Reset to defaults
Need help?ASF to M4R: Ringtones from Windows Media Recordings
ASF, the Advanced Systems Format (originally Advanced Streaming Format), is Microsoft's container for Windows Media. A .wmv and a .wma are ASF files with a more specific extension; files that keep the plain .asf name usually come from software that wrote the container directly, such as Windows Media Encoder captures, saved Windows Media streams, and some network cameras and DVR systems. The audio inside is usually Windows Media Audio, although the container can hold other codecs.
This page takes the audio stream from the ASF file, decodes it and encodes it as AAC in an .m4r file: AAC-LC in an MPEG-4 container, the format iPhone uses for custom ringtones. Any video is ignored. Apple says ringtones can be up to 30 seconds long, so use Trim to pick the half-minute you want.
How to Convert ASF to an iPhone Ringtone
- Upload the ASF File: Drag the
.asffile onto the page or click "Add Files". You can queue several and convert them with the same settings. - Trim to 30 Seconds or Less: Switch Trim from Unchanged to Trim, enter the Start time (seconds or HH:MM:SS.sss) and a Duration of 30 seconds or less.
- Choose Bitrate and Channels: AAC is the only codec M4R takes. Under File Compression, Constant Bitrate (8-384 kbps) gives a predictable size; Variable Bitrate, Quality Preset, Custom Bitrate and a target file size are also offered. Pick Mono for speech or Stereo for music.
- Convert and Install: Click Convert, download the
.m4r, copy it to the iPhone and select it in Settings > Sounds & Haptics > Ringtone.
One Container, Three Extensions
| Extension | What it usually signals | Make a ringtone with |
|---|---|---|
.asf |
ASF file with any mix of streams, often from encoders, stream captures or cameras | This page |
.wmv |
ASF with Windows Media Video, usually with WMA audio | WMV to M4R |
.wma |
ASF with audio only | WMA to M4R |
All three are the same container underneath. Use the page that matches your file's extension.
ASF vs M4R
| Property | ASF | M4R |
|---|---|---|
| Owner | Microsoft, proprietary container | MPEG-4 file format with AAC audio |
| Typical audio | Windows Media Audio; occasionally other codecs | AAC-LC only |
| Video | Often Windows Media Video, sometimes none | None |
| Metadata | Fields in the ASF Header object | MPEG-4 metadata |
| Rights protection | Possible (Windows Media DRM) | None |
| iPhone support | Needs conversion | Native, as a ringtone or text tone |
| Size of 30 seconds | Depends on the recording | About 480 KB at 128 kbps |
Before You Convert: Three Quick Checks
- Is there an audio track? Some security-camera and screen-capture ASF files contain no sound. Open the file in VLC and look at Audio > Audio Track. If nothing is listed, there is no audio to make a ringtone from.
- Is it DRM-protected? Windows Media DRM encrypts the streams, and a protected file cannot be decoded here. Your own recordings are normally unprotected.
- Where is the moment? Note the elapsed time in a player, then use it as the Trim Start time. Starting a fraction of a second early keeps the first word or beat intact.
Choosing a Bitrate for Re-encoded Windows Media Audio
| Source material | Constant Bitrate | Audio Channel |
|---|---|---|
| Music, WMA at 128 kbps or more | 128-192 kbps | Stereo |
| Music, low-rate WMA (64 kbps or less) | 96-128 kbps | Stereo |
| A voice, a laugh or a single sound | 64-96 kbps | Mono |
| Camera or stream audio of unknown quality | 128 kbps | Mono or Original |
WMA is lossy, so encoding to AAC is a second lossy pass. Matching or slightly exceeding the source rate keeps that pass inaudible; going far above it only enlarges the file. At kbps x seconds / 8 = kilobytes, every row gives a ringtone under a megabyte.
Installing the Ringtone
Connect the iPhone to a Mac with macOS Catalina or later, select it in the Finder sidebar and drag the .m4r onto it, or add it with iTunes on Windows. With only the phone, save the file to Files, import it into GarageBand and use Share > Ringtone. Then pick it in Settings > Sounds & Haptics > Ringtone, or assign it to one caller in Contacts > Edit > Ringtone. On Android, use ASF to MP3 instead, since Android ringtones are usually MP3 or OGG.
Frequently Asked Questions
Is ASF the same as WMV?
They share the same container. Microsoft defines ASF as the format for Windows Media Audio and Video; .wmv and .wma mark ASF files holding video or audio-only content, and a plain .asf can hold either. This page reads the audio stream and ignores any video.
Why did my ASF file fail to convert?
The two usual reasons are that the file has no audio stream, which is common with some camera and screen recordings, or that it is DRM-protected. Confirm in a media player that the file plays with sound before converting.
Will converting WMA to AAC hurt the quality?
Only slightly, and not audibly on a phone at sensible bitrates. Both codecs are lossy, so the AAC encode cannot restore what WMA discarded, but at or above the source bitrate the second pass is transparent for a 30-second clip.
How long can an iPhone ringtone be?
Apple says up to 30 seconds, and GarageBand shortens a longer ringtone automatically when you export it. A 40-second limit is quoted from the iTunes era, but it is not in Apple's current documentation.
Is the M4R different from an M4A file?
Only in its extension. Both are AAC-LC in an MPEG-4 container, written here by the same muxer, and the .m4r name tells iOS to treat the file as a tone. For a full-length music file, use ASF to M4A.
Can I give the tone to just one contact?
Yes. After the tone is on the iPhone, open Contacts, choose the person, tap Edit, then Ringtone or Text Tone, and select it from the list.
What happens to my ASF file?
It is uploaded over an encrypted (TLS) connection, processed on our servers and deleted automatically after a few hours, together with the ringtone. No sign-up, no watermark, and the converter is free.