 first (free, slow)

1. Convert the file to MP4 with a free converter such as HandBrake.
2. Open the MP4 in QuickTime Player, click the AirPlay button in the playback controls, and choose your TV.

The result looks good, but converting a full-length film can take a long time and uses extra disk space. Subtitles need care: a converter may drop them unless you choose to keep them.

3. Use an app that converts as it plays

Some Mac apps convert the file while it plays and send your TV a stream it understands. You press Play and it starts in a few seconds, with no file to convert first. Snork is one of them.