File Convert

Convert M4B to OPUS

Free online M4B-to-OPUS converter — upload a M4B file and download a OPUS. Fast, private, no signup.

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M4B vs OPUS

M4B

MPEG-4 audiobook (AAC, with chapter support).

About M4B ↗

OPUS

Modern low-latency lossy audio codec.

About OPUS ↗

M4B to OPUS: frequently asked questions

How do I convert M4B to OPUS?

Drop your M4B file into the converter above — we auto-detect the real format from its bytes, convert it, and give you a OPUS to download. No software to install.

Is the M4B to OPUS converter free?

Yes. Convert M4B to OPUS for free right in your browser, with no account needed to get started.

Is it safe and private?

Your file is transferred over an encrypted connection and anonymous uploads are temporary. You can also view and strip metadata (location, device, author) before you download.

What's the difference between M4B and OPUS?

MPEG-4 audiobook (AAC, with chapter support). Modern low-latency lossy audio codec.

Related conversions

Convert M4B to: MP3 · WAV · FLAC · M4A · AAC · AC3 · AIFF · M4R · OGG · WV

Convert to OPUS from: AAC · AC3 · AIFF · AMR · APE · FLAC · M4A · M4R · MP3 · OGG

Browse all supported formats →