How do I extract the audio from a MP4 file as M4R?
+
Upload the MP4 file and we demux the audio track, then transcode it to M4R. There is no second video pass and no quality loss beyond what the M4R codec itself introduces.
What audio bitrate does the M4R file use?
+
Default M4R bitrate is 192 kbps (transparent for music). You can override to 320 kbps (audiophile) or 96-128 kbps (voice / podcast / smaller file). The choice is exposed in the advanced options before extraction.
Will I lose audio quality going from MP4 to M4R?
+
If M4R is lossless (WAV, FLAC), every sample is preserved exactly. If M4R is lossy (MP3, AAC, OGG, Opus), the M4R codec recompresses — at 192 kbps this is transparent for almost all content. Recovering quality that was already gone in the MP4 source is impossible.
Does the extracted M4R keep the original sample rate?
+
By default yes — a 48 kHz audio track in MP4 becomes 48 kHz in M4R. If you need 44.1 kHz (CD-quality) for compatibility with older players, the advanced options expose a sample-rate dropdown that resamples with a high-quality filter.
Can I extract audio from multiple MP4 files to M4R in one batch?
+
Yes — drop a folder of MP4 files in and we extract audio in parallel. Pro users get more parallel workers; on a 50-file batch this is the difference between 90 seconds and 8 minutes.
Will the M4R file be tagged with title / artist / album?
+
If the MP4 container has chapter or stream metadata, we copy artist / title / album fields into the M4R container where the M4R format supports tags. Otherwise the M4R file is untagged — use a tag editor (Mp3tag, Picard) post-export for richer tags.
How long does extracting M4R from a MP4 file take?
+
Audio extraction is much faster than video re-encoding — typically 5-15% of source duration. A 1-hour MP4 -> M4R finishes in 3-9 minutes on the standard pipeline.
Can I extract just a section of the MP4 audio as M4R?
+
Not in this single tool — extract the full audio as M4R here, then use /audio-trim/ or /audio-cutter/ to clip the section. The two-step path is faster than a combined operation because we avoid re-decoding the whole file twice.
Is my MP4 file private during audio extraction?
+
Yes — same privacy model as every conversion: isolated workers, automatic deletion within minutes, no human review of content. See /privacy/.
Why does my M4R file have silent gaps?
+
Silent gaps usually mean the MP4 file had a multi-track audio layout and we picked the wrong stream. Use the "audio stream" option to explicitly pick stream 0, 1, etc., or re-mux all streams to a multi-track M4R container where M4R supports it.
Can the M4R extraction be stereo / mono / 5.1?
+
Channel layout is preserved from MP4 by default — a 5.1 MP4 produces a 5.1 M4R where the codec supports it (AAC, FLAC, OGG, Opus). You can force stereo or mono via the channel-downmix option, which is useful for podcast workflow.
Does the extracted M4R play on iPhone / Android / car stereo?
+
MP3 plays everywhere. AAC / M4A plays on Apple and most Android. OGG / Opus needs a recent player on iOS. Advanced options expose a "device" preset that picks the M4R codec most likely to play on your target.