🔒 Local conversion, nothing is uploaded

Convert OPUS to M4A online

Free, no sign-up, no limits. Drop your OPUS files, get M4A files back in seconds.

1 files converted so far

Drop your OPUS files here

or · multiple files accepted

Local conversion: your files never leave your device.

Why convert OPUS to M4A?

You received a WhatsApp, Telegram or Discord voice message (.opus/.ogg) and it will not open on your computer, car stereo or editing software. M4A solves the problem.

How to do it, step by step

  1. Drop your OPUS fileinto the area at the top of the page (or several files at once). On mobile, tap the area and pick the file from your apps.
  2. Check the output format: M4A is already selected. For music, 192 kbps is transparent for most listeners and 320 kbps gives the maximum. For voice (memos, podcasts, lectures), 128 kbps is more than enough and halves the file size.
  3. Start the conversion.The FFmpeg engine loads once (≈ 10 MB), then each file is processed in a few seconds without leaving your device.
  4. Download your M4A, directly or as a .zip if you converted several files. The name and metadata (title, artist, cover art) are preserved.

The OPUS format (Opus Interactive Audio Codec)

Opus is currently the most efficient audio codec: it delivers the best possible quality at very low bitrates. It is the format of WhatsApp, Telegram and Discord voice messages and of video calls. Excellent, but still poorly recognized by consumer players and car stereos.

  • Exceptional quality at low bitrates
  • Free format
  • The standard for voice on the internet
  • Very few devices play it
  • Often impossible to open on Windows without extra software

The M4A format (MPEG-4 Audio)

M4A is Apple's audio container, used by iTunes, Apple Music, iPhone voice memos and Mac recordings. It usually holds AAC audio, sometimes ALAC (lossless). Very good quality at a small size, but poorly supported by some car stereos, MP3 players, Windows software and websites.

  • Excellent quality at the same bitrate
  • Native Apple format (iPhone, Mac, iTunes)
  • Can hold lossless audio (ALAC)
  • Limited compatibility outside the Apple ecosystem
  • Rejected by many car stereos and older devices
  • Less universal than MP3

OPUS vs M4A comparison

OPUSM4A
CompressionLossyLossy
Typical size (1 min, music)≈ 0.7 MB≈ 1.2 MB (160k)
Common useWhatsApp/Telegram voice messages, Discord, callsiPhone voice memos, iTunes purchases, GarageBand recordings, Mac Voice Memos
Metadata (title, cover art)YesYes

Frequently asked questions

Does converting OPUS to M4A lose quality?

M4A is a lossy compressed format: a conversion always involves re-encoding. At 192 kbps or higher, the difference is inaudible in the vast majority of cases. Just avoid chaining several successive conversions.

Is the OPUS to M4A converter free?

Yes, with no limit on the number of files, no sign-up and no watermark. Each file can be up to 200 MB.

Are my OPUS files uploaded to the internet?

No. The OPUS to M4A conversion is performed by FFmpeg directly in your browser (WebAssembly). Your files never leave your computer or phone.

How do I convert OPUS to M4A on iPhone or Android?

Open this page in Safari or Chrome, tap the drop area, select your OPUS file (from Files, Voice Memos, Downloads or WhatsApp), then tap "Convert". The M4A downloads to your files.

Can I convert several OPUS files at once?

Yes, add all your files in one go. They are converted one after another and a button lets you download everything as a .zip archive.

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