Step 1: Submit your MP3 files using the button above or by pull and release.
Step 2: Click the 'Transform' button to start the transformation.
Step 3: Save your converted M4R files.
MP3 to M4R Transformation FAQ
What bitrate does the M4R file use?
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A lossy M4R is encoded at 192 kbps by default. The Audio Quality setting also offers 320 kbps for the best quality and 128 kbps for a smaller file. A lossless M4R (WAV, FLAC) ignores the bitrate and keeps every sample.
Will going from MP3 to M4R reduce my audio quality?
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If MP3 is lossy and M4R is lossless (e.g. MP3 → WAV), the M4R file is no better than the MP3 — you can't recover information that's already been thrown away. If MP3 is lossless and M4R is lossy, expect the M4R codec to recompress; at 192 kbps this is transparent for most content.
Can I batch convert hundreds of MP3 files to M4R?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
Will the M4R keep the same sample rate as MP3?
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By default yes (48 kHz MP3 → 48 kHz M4R). If you need to downsample for compatibility (e.g. 96 kHz → 44.1 kHz for CD burning) the advanced sample-rate option does this with high-quality resampling.
Can I normalize loudness in the MP3 to M4R step?
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Not in this step. The converter has no loudness setting and leaves the level as it is. To even out the volume, run the finished M4R through a Normalize tool on this site.
Will the M4R play on my car stereo / iPod / Sonos?
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MP3 plays almost everywhere. AAC plays on Apple devices, most Android phones and Sonos. FLAC plays on Sonos and Android but not on older iPods, and WAV plays on nearly everything but makes large files. There are no device presets on this page, so choose the target format your player supports.
Is my MP3 file private during conversion?
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Yes. Uploaded MP3 files are processed on our own conversion servers, no person reviews them, and they are never shared. The upload and the converted M4R are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
How long does converting a 1-hour MP3 to M4R take?
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It depends on the size and length of the file. Small documents and images are usually ready quickly. Long videos take the longest, because most video conversions re-encode every frame.
Why is the M4R file louder / quieter than the MP3 source?
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The converter does not change the level: it has no gain or normalize setting. If you hear a difference, your player or media library is probably applying ReplayGain or its own volume levelling on playback; switch that off to hear the M4R as it is.
Can I convert MP3 streaming downloads to M4R?
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If the MP3 download is unprotected (no DRM), yes. DRM-encrypted streaming files (Spotify, Apple Music) are encrypted at the bit level and we can't process them. Sources from Bandcamp, SoundCloud download, and personal recordings convert fine.
