How do I extract the audio from a MP4 file as FLAC?
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Upload the MP4 file and we demux the audio track, then transcode it to FLAC. There is no second video pass and no quality loss beyond what the FLAC codec itself introduces.
What audio bitrate does the FLAC file use?
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Default FLAC 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 FLAC?
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If FLAC is lossless (WAV, FLAC), every sample is preserved exactly. If FLAC is lossy (MP3, AAC, OGG, Opus), the FLAC 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 FLAC keep the original sample rate?
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By default yes — a 48 kHz audio track in MP4 becomes 48 kHz in FLAC. 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 FLAC in one batch?
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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 FLAC file be tagged with title / artist / album?
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If the MP4 container has chapter or stream metadata, we copy artist / title / album fields into the FLAC container where the FLAC format supports tags. Otherwise the FLAC file is untagged — use a tag editor (Mp3tag, Picard) post-export for richer tags.
How long does extracting FLAC from a MP4 file take?
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Audio extraction is much faster than video re-encoding — typically 5-15% of source duration. A 1-hour MP4 -> FLAC finishes in 3-9 minutes on the standard pipeline.
Can I extract just a section of the MP4 audio as FLAC?
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Not in this single tool — extract the full audio as FLAC 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?
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Yes — same privacy model as every conversion: isolated workers, automatic deletion within minutes, no human review of content. See /privacy/.
Why does my FLAC file have silent gaps?
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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 FLAC container where FLAC supports it.
Can the FLAC extraction be stereo / mono / 5.1?
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Channel layout is preserved from MP4 by default — a 5.1 MP4 produces a 5.1 FLAC 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 FLAC play on iPhone / Android / car stereo?
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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 FLAC codec most likely to play on your target.