Every day, millions of people watch recorded lectures, concert footage, podcast interviews, and music videos — but sometimes you only need the audio. Whether you want to listen to a university lecture during your morning commute, save a song from a live performance video, or create a podcast clip from a video interview, extracting audio from MP4 files is one of the most practical skills you can have.
Converting MP4 to MP3 is also incredibly useful when storage space is a concern. A 1-hour video file can easily exceed 1 GB, while the same content as an MP3 audio file might weigh in at just 50–100 MB. That's a dramatic reduction that lets you carry far more content on your phone, tablet, or laptop without running out of space.
This guide covers every method available — from quick online tools to command-line power tools — so you can pick the approach that best fits your workflow, technical comfort level, and device. By the end, you'll be able to strip audio from any MP4 file with confidence and without sacrificing quality.
At a Glance
If you're in a hurry: the fastest way to convert MP4 to MP3 is to use an online converter. Head to the MP4 to MP3 converter, upload your file, and download the audio in seconds — no software installation required.
For offline or batch conversions, VLC Media Player (free, all platforms) or FFmpeg (command line, advanced users) are excellent choices. If you're on mobile, dedicated audio extractor apps are available for both iPhone and Android.
Why Convert MP4 to MP3?
Extract Music from Videos
Concert recordings, music videos, DJ sets, and live performances are frequently shared as MP4 files. If you want to listen to the music without the video, converting to MP3 lets you play it in any music player, add it to your library, or sync it to a Bluetooth speaker — all without needing video playback capability.
Create Podcast Clips
If you record or produce podcasts as video content for YouTube, you'll eventually need clean audio-only versions for podcast platforms. Converting your MP4 recordings to MP3 is the first step in that workflow, and it can be done in bulk once you understand the process.
Save Storage Space
Video files are bulky. Even a compressed MP4 at 720p holds a massive amount of data compared to its audio equivalent. If you have a library of recorded webinars, online courses, or interviews you want to reference again, converting them to MP3 can free up gigabytes of storage without losing any of the content that actually matters to you.
Listen Offline
Streaming platforms restrict offline playback to paying subscribers, and even then, downloaded content often expires. When you extract audio from a legally owned or freely licensed video file, you create a permanent, portable audio file you can play anywhere — on a plane, in the gym, or anywhere without internet access.
Create Ringtones and Audio Clips
Short segments extracted from MP4 files make excellent ringtones, notification sounds, or audio snippets for presentations. Most phones accept MP3 files as custom ringtones, and many video editing tools can work with extracted MP3 clips more efficiently than full video files.
Understanding MP4 and MP3 Formats
Before diving into the conversion methods, it helps to understand what you're actually working with. MP4 and MP3 are fundamentally different types of files designed for different purposes.
Format Comparison
| Feature | MP4 | MP3 | |---|---|---| | Type | Container format (holds video, audio, subtitles) | Audio codec / file format | | Contains | Video + Audio + Metadata | Audio only | | Typical file size | 500 MB – 4+ GB per hour | 50–150 MB per hour | | Compression | Lossy (H.264/H.265 video, AAC audio) | Lossy (MPEG-1 Layer III) | | Audio codec inside | AAC (most common), MP3, AC-3 | MP3 (MPEG-1 Layer III) | | Device compatibility | Nearly universal (video players, browsers) | Universal (all music players, phones, cars) | | Best for | Storing and sharing video content | Music, podcasts, audiobooks, voice recordings | | Standard bitrate | 1,000–8,000 kbps (video) | 128–320 kbps |
When you "convert MP4 to MP3," you are not simply renaming a file — you are extracting the audio track from the MP4 container and re-encoding it (or copying it) into a standalone MP3 file. The video data is discarded entirely. This is why the resulting file is so much smaller.
