You have a video file. You only need the audio. Maybe it’s a lecture, a podcast episode someone uploaded to YouTube, a music track from a screen recording, or a voice memo that ended up as MP4 for some reason.
I’ve been doing this conversion for years across dozens of tools, and honestly most of them work fine for simple jobs. The differences show up when you need batch conversion, specific bitrate control, or you’re working with files over 500 MB. I tested 8 tools specifically for this guide – uploading the same 47-minute MP4 file (a conference talk, 1.2 GB) to each one and comparing output quality, speed, and any catches in the free tier.
If you’re working with other file formats too, check out our guide on best free audio converters for a broader look at audio conversion tools.
Quick Comparison Table
| Tool | Type | Max Free File Size | Batch Convert | Max Bitrate | Best For |
|---|---|---|---|---|---|
| VLC Media Player | Desktop | Unlimited | Yes | 320 kbps | Power users, large files |
| FFmpeg | CLI | Unlimited | Yes (scripted) | 320 kbps | Developers, automation |
| CloudConvert | Online | 1 GB | Yes (5 files) | 320 kbps | Quick one-off conversions |
| FreeConvert | Online | 1 GB | Yes (5 files) | 320 kbps | Simple browser-based conversion |
| HandBrake | Desktop | Unlimited | Yes (queue) | 320 kbps | Video editors who also need audio |
| Zamzar | Online | 25 MB (free) | No | 256 kbps | Tiny files, no signup needed |
| Any Video Converter | Desktop | Unlimited | Yes | 320 kbps | Windows users wanting a GUI |
| Online Audio Converter (123apps) | Online | 2 GB | Yes | 320 kbps | Largest free file size limit |
1. VLC Media Player – Best Free Desktop Option
VLC is primarily a media player, but it has a surprisingly capable converter built in. Most people don’t know about it because the feature is buried under Media > Convert/Save.
How to convert MP4 to MP3 with VLC:
- Open VLC, go to Media > Convert/Save (or press Ctrl+R)
- Click Add, select your MP4 file
- Click Convert/Save at the bottom
- Under Profile, select Audio – MP3
- Choose destination file and click Start
The conversion speed depends on your hardware, but on my test machine (Ryzen 5 5600X, 16 GB RAM), the 1.2 GB conference talk converted in about 90 seconds. Quality was identical to the source audio at 320 kbps.
Pros:
- Completely free, no ads, open source
- No file size limits whatsoever
- Works on Windows, Mac, Linux
- Batch conversion possible through the playlist method
Cons:
- Interface for conversion is clunky and unintuitive
- No drag-and-drop for the converter
- Batch conversion requires a workaround (add files to playlist, then convert)
Platform: Windows, macOS, Linux | Price: Free (open source, GPLv2)
2. FFmpeg – Best for Automation and Batch Jobs
Look, FFmpeg isn’t for everyone. It’s a command-line tool. No pretty buttons. But if you need to convert 200 MP4 files to MP3 at 3 AM via a cron job, nothing else comes close.
The basic command is dead simple:
ffmpeg -i input.mp4 -vn -acodec libmp3lame -ab 256k output.mp3
The -vn flag strips the video stream so you only get audio. The -ab 256k sets bitrate. Change it to 320k if you want maximum quality. For a batch of files in a folder:
for f in *.mp4; do ffmpeg -i "$f" -vn -acodec libmp3lame -ab 256k "${f%.mp4}.mp3"; done
That one-liner converted my test folder of 23 lecture recordings (total 8.4 GB) in under 4 minutes. No other tool on this list can match that throughput.
Pros:
- Fastest conversion speed of any tool tested
- Scriptable – automate thousands of conversions
- Granular control over codec, bitrate, sample rate, channels
- Free, open source, available everywhere
Cons:
- Command line only – steep learning curve
- Installation requires extra steps on Windows
Platform: Windows, macOS, Linux | Price: Free (open source, LGPL)
3. CloudConvert – Best Online Converter Overall
CloudConvert is the tool I reach for when I need a quick conversion and don’t want to think about it. Upload the file, pick MP3, click convert, download. That’s it.
The free tier gives you 25 conversions per day with files up to 1 GB each. For most people, that’s plenty. I converted my 1.2 GB test file and it failed (over the limit), but a 900 MB version went through in about 3 minutes including upload and download time on a 100 Mbps connection.
What sets CloudConvert apart from other online converters: you can adjust bitrate, sample rate, volume, and even trim the audio before converting. Most competitors just give you a convert button with no options.
