MP4 to MP3 Converter – Free Online

How to Convert MP4 to MP3 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 MP3”.

Say how, if you want

The AI assistant uses sensible defaults. To choose the bitrate, codec or sample rate yourself, say so in the request, for example “Convert this to MP3 at 320 kbps”.

Save your MP3 file

The assistant opens with your file and converts it on your own device; the file itself is never uploaded. When the MP3 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 MP3?

MP4 videos often contain music, lectures, interviews or podcasts you only need to listen to. Converting MP4 to MP3 drops the video stream entirely, leaving a small audio file you can play on any phone, car stereo or music app without wasting storage or battery on pixels you never watch.

MediaConverter.io decodes the MP4's AAC audio and re-encodes it to MP3 directly in your browser using WebAssembly. Your video never leaves your computer, and you can adjust the MP3 bitrate before converting to trade file size against quality.

Private by design: your MP4 file is converted on your own device and never uploaded.
MP3 already asked for: the AI assistant's request says MP3, so one drop does it. Want a particular bitrate, codec or 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 MP3

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.

MP3 (MPEG-1 Audio Layer III): MP3 is the universal lossy audio format. It plays on every device made in the last twenty-five years and offers small files with good quality at 192 to 320 kbps. It is best for music players, podcasts, phones and sharing.

In short: keep MP4 when the priority is sharing, social media, web playback and mobile devices, and switch to MP3 when the file is headed for music players, podcasts, phones and sharing. Need a different target? The full Video Converter supports every format listed below.

MP4 to MP3 FAQ

Does converting MP4 to MP3 reduce audio quality?

Slightly, because both AAC (inside MP4) and MP3 are lossy codecs, so the audio is decoded and re-encoded. At 192 kbps or higher the difference is inaudible to almost everyone. Ask for 192 kbps or more (or leave the classic converter's bitrate slider at 100%) to keep it that way.

Can I convert only part of an MP4 to MP3?

Convert the whole file here, then use our free Video Cut-Trim tool to keep just the section you want. Alternatively trim the MP4 first and convert the trimmed clip.

Can I convert several MP4 files to MP3 at once?

Yes. Open the classic converter on this page and drop multiple MP4 files onto its upload area; they are converted one after another and offered as a single ZIP download.

Is this MP4 to MP3 converter free?

Yes. Converting MP4 to MP3 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 MP3?

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 MP3 settings myself?

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

Which browsers support the MP4 to MP3 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.