It's also worth noting that the audio inside an MP4 file is usually encoded in AAC format, not MP3. This means the conversion process involves transcoding from AAC to MP3, which introduces a small amount of quality loss — but at 192 kbps or higher, the difference is essentially imperceptible to the human ear. For a deeper look at audio format trade-offs, see the FLAC vs MP3 comparison.
Method 1: Convert MP4 to MP3 Online (Fastest)
The online method is the best starting point for most people. It requires no downloads, no installations, and works on any operating system including Chromebooks.
Using ConvertIntoMP4's MP4 to MP3 Converter
Our MP4 to MP3 converter is designed for speed and simplicity. Here's exactly how to use it:
Step 1: Open the converter Navigate to convertintomp4.com/mp4-to-mp3 in any modern web browser. No account creation or login is required.
Step 2: Upload your MP4 file Click the upload area or drag and drop your MP4 file directly onto the page. The tool supports files up to several hundred MB depending on your browser and connection speed.
Step 3: Select your output quality Before converting, choose your desired bitrate. For most use cases, 192 kbps offers the best balance of quality and file size. If you're archiving music or need maximum fidelity, select 320 kbps.
Step 4: Click Convert The conversion happens in your browser or on our servers depending on file size. You'll see a real-time progress bar.
Step 5: Download your MP3 Once conversion completes, click the Download button. Your MP3 file will save to your default downloads folder and is ready to use immediately.
Pro Tip: If you need to convert multiple MP4 files to MP3, you can often queue several files at once using our audio converter, which supports batch uploads and various output formats beyond just MP3.
The online method works best for occasional conversions of files under 500 MB. For very large files (multi-hour recordings, for example) or high-volume batch work, one of the desktop methods below will be more efficient.
Method 2: Using VLC Media Player (Free Desktop)
VLC is one of the most widely used free media players in the world, and most people don't realize it's also a fully capable audio and video converter. It runs on Windows, macOS, and Linux.
Step-by-Step: Convert MP4 to MP3 with VLC
Step 1: Download and install VLC If you don't already have it, download VLC for free from videolan.org. It's completely free and open source with no ads or paid tiers.
Step 2: Open the Convert/Save dialog
Launch VLC. On Windows, go to Media > Convert/Save (or press Ctrl+R). On macOS, go to File > Convert/Stream.
Step 3: Add your MP4 file Click the Add button in the dialog that appears. Navigate to your MP4 file and select it, then click Convert/Save.
Step 4: Choose the MP3 output profile In the Convert window, click the dropdown under Profile and select Audio - MP3. If you don't see this option, click the wrench/edit icon next to the profile dropdown to create or modify a profile — set the codec to MP3 and choose your desired bitrate.
Step 5: Set the destination file
Click Browse next to the Destination field. Choose where you want the output MP3 saved, type a filename (make sure it ends in .mp3), and click Save.
Step 6: Click Start Click the Start button. VLC will process the file. The progress bar at the bottom of the main VLC window shows conversion progress. For long files, this may take a few minutes.
Pro Tip: VLC encodes in real-time by default, which means a 2-hour video takes roughly 2 hours to convert. To speed things up, avoid setting a very high-quality audio bitrate — the improvement is marginal but the processing time difference can be significant.
Advantages of VLC
- Completely free and open source
- No file size limits
- Works offline
- Available on all major desktop platforms
- No quality loss beyond what the bitrate settings dictate
Method 3: Using FFmpeg (Advanced / Batch Processing)
FFmpeg is the gold standard for audio and video processing. It's a command-line tool used by professional developers, content creators, and system administrators worldwide. If you're comfortable with a terminal, FFmpeg gives you complete, precise control over every aspect of the conversion.