Pros:
- Clean interface, no confusing ads
- 25 free conversions per day
- Bitrate and quality settings available
- API available for developers
- Supports 200+ file formats
Cons:
- 1 GB file size limit on free tier
- Conversion speed depends on your internet connection
- Paid plans start at $9.76/month for 1,000 conversions
Platform: Browser (any OS) | Price: Free (25 conversions/day) / from $9.76/mo
4. Online Audio Converter (123apps) – Biggest Free File Limit
This one deserves attention for a single reason: 2 GB file size limit on the free tier. That’s double what CloudConvert offers and 80x what Zamzar gives you.
The interface is basic but functional. You upload a file, pick the output format, adjust quality with a slider (from economy 64 kbps to max 320 kbps), and hit convert. There’s also a batch mode where you can upload multiple files at once.
One thing I appreciated: it shows the estimated output file size before you convert. My 47-minute talk at 256 kbps came out to 87 MB, exactly as predicted. Conversion took about 2 minutes after upload.
Pros:
- 2 GB file size limit – largest free limit I found
- Quality slider with file size preview
- Batch upload supported
- No account required
Cons:
- Some display ads (not intrusive but present)
- Limited format options compared to CloudConvert
- No API or advanced settings
Platform: Browser (any OS) | Price: Free (ad-supported) / $6.99/mo premium
5. FreeConvert – Good Middle Ground
FreeConvert sits between CloudConvert’s polish and 123apps’ simplicity. The free tier allows files up to 1 GB and 25 conversions per day, similar to CloudConvert.
The converter gives you control over audio codec, bitrate (up to 320 kbps), sample rate, and number of channels. You can also trim the audio by specifying start and end times, which is handy if you only want a segment of a longer video.
I ran into one annoyance: after conversion, the download link expires after 4 hours. If you forget to download, you have to convert again. CloudConvert keeps files for 24 hours.
Pros:
- 1 GB file size limit
- Audio trimming built in
- Good codec and bitrate options
- Batch conversion (up to 5 files)
Cons:
- Download links expire in 4 hours
- Ads on the free tier
- Slower processing than CloudConvert in my tests
Platform: Browser (any OS) | Price: Free (25/day) / from $12.99/mo
6. HandBrake – Already Installed? Use It
HandBrake is primarily a video transcoder, and a lot of video editors already have it installed. Here’s the thing – it can output audio-only files, but it’s not its main job and the workflow shows it.
To extract audio: open your MP4 in HandBrake, go to the Audio tab, set the codec to MP3, pick your bitrate, then under the Summary tab make sure the format is set to… actually, HandBrake doesn’t directly output MP3 files. It outputs M4A or you need to use the CLI version with specific flags.
Honestly, if you already have HandBrake for video work and occasionally need audio extraction, it works. But if MP4-to-MP3 is your primary need, VLC or FFmpeg are better choices.
Pros:
- Free and open source
- Queue system for batch processing
- Detailed audio encoding options
Cons:
- Doesn’t output MP3 directly from the GUI (M4A/AAC instead)
- Overkill for simple audio extraction
- Learning curve if you’ve never used it
Platform: Windows, macOS, Linux | Price: Free (open source, GPLv2)
7. Zamzar – Quick and Tiny
Zamzar has been around since 2006 and it shows – in both good and bad ways. The good: it’s dead simple. Upload, pick format, convert, download. No account needed. The bad: the free tier caps at 25 MB per file.
25 MB. That’s about 2-3 minutes of decent quality video. For a quick clip, fine. For anything longer, you’ll hit the wall immediately. My 1.2 GB test file? Not a chance.
The paid plans ($18/month for 200 MB, $36/month for 2 GB) feel expensive compared to CloudConvert at $9.76/month for 1 GB files. Zamzar’s main selling point at this point is brand recognition and the fact that it requires zero thought to use.
Pros:
- Extremely simple interface
- No signup required
- Email delivery option (they email you the converted file)
Cons:
- 25 MB free limit is unusably small for most video files
- Expensive paid plans relative to competitors
- Only 2 free conversions per day
Platform: Browser (any OS) | Price: Free (25 MB, 2/day) / from $18/mo
8. Any Video Converter – Best Windows GUI Option
If you’re on Windows and want something with a visual interface that isn’t VLC’s awkward converter, Any Video Converter is solid. The free version handles MP4 to MP3 without watermarks or time limits.
The workflow is straightforward: drag your MP4 into the window, select MP3 as output format, adjust bitrate if needed, click Convert. It processed my 1.2 GB test file in about 2 minutes, which is competitive with VLC.
The catch: the installer tries to bundle additional software. Pay attention during setup and uncheck everything you don’t want. Once installed, the actual app is clean and ad-free.
Pros:
- Intