MKV to M4R Converter

MKV to M4R: A Ringtone From a Matroska Video

An MKV file is a Matroska container, an open format that can carry a video track, several audio tracks, subtitles, chapter markers and even font attachments in a single file. That flexibility is why movie and series rips, anime releases and many OBS screen recordings end up as .mkv. Your iPhone has no use for any of that when it rings. It wants an .m4r: AAC audio in an MPEG-4 container, with the extension that tells iOS, the Finder and iTunes the file is a tone rather than a song. This converter takes one audio track out of the MKV, re-encodes it to AAC and writes the .m4r; the picture, subtitles and chapters are dropped. Use Trim to keep only the part you want ringing, because Apple says custom ringtones can be up to 30 seconds long.

How to Convert MKV to M4R

1. Upload Your MKV File: Drag the .mkv onto the page or click "Add Files". You can queue several files in one batch, and the page works in phone and tablet browsers too.
2. Set the Clip with Trim: Open Advanced Options, turn on Trim, enter the Start time where the ringtone should begin and a Duration of 30 seconds or less. Both fields take plain seconds or HH:MM:SS.sss.
3. Choose Bitrate and Channels (Optional): Audio Codec is AAC, the only codec M4R uses. Under File Compression pick Constant Bitrate (8-384 kbps), Variable Bitrate, Custom Bitrate or a target file size, and set Audio Channel to Stereo to fold a 5.1 movie track down to two channels.
4. Convert and Download: Click Convert and save the .m4r, free and with no sign-up or watermark. Copy it to your iPhone and choose it in Settings > Sounds & Haptics > Ringtone.

Which Audio Track Ends Up in the Ringtone

A ringtone is a single audio stream, so only one of the MKV's tracks can go into it. The converter uses the file's default audio track, the one a player starts with, which is usually the first. On a release with a Japanese track flagged as default and an English dub second, you get the Japanese audio. Check before uploading: in VLC, Audio > Audio Track lists every track and marks the one that is playing. If the default is the wrong one, a Matroska editor such as MKVToolNix can change the default flag without re-encoding anything, and the converter will then pick up the track you chose.

Movie MKVs often carry 5.1 surround in AC-3, E-AC-3 or DTS, or a lossless track in FLAC or TrueHD. A phone has at most two speakers, so set Audio Channel to Stereo and the surround mix is folded into two channels, centre-channel dialogue included. A lossless source gives the AAC encoder clean material to work from, but the ringtone is still lossy AAC, which is entirely adequate for 30 seconds through a phone speaker.

Picking the Right 30 Seconds

Find the moment in a player first. VLC, IINA, QuickTime and the Windows Media Player app all show elapsed time; note the second where the theme, riff or line begins and use it as the Trim Start. A few habits make a better tone:

• Start slightly early. A tone that begins mid-note sounds clipped; half a second of lead-in is enough.
• Prefer music without dialogue on top. Film mixes often lay effects and speech over the score, and that clutter is more obvious on a small speaker.
• Keep Duration at 30 seconds or under. The Trim panel on this page shows a note under Duration saying the same thing.
• Fine-tune on a waveform if you need to. Export a slightly longer stretch around the moment, then open it in the M4R trimmer, pick the exact start and end visually and save a 30-second version.

MKV vs M4R at a Glance

Ringtone Size by AAC Bitrate

Size is simple arithmetic: bitrate in kbps multiplied by seconds, divided by 8, gives kilobytes. For a 30-second tone at Constant Bitrate:

Variable Bitrate, with five AAC bands from 20k-32k up to 96k-112k, is the alternative when you would rather the encoder spend bits where the music needs them; treat the band labels as nominal, since the final size depends on the material. Custom Bitrate takes any figure you type, and the target file size option works backwards from a size you name.

Getting the M4R Onto Your iPhone

The usual routes are:

• With a Mac (macOS Catalina or later): connect the iPhone, select it in the Finder sidebar and drag the .m4r onto it. On Windows, iTunes does the same job. The tone should then be listed in Settings > Sounds & Haptics > Ringtone.
• With only the iPhone: save the .m4r to the Files app, import it into GarageBand on the iPhone and use Share > Ringtone. That is the route Apple documents in Create a custom ringtone on your iPhone; GarageBand shortens a longer tone automatically, and the audio must not be DRM-protected.
• Setting it: choose the tone in Settings > Sounds & Haptics > Ringtone, or give one person their own tone under Contacts > the contact > Edit > Ringtone or Text Tone.

Frequently Asked Questions

Does the M4R keep any of the MKV's video?

No. An M4R holds one AAC audio track and nothing else, so the video, subtitles, chapters and attachments are all left behind. If you want the same audio as a regular music file rather than a tone, MKV to M4A writes it with the .m4a extension instead.

Which audio track is used from a multi-language MKV?

The MKV's default audio track, which is usually the first. If you want another language or a commentary track, make it the default in a Matroska editor such as MKVToolNix before uploading; the tracks themselves are not touched, only the flag.

How long can an iPhone ringtone be?

Apple's support article says "ringtones can be up to 30 seconds long", and the GarageBand for iPhone guide gives 30 seconds as the maximum length for exported ringtones. You may still see a 40-second limit quoted from the iTunes era; that figure is not in Apple's current documentation, so keep the Trim Duration at 30 seconds or less.

Is an M4R just an M4A with a different extension?

Essentially, yes. Both are AAC-LC audio in an MPEG-4 container. We write M4R with ffmpeg's ipod muxer, the same one used for M4A, and ffprobe reports AAC LC in an MP4 file with major brand M4A . The .m4r extension is what tells iOS, the Finder and iTunes to treat the file as a ringtone.

Can I simply rename my .mkv to .m4r?

No. Matroska and MPEG-4 are different containers, and the audio inside an MKV is often AC-3, DTS or Opus rather than AAC. Renaming leaves the inside of the file unchanged, so the iPhone will not accept it as a tone. A real conversion extracts the track and re-encodes it to AAC.

Is a high bitrate worth it for an MKV with FLAC or TrueHD audio?

Up to a point. A lossless source gives the encoder clean material, so 192 or 256 kbps will sound as good as a phone speaker allows. Going further gains nothing you can hear on a phone: 256 kbps for 30 seconds is already about 960 KB.

I have an Android phone. Do I need M4R?

No. Android does not use M4R; ringtones there are usually MP3 or OGG files. Use MKV to MP3 with the same Trim settings, and see the M4R converter hub for every other source we can turn into an iPhone tone.

How are my files handled?

Your MKV is uploaded over an encrypted TLS connection, the audio is converted on our servers, and both the upload and the .m4r are deleted automatically after a few hours. There is no sign-up and no watermark. With a large movie file the upload is usually the slowest step, so a stable connection matters more than a fast computer.