Installation
- Windows: Download the latest build from ffmpeg.org/download.html and add it to your PATH
- macOS: Install via Homebrew with
brew install ffmpeg - Linux: Install via package manager, e.g.,
sudo apt install ffmpegon Ubuntu/Debian
Basic MP4 to MP3 Conversion
The simplest command to extract audio from an MP4 file:
ffmpeg -i input.mp4 -vn -acodec libmp3lame -ab 320k output.mp3
Let's break down what each flag does:
-i input.mp4— specifies the input file-vn— disables video recording (video is discarded)-acodec libmp3lame— uses the LAME MP3 encoder (highest quality MP3 encoder available)-ab 320k— sets the audio bitrate to 320 kbps (maximum quality)output.mp3— the name of your output file
Quality Presets
You can swap out the bitrate flag to match your use case:
# High quality (recommended for music)
ffmpeg -i input.mp4 -vn -acodec libmp3lame -ab 320k output.mp3
# Good quality (recommended for podcasts and voice)
ffmpeg -i input.mp4 -vn -acodec libmp3lame -ab 192k output.mp3
# Smaller file size (acceptable for voice-only content)
ffmpeg -i input.mp4 -vn -acodec libmp3lame -ab 128k output.mp3
# Preserve original quality (copies audio without re-encoding, fastest)
ffmpeg -i input.mp4 -vn -acodec copy output.m4a
Pro Tip: The last command (-acodec copy) doesn't actually create an MP3 — it copies the original AAC audio stream without any re-encoding, which means zero quality loss. The output file is .m4a rather than .mp3, but it plays in virtually all modern players and is the best option when you want perfect quality preservation.
Batch Conversion (Convert an Entire Folder)
To convert every MP4 file in a directory to MP3, use this shell script:
# macOS / Linux
for f in *.mp4; do ffmpeg -i "$f" -vn -acodec libmp3lame -ab 192k "${f%.mp4}.mp3"; done
# Windows Command Prompt
for %f in (*.mp4) do ffmpeg -i "%f" -vn -acodec libmp3lame -ab 192k "%~nf.mp3"
This is invaluable when you have dozens of lecture recordings or interview files to process at once.
Extract Audio from a Specific Time Range
If you only want a clip from a larger video, FFmpeg can extract just that portion:
ffmpeg -i input.mp4 -ss 00:01:30 -to 00:04:00 -vn -acodec libmp3lame -ab 192k clip.mp3
-ss 00:01:30— start at 1 minute 30 seconds-to 00:04:00— stop at 4 minutes
This approach is much faster than converting the entire file and trimming afterward.
Method 4: Converting MP4 to MP3 on iPhone and Android
Mobile users aren't left behind — there are solid options for extracting audio directly on your phone without needing a computer.
On iPhone (iOS)
Using Documents by Readdle + an Online Converter: The simplest method on iPhone is to open our MP4 to MP3 converter in Safari, upload your MP4 (select it from the Files app), and download the resulting MP3 directly to your device.
Using the Shortcuts App: iOS's built-in Shortcuts app can automate audio extraction. Search the Shortcuts Gallery for "Extract Audio" shortcuts that accept a video as input and output an audio file.
Using a Dedicated App: Apps like "Video to MP3 Converter" or "Media Converter" (both available on the App Store) let you import a video from your camera roll or Files app and export the audio as MP3.
On Android
Android has more flexibility due to its open file system. Several excellent free apps are available:
- MP3 Video Converter (Springwalk): Simple, fast, supports various output bitrates
- VidCompact: Converts video to audio with bitrate and format controls
- Video to MP3 Converter (InShot): Clean interface, supports MP3 and M4A output
General steps on Android:
- Install a video-to-audio converter from the Play Store
- Open the app and grant media permissions
- Browse to your MP4 file and select it
- Choose MP3 as the output format and set your preferred bitrate
- Tap Convert and wait for processing to complete
- The MP3 file will be saved to your device storage, usually in a dedicated output folder
Pro Tip: If your MP4 file is already in your Google Drive or Dropbox, many Android converter apps can connect directly to cloud storage — you won't need to download the video to your device first.
