WebM to M4R Converter

WebM to M4R: Ringtones From Browser Recordings and Web Video

WebM is the open media format Google introduced in 2010, built on a subset of Matroska. Inside a WebM you will find VP8, VP9 or AV1 video and, almost always, Opus or Vorbis audio. It is the format many browser-based screen and webcam recorders save to, the format of a lot of video clips saved from the web, and a common result of recording a WebRTC call. None of that works as an iPhone ringtone: iOS wants an .m4r, which is AAC audio in an MPEG-4 container with the extension that marks it as a tone. This converter decodes the WebM's audio, re-encodes it to AAC, writes the .m4r and drops the video. Use Trim to keep 30 seconds or less, the length Apple gives for custom ringtones.

How to Convert WebM to M4R

1. Upload Your WebM File: Drag the .webm onto the page or click "Add Files". Batch upload is supported, and the page works in mobile browsers as well as on a computer.
2. Mark the Clip with Trim: Open Advanced Options, switch Trim on, and enter a Start time and a Duration of 30 seconds or less, in seconds or HH:MM:SS.sss.
3. Set the AAC Bitrate (Optional): Audio Codec is AAC, the only codec M4R takes. Under File Compression choose Constant Bitrate (8-384 kbps), Variable Bitrate, Custom Bitrate or a target file size; set Audio Channel to Mono for a voice-only recording.
4. Convert and Download: Click Convert, download the .m4r (free, no sign-up, no watermark), copy it to your iPhone and select it in Settings > Sounds & Haptics > Ringtone.

From Opus or Vorbis to AAC: What Changes

Opus, Vorbis and AAC are all lossy codecs, so this is a decode and a fresh encode, not a lossless copy. There is no way around that: the iPhone will not use Opus or Vorbis audio as a ringtone, and the bytes have to become AAC. The practical rule is to give AAC a little more bitrate than the source had. A music clip that arrived as Opus at around 128-160 kbps comes through cleanly at 160-192 kbps AAC; a webcam or call recording that is mostly speech sounds the same at 64-96 kbps.

Opus works internally at 48 kHz, so most WebM audio decodes at 48000 Hz. Leaving Audio Sample Rate on Original keeps that rate, and 44100 Hz is equally fine for a ringtone. Neither choice adds or removes anything you will hear through a phone speaker, so there is no reason to fiddle with it unless you have a specific need.

Recordings made in a browser have one more quirk: the first second or so is often silence or a click while the recorder starts, and the end may cut off mid-word when you pressed stop. Set the Trim Start past the dead air and you avoid a ringtone that opens with nothing.

WebM vs M4R

Choosing a Bitrate for Your WebM Source

Ringtone size is bitrate in kbps times seconds, divided by 8, in kilobytes. Match the setting to what the WebM actually holds:

If you would rather name a quality band than a fixed rate, Variable Bitrate offers five AAC bands from 20k-32k up to 96k-112k; read them as nominal, since the size depends on the material. Custom Bitrate takes any value you type.

Putting the Tone on Your iPhone

• Mac: on macOS Catalina or later, connect the iPhone, select it in the Finder sidebar and drag the .m4r onto it. On a Windows PC, use iTunes. The tone then normally shows up in Settings > Sounds & Haptics > Ringtone.
• iPhone alone: save the file to Files, import it into GarageBand for iPhone and choose Share > Ringtone. Apple describes this in Create a custom ringtone on your iPhone; the audio must not be DRM-protected.
• Choose it: Settings > Sounds & Haptics > Ringtone sets it for every call; Contacts > a person > Edit > Ringtone gives just that caller the tone.

Frequently Asked Questions

Can I rename a .webm to .m4r instead of converting?

No. WebM is a Matroska-based container with Opus or Vorbis audio; M4R is an MPEG-4 file with AAC audio. Changing the extension leaves the container and the codec exactly as they were, so the iPhone will not recognise it as a tone. The audio has to be re-encoded to AAC.

Will converting Opus to AAC hurt the sound?

Slightly, in theory, because it is one lossy codec feeding another. In practice, for a 30-second clip played on a phone speaker, an AAC bitrate a notch above the source rate is indistinguishable from the WebM. Avoid repeated round trips between lossy formats, since every pass adds a little loss.

How long can the ringtone be?

Apple's support article says ringtones can be up to 30 seconds long, and its GarageBand for iPhone guide gives 30 seconds as the maximum for exported ringtones. A 40-second figure still circulates from the iTunes era, but it is not in Apple's current documentation; stick to 30 seconds.

Can I use it as a text tone as well?

Apple's GarageBand guide notes that an exported ringtone can be used as a Standard Ringtone or a Standard Text Tone. For a single contact, open Contacts, choose the person, tap Edit and set Text Tone. A short, distinctive clip of a few seconds tends to work better as a message alert than a full 30-second passage.

Is it fine to make a ringtone from a video I saved from a website?

Technically the conversion works the same, but the audio in someone else's video is usually their copyrighted work. Keeping a tone for your own phone is a different matter from sharing or selling it; only distribute audio you have the right to use.

What if I want a normal audio file, not a ringtone?

Use WebM to M4A for an AAC music file with no length concerns, or start from the M4R converter hub if your next tone comes from a different format. Android users should pick WebM to MP3, because Android ringtones are usually MP3 or OGG and do not need M4R.

How are my files handled?

Uploads travel over an encrypted TLS connection, the conversion runs on our servers, and both your WebM and the M4R are deleted automatically after a few hours. There is no sign-up and no watermark. If you need to adjust the clip afterwards, the M4R trimmer lets you pick start and end on a waveform.