M4B → MP2
Convert M4B audio to MP2 entirely in your browser — no upload, no watermark, no sign-up.
Drop files here
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images · audio · video · documents · archives · Free: 200 MB per file · Pro: 5 GB
Your first conversion lands here automatically — saved on this device only, never uploaded.
100% Private
Runs in your browser. No upload.
Instant
No queue, no server roundtrip.
Offline-ready
Works after first load.
Moving M4B audio to MP2 is about compatibility and size — which players accept the file and how much disk or bandwidth it costs once it gets there. MP2 (MPEG-1 Audio Layer II) earns its place here: broadcast-grade robustness and near-universal decoder support. M4B is an MP4 audio file flagged as an audiobook, so players remember your position and honour chapter marks. Apple Books and most audiobook apps expect it.
M4B is an MP4 audio file flagged as an audiobook, so players remember your position and honour chapter marks. Apple Books and most audiobook apps expect it.
The audio is decoded and re-encoded, so the running time, channels and sample content stay intact while bitrate and file size follow MP2. Going from a compressed M4B file to any other lossy format is a second generation of compression — start from the highest-quality source you have when it matters, and expect a lossless target to grow the file rather than improve the sound.
What you gain with MP2: Broadcast-grade robustness and near-universal decoder support.
Drop your M4B file above and Morphio decodes it locally, then re-encodes it as MP2 using WebAssembly + the browser's native codecs. Nothing is ever uploaded — your files stay on your device. Free supports batches of 5 files; Pro supports batches of 250, subject to your device's memory. See exactly how in-browser conversion works.
Open the M4B to MP2 page, drop your audio file on the drop zone and press convert. Morphio runs an FFmpeg build compiled to WebAssembly that runs inside the page, so the M4B data never leaves your device and no server ever receives a copy.
Sample rate and channel layout carry across, and you keep the original file untouched on disk. Converting M4B to MP2 only rewrites the container and encoding you asked for — the source file on your disk is never modified.
Yes. The free plan covers 10 conversions a day with files up to 200 MB and adds no watermark or sign-up. Morphio Pro ($5/month, or $29 once for lifetime access) removes the daily cap and raises the per-file limit to 5 GB.
Morphio decodes the M4B file at full fidelity and re-encodes it at a high-quality MP2 setting, so the difference is normally invisible or inaudible. What conversion cannot do is recover detail the original M4B file already threw away.
Yes — Free supports batches of 5 files and 10 conversions per day; Pro supports batches of 250 with no daily conversion cap. Your device's memory can impose a lower practical limit. Only usage counts reach the server, never files.
No. The conversion runs entirely inside your browser, so the file never leaves your device. The page and the required decoder must load first; free usage-limit checks may require a connection.