Choosing the Right Audio Quality (Bitrate Guide)
Bitrate is the single most important setting when converting MP4 to MP3. It determines how much audio data is preserved per second, directly affecting both sound quality and file size. Understanding bitrates helps you make the right trade-off for each situation.
MP3 Bitrate Comparison Table
| Bitrate | File Size (1 hr) | Quality Level | Best Use Case | |---|---|---|---| | 64 kbps | ~28 MB | Poor — audible artifacts, thin sound | Voice memos, quick notes (not recommended for music) | | 128 kbps | ~56 MB | Acceptable — most listeners won't notice flaws in quiet environments | Spoken word podcasts, audiobooks, casual listening | | 192 kbps | ~84 MB | Good — transparent for most listeners, minimal artifacts | Podcasts, streaming, everyday music listening | | 256 kbps | ~112 MB | Very good — virtually indistinguishable from original for most people | Music archiving, high-quality playback | | 320 kbps | ~140 MB | Excellent — maximum MP3 quality, imperceptible difference | Music production, audiophile listening, archiving |
Which Bitrate Should You Choose?
For spoken word content (lectures, interviews, podcasts, audiobooks), 128 kbps is perfectly adequate. The human voice doesn't require the high-frequency detail that music does, so the extra data in higher bitrates is largely wasted.
For music, go with 192 kbps as your minimum. If you're creating a music library you intend to keep long-term, 320 kbps is the safe choice — storage is cheap, and you'll never wish you'd encoded it better.
For archiving important content, always encode at the highest quality you can tolerate. You can always re-encode to a lower bitrate later, but you cannot recover detail that was discarded during the original conversion.
If audio quality is a top priority and you're not bound to MP3 specifically, see our guide on best audio format for podcasts for a broader look at alternatives like AAC, OGG, and FLAC.
Tips for Best Audio Quality
Getting the best possible audio from your MP4 conversion isn't just about picking the right bitrate. These additional tips will help you maximize quality across every step of the process.
Start with the best source quality available. If you have access to multiple copies of the same video at different resolutions or bitrates, convert from the highest quality version. A 4K video with a high-bitrate audio track will yield a better MP3 than a 360p version of the same content.
Avoid re-encoding multiple times. Every time an audio file is re-encoded from one lossy format to another (such as AAC to MP3, or MP3 to AAC), you lose a small amount of quality. If possible, go directly from your original source to your final output format without intermediate conversions.
Match or exceed the original audio bitrate. If the audio track inside your MP4 was encoded at 128 kbps AAC, setting your MP3 output to 320 kbps won't give you better quality than the source — it will just produce a larger file. Use the bitrate that matches your source as a rough ceiling.
Normalize audio volume after conversion. Many videos have inconsistent audio levels. After extracting to MP3, you can use a free tool like Audacity or FFmpeg's loudnorm filter to bring the volume up to a consistent level — this is especially useful for podcast clips and lecture recordings.
Pro Tip: FFmpeg's loudnorm filter can normalize audio to broadcast standards in a single command:
ffmpeg -i input.mp3 -af loudnorm=I=-16:LRA=11:TP=-1.5 output_normalized.mp3
This applies EBU R128 loudness normalization — the same standard used by Spotify, Apple Podcasts, and YouTube.
Check the audio before finalizing. Always play the first and last 30 seconds of your converted MP3 to verify there are no sync issues, silence, or corruption. It's far better to catch a failed conversion immediately than to discover it later when you need the file.
Frequently Asked Questions
Does converting MP4 to MP3 lose quality?
Technically, yes — but in practice, the loss is often imperceptible. The audio inside an MP4 file is typically encoded in AAC format. When you convert to MP3, you're transcoding from one lossy format to another, which introduces a small additional loss. At 192 kbps or above, the difference is essentially inaudible to the vast majority of listeners. The only scenario where quality loss becomes obvious is if you're converting a low-bitrate source (e.g., 96 kbps AAC) to an even lower MP3 bitrate, or if you're doing multiple rounds of re-encoding.
