MP4 to FLAC on iPhone
Convert MP4 to FLAC on your iPhone. No app to download. Open your browser, drop your file, and convert. Done in seconds.
Drop your MP4 file here or click to browse
MP4 (.mp4) · Max 20 MB
Open AudioUtils in Safari on iOS. The converter works on iPhone 8 and newer. No App Store download needed. AudioUtils uses WebAssembly to run the conversion engine locally. Your audio stays on your device.
On iPhone, converted files save to your Files app. Tap the download link and choose where to save.
MP4 is lossy. Converting to FLAC won't restore lost data, but gives you an uncompressed container for editing workflows. The output is identical regardless of which device or browser you use.
Frequently Asked Questions
Is FLAC really lossless if the MP4 audio was lossy?
FLAC's compression is lossless — meaning the decoded output is bit-identical to the input PCM. But the input PCM came from a lossy AAC decode, so the audio quality is whatever the AAC was. FLAC freezes that quality without further loss; it doesn't restore what the AAC discarded.
How big will the FLAC file be?
Roughly 4–8× the size of the source MP4's audio track. A 5-minute video with 128 kbps AAC audio (about 5 MB of audio) becomes a 25–40 MB FLAC. Compression depends on the audio content — silence and tones compress well, dense full-band music less so.
Why not just keep the MP4?
If you can play the MP4 everywhere you need to, keep it. Convert to FLAC when you need DAW/editor compatibility, archive consolidation with a lossless library, or to hand off to professionals who expect FLAC or WAV.
Will metadata transfer?
Some metadata may transfer (title, artist if present in MP4 iTunes-style atoms), but MP4's metadata schema and FLAC's Vorbis comments don't map perfectly. For critical libraries, verify and edit tags in a tool like Mp3tag or MusicBrainz Picard after conversion.
What if my MP4 has multiple audio tracks?
Only the primary audio track is extracted. Multi-track exports (e.g., dubs in different languages, commentary tracks) require ffmpeg with track mapping.
Should I convert to WAV instead of FLAC?
WAV and FLAC are both lossless. FLAC is roughly half the size, supports metadata, and is preferred for music libraries. WAV is preferred for short edits, broadcast workflows, and tools that don't read FLAC. Pick FLAC unless you have a specific WAV requirement.
About MP4
The most common video container format. Used by YouTube, smartphones, and cameras. Extract audio from any MP4 file instantly.
About FLAC
Lossless compression. Perfect quality at roughly half the size of WAV. The choice for audiophiles and archiving.