MP4 to FLAC Converter – Free Online

How to Convert MP4 to FLAC Online

Drop your MP4 file

Drag and drop your .mp4 file onto the box above, or click Choose Files. The request is already filled in: “Convert this to FLAC”.

Say how, if you want

The AI assistant uses sensible defaults. To choose the sample rate yourself, say so in the request, for example “Convert this to FLAC at 48 kHz”.

Save your FLAC file

The assistant opens with your file and converts it on your own device; the file itself is never uploaded. When the FLAC file is ready, click Save. Prefer to set everything by hand, or batch-convert several files into a ZIP? The classic converter is one click away on this page.

Why Convert MP4 to FLAC?

FLAC keeps every bit of the decoded audio yet compresses it to about half the size of WAV, which makes it the best archival format for the soundtrack of a concert recording, lecture or interview stored in MP4. Music servers such as Plex, Roon and foobar2000 handle FLAC natively.

Remember that the audio inside an MP4 is normally lossy AAC, so FLAC will faithfully preserve it but cannot add back detail that was never there. It does guarantee that no further quality is lost in future edits or conversions.

Private by design: your MP4 file is converted on your own device and never uploaded.
FLAC already asked for: the AI assistant's request says FLAC, so one drop does it. Want a particular sample rate? Just say so.
Batch friendly: the classic converter on this page takes several MP4 files in one go and downloads them as a ZIP.
Free, no watermark: no sign-up, and nothing stamped on the output.

MP4 vs FLAC

MP4 (MPEG-4 Part 14): MP4 is the most widely supported video container in the world. It usually carries H.264 or H.265 video with AAC audio, plays on every phone, browser, TV and editing app, and is the safest choice for sharing. It is best for sharing, social media, web playback and mobile devices.

FLAC (Free Lossless Audio Codec): FLAC (Free Lossless Audio Codec) compresses audio to roughly half the size of WAV without discarding a single bit, so it decodes back to the identical original. It is best for lossless music libraries and audiophile listening.

In short: keep MP4 when the priority is sharing, social media, web playback and mobile devices, and switch to FLAC when the file is headed for lossless music libraries and audiophile listening. Need a different target? The full Video Converter supports every format listed below.

MP4 to FLAC FAQ

Is MP4 to FLAC really lossless?

The FLAC output is a perfect copy of the decoded MP4 audio. The original AAC track was lossy, so think of FLAC here as 'no further loss' rather than 'studio master'.

Why not just use WAV?

FLAC gives you the same audio as WAV in roughly half the space and supports tags such as title and artist. Choose WAV only if your editing software cannot open FLAC.

Is this MP4 to FLAC converter free?

Yes. Converting MP4 to FLAC on MediaConverter.io is free, with no watermark and no sign-up. The AI assistant runs on a free daily allowance of assistant credits; the classic converter on this page has no daily limit at all.

Are my MP4 files uploaded to a server?

No. The conversion runs inside your browser using FFmpeg compiled to WebAssembly, so your .mp4 file is read and converted on your own device and never uploaded, which keeps private recordings private and means there is no waiting in an upload queue. The AI assistant only sees what you type and basic facts about the file: its name, format, duration and size.

Is there a file size limit for MP4 to FLAC?

There is no plan or account limit, but the converter loads the whole MP4 file into your browser's memory, so about 2 GB per file is the practical ceiling; larger files may fail to open. Long or high-resolution files also take longer, especially on phones.

Can I choose the FLAC settings myself?

Yes. Ask the AI assistant for a sample rate in your request. Audio track selection and every other setting are in the classic converter, one click away on this page.

Will converting MP4 to FLAC reduce quality?

FLAC is a lossless format, so it stores the audio decoded from your MP4 file without any further loss.

Which browsers support the MP4 to FLAC converter?

It is built and tested on current desktop Chrome and Edge. The conversion itself runs in WebAssembly, which every current desktop browser supports, so speed depends mostly on your computer's processor.