What bitrate should I use for my MP3?
For spoken word content like lectures, interviews, and podcasts, 128 kbps is the sweet spot — it's small and perfectly clear. For music, use at least 192 kbps, and for archiving or audiophile listening, choose 320 kbps. There's no benefit to going higher than the source bitrate; if your MP4's audio track was recorded at 128 kbps AAC, encoding the MP3 at 320 kbps won't recover any additional detail.
Can I extract just a portion of the audio?
Yes. With FFmpeg, you can specify a start time and end time to extract only the segment you need:
ffmpeg -i input.mp4 -ss 00:02:00 -to 00:05:30 -vn -acodec libmp3lame -ab 192k clip.mp3
Most online converters don't offer trimming built into the conversion step, but you can always extract the full audio first and then trim it using a free tool like Audacity or an online audio editor.
Why is my converted MP3 file so large?
There are two common reasons. First, you may have set an unnecessarily high bitrate (e.g., 320 kbps for a voice recording that only needs 128 kbps). Second, the original MP4 may have been very long. A 3-hour video at 320 kbps produces an MP3 roughly 420 MB in size — which is large but technically correct. If file size is a concern, lower the bitrate or trim the audio to only the portions you need.
Is it legal to convert MP4 to MP3?
The legality depends entirely on the content and how you intend to use the resulting MP3. Converting a video you recorded yourself, a video you purchased and own, or a video under a Creative Commons or public domain license is perfectly legal. Downloading or converting copyrighted music videos, movies, or TV shows from streaming platforms without authorization is generally a violation of copyright law and those platforms' terms of service. Always ensure you have the rights or permission to convert and use any content.
What's the difference between MP3 and AAC?
Both are lossy audio codecs, but AAC (Advanced Audio Coding) is technically superior — it achieves better sound quality at the same bitrate, and is the default audio format inside MP4 files. MP3 is older but has near-universal compatibility, including in older car stereos, basic Bluetooth speakers, and legacy devices. If your target playback device supports AAC (which most modern devices do), you might consider saving the audio as .m4a (AAC) rather than converting to MP3 — you'll get better quality at a smaller file size. For a broader comparison of audio codec options, check out our FLAC vs MP3 comparison guide.
Can I convert MP4 to formats other than MP3?
Absolutely. MP3 is the most universally compatible audio format, but depending on your use case, other formats may serve you better. WAV and FLAC offer lossless quality for professional audio work. AAC (M4A) gives better quality than MP3 at equivalent bitrates. OGG Vorbis is an excellent open-source alternative. Our audio converter supports conversion to all of these formats from MP4 and other video sources.
Conclusion
Converting MP4 to MP3 is one of those everyday digital tasks that sounds technical but is actually straightforward once you know your options. Whether you're saving a lecture for your commute, extracting the audio from a concert video, or building a podcast from video interviews, the right tool for the job depends on your situation.
For quick, one-off conversions on any device, the MP4 to MP3 converter is your fastest path — no downloads, no setup, just upload and go. For desktop users who process files regularly, VLC provides a friendly graphical interface without any cost. And for developers, power users, or anyone handling dozens of files at once, FFmpeg offers unmatched control and speed through the command line.
Remember: always encode at a bitrate appropriate to your content and audience. A podcast clip doesn't need 320 kbps, and a music archive shouldn't be squeezed into 96 kbps. Match your quality settings to your use case, and you'll end up with clean, compact MP3 files that sound exactly as they should.
Ready to get started? Head to the MP4 to MP3 converter and extract your first audio file in under a minute. And if you want to explore more about video and audio formats, take a look at our guides on MP4 vs MOV, how to convert MOV to MP4, and the best audio format for podcasts.
For a complete overview of everything our platform supports, visit the MP3 converter hub for MP3-specific tools and the MP4 converter hub for all things MP4 — or explore the full video converter to see every format we handle.
