How to Convert MP4 to MP3 Online for Free — Extract Audio from Any Video
You have a video — a podcast recorded as MP4, a music video, an online lecture, a recorded meeting, a voice memo captured as video. You need just the audio. Converting MP4 to MP3 is one of the simplest file operations there is, and you can do it in seconds without downloading any software.
How to Convert MP4 to MP3 Online for Free
The fastest method works in any browser on any device — Windows, Mac, iPhone, or Android.
Step 1: Go to iFormat.io MP4 to MP3 converter.
Step 2: Click Choose File or drag and drop your MP4 video into the upload area.
Step 3: Select MP3 as the output format (it's the default).
Step 4: Click Convert and wait a few seconds.
Step 5: Click Download to save your MP3 file.
Supported Input Formats
You can convert more than just MP4. The converter also accepts: MOV (iPhone videos), AVI, WebM, MKV, M4V, and most other common video formats.
What Actually Happens When You Convert MP4 to MP3?
An MP4 file is a container — it holds both a video track and an audio track packaged together. When you convert to MP3, the tool simply extracts the audio track and discards the video. No re-encoding of the video happens; it's just removed.
Important: the audio quality in your MP3 cannot be better than the audio quality in the original MP4. If the video was recorded at 128 kbps audio, your MP3 will be 128 kbps quality at best, regardless of what settings you use. Conversion doesn't add quality — it only extracts what's already there.
How to Convert MP4 to MP3 on Windows (Without Software)
If you have VLC Media Player installed (it's free and very widely used), you already have everything you need:
1. Open VLC → Media → Convert / Save (Ctrl+R).
2. Click Add and select your MP4 file.
3. Click Convert / Save at the bottom.
4. Under Profile, select Audio - MP3.
5. Choose a destination file name (ending in .mp3).
6. Click Start.
VLC processes the file and saves the MP3 to your chosen location. This works completely offline with no file size limits.
How to Convert MP4 to MP3 on a Mac
QuickTime Player (built into every Mac) can export audio from videos, though it saves as M4A (not MP3). To export audio in QuickTime: File → Export As → Audio Only. This gives you an M4A file, which plays on all Apple devices and most modern audio players.
If you specifically need MP3 (for older devices, car stereos, or specific players that don't accept M4A), use the online converter or VLC (which is available for Mac too, at videolan.org).
How to Convert MP4 to MP3 on iPhone or Android
Mobile conversion is easiest via browser — no app to install. On your iPhone or Android phone:
1. Open Safari (iPhone) or Chrome (Android).
2. Go to iformat.io/mp4-to-mp3.
3. Tap Choose File and select your video from your camera roll or Files app.
4. Tap Convert, then Download.
5. The MP3 saves to your Downloads folder or Files app.
MP3 vs M4A vs AAC — Which Audio Format Should You Use?
Once you have the audio extracted, you might want to choose a format other than MP3. Here's when each makes sense:
MP3 — Universal compatibility. Plays on every device ever made, including old car stereos, budget Bluetooth speakers, and ancient Windows Media Player. Slightly lower quality than M4A at the same file size. Use this when compatibility matters more than audio quality.
M4A / AAC — Better quality than MP3 at the same bitrate. Native format for Apple devices. Works in modern players and browsers. Use this for music you'll listen to on Apple devices or modern systems.
WAV — Uncompressed, lossless audio. Largest file size by far. Use this for professional audio editing or archiving where quality is everything.
FLAC — Lossless compression. Smaller than WAV, same quality. Use this for high-quality music archiving.
Quick Format Guide
Universal compatibility: MP3
Apple devices / modern players: M4A (AAC)
Professional editing: WAV
Lossless archive: FLAC
Common Mistakes When Converting MP4 to MP3
Expecting better audio quality after conversion
If the original video has muffled, low-quality audio, your MP3 will too. Conversion extracts the existing audio — it can't improve it.
Getting a very large MP3 file
Check your bitrate setting. A 320 kbps MP3 is studio quality but large. For spoken word (podcasts, lectures, meetings), 128 kbps is more than sufficient and roughly a quarter the file size.
The converted MP3 is completely silent
Some video files have no audio track — screen recordings in some apps, or video files that have had their audio stripped. Check the original video has sound before converting.
Converting a music video to MP3 and getting copyright claims
Downloading and converting YouTube videos to MP3 may violate YouTube's terms of service and copyright law. Only convert videos you own or have rights to.
Extract Audio from Other Video Formats
The same online tool handles other video formats too — not just MP4. You can extract audio from:
• MOV — iPhone videos and Mac screen recordings
• MKV — downloaded movies and TV shows
• AVI — older video files from cameras and camcorders
• WebM — web-based video files
• WMV — Windows Media Video files
If you need to convert audio between formats (MP3 → WAV, M4A → MP3, etc.), use the audio converter which handles 20+ audio format combinations.
Convert MP4 to MP3 — Free, Instant
Upload your MP4 video and download an MP3 audio file in seconds. No account required.