How to convert OPUS to M4A
- Click Choose files or drop your OPUS files into the box above.
- Pick the bitrate (192 kbps by default) and, optionally, trim the start or end.
- Click Convert and download the M4A when it is ready.
OPUS vs M4A
| OPUS | M4A | |
|---|---|---|
| Compression | Lossy | Lossy |
| Typical bitrate | 32–192 kbps | 128–256 kbps AAC |
| Size | 0.25–1.4 MB per minute | 1–2 MB per minute |
| Plays on | Chrome, Firefox, Android, VLC, WhatsApp and Discord; many players and car stereos do not support it | iPhone, Mac, Android and most modern players; some older car stereos and apps prefer MP3 |
| Best for | Voice messages, calls and streaming at low bitrates | Music on Apple devices and voice memos |
About OPUS and M4A
What is OPUS?
Opus is the most efficient general-purpose audio codec available. It powers WhatsApp voice messages, Discord, Zoom and WebRTC calls, and sounds good even at very low bitrates. The downside is compatibility: many music players, car stereos and Apple apps cannot open .opus files, so they are often converted to MP3.
- Best quality at low bitrates
- Great for voice
- Royalty-free
- Many players, car stereos and editors cannot open it
What is M4A?
M4A is an MP4 file with only audio inside, usually AAC. iTunes purchases, Apple Music downloads and iPhone Voice Memos are M4A. It sounds better than MP3 at the same size, but some older devices, car stereos and upload forms accept only MP3.
- Better quality than MP3 at the same size
- Default for Apple devices and voice memos
- Some older players and forms accept only MP3
Why GlideConvert?
- Private by design. Your files are converted on your own device by your browser — they are never uploaded to a server. That keeps them private, avoids upload waits and means there is no queue.
- Fast. Images convert in a fraction of a second; video uses your device’s hardware encoder.
- Free. No sign-up, no watermark. 10 images, 5 audio files or one video at a time — Pro lifts the limits and removes ads.
Frequently asked questions
Will converting OPUS to M4A reduce quality?
M4A is a lossy format. At 192 kbps (the default) the result is practically indistinguishable from the original for most listeners; pick 256–320 kbps for the best quality, or 96–128 kbps for speech and podcasts.
Which bitrate should I choose?
128 kbps is fine for speech and podcasts, 192 kbps is great for music, and 256–320 kbps is as good as it gets. Higher bitrates mean bigger files: roughly 1 MB per minute at 128 kbps.
Are song titles, artists and cover art kept?
Yes, where M4A supports them: title, artist, album, track number and similar tags are copied from the OPUS file.
Is there a file size limit?
On the free plan each video or audio file can be up to 500 MB and each image up to 100 MB. With Pro the limit is 4 GB per file. Because everything happens on your device, the practical limit for very large files is your device’s memory.
Are my files uploaded to a server?
No. GlideConvert runs entirely in your browser: images are processed with the browser’s built-in codecs and WebAssembly, video and audio with hardware-accelerated WebCodecs (or a WebAssembly build of FFmpeg for older formats). Nothing is sent anywhere — you can even disconnect from the internet once the page has loaded.
Does it work on iPhone, Android, Mac and Windows?
Yes. It works in any up-to-date browser — Chrome, Edge, Safari, Firefox or Samsung Internet — on phones, tablets and computers, with nothing to install. On phones, extremely large images may be scaled down to fit within the browser’s memory limit; you will see a note if that happens.