Step 1: Supply your MP4 files using the button above or by haul and lay.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Get your converted FLAC files.
MP4 to FLAC Conversion FAQ
How do I extract the audio from a MP4 as FLAC?
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Upload the MP4 file and the converter demuxes the audio track, then re-encodes it as FLAC. No re-encoding of the video happens — only the audio stream is processed, which keeps it fast even on long videos.
Will the audio quality match the original MP4 track?
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Yes — the audio is extracted at the source bitrate where possible. If you pick a higher FLAC bitrate than the source, the file will not improve in quality, just grow in size.
Is the MP4 to FLAC conversion reversible?
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You can convert the FLAC back to MP4 on this site. If either format involved is lossy, the round-trip is not bit-perfect even though it is visually or audibly close.
Will the FLAC be larger than the MP4?
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Yes — lossless containers store every byte. Expect the FLAC to be 3-8x the size of the MP4. The benefit is no further quality loss on editing or re-encoding.
Does converting MP4 to FLAC improve the audio quality?
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No, and it is worth being blunt: nothing can. The MP4 already discarded detail during its original encode, and wrapping what remains in a lossless FLAC preserves exactly that — no more. The file gets several times larger and sounds identical. It is still the right move before editing, because FLAC will not add a second generation of artefacts when you export. FLAC gives you WAV fidelity at half the size, with proper metadata tags and embedded artwork, which is why it dominates lossless music libraries. MP4 only supports one widely-honoured subtitle format (mov_text), and multi-track audio is unreliable outside desktop players.
Can I tag the FLAC with artist and album information?
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Yes, and it is a genuine gain over MP4, which has nowhere dependable to store any of it. FLAC carries title, artist, album, year, track number and embedded cover art in the container itself, so a music library files it correctly without a manual pass.
Will the FLAC play in my car or on older hardware?
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Often not. MP4 is decoded by essentially everything, including car head units and elderly players; FLAC needs software that knows the codec, which standalone hardware frequently does not have. If the destination is a car stereo or a portable player, that is a strong argument for staying on MP4. FLAC is still several times larger than a good lossy file, and Apple’s ecosystem only added support recently and grudgingly.
Is there a file-size limit when converting MP4 to FLAC?
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Anonymous uploads are capped at a generous default; signed-in free accounts get a higher cap, and Pro accounts have no per-file limit. Browser memory is usually the practical constraint long before our server-side limits kick in.
Can I batch-convert several MP4 files to FLAC at once?
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Yes. Drop or pick multiple MP4 files in one upload — the converter processes them in parallel and returns a ZIP of the FLAC results. There is no need to repeat the upload step per file.
What happens to my MP4 files after the conversion?
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Uploaded files and FLAC outputs are auto-deleted after a short retention window. We do not inspect, share, or train on user files. Direct download links are time-limited and tied to your session.
What apps can play a FLAC file?
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FLAC plays in most music players, browsers, and media libraries. iTunes / Apple Music, VLC, Foobar2000, and phone media apps handle it natively.
Do I need to install software to convert MP4 to FLAC?
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No. The converter runs entirely in your browser plus our cloud — no plugin, no install, no admin rights. It works on Windows, macOS, Linux, ChromeOS, iOS, and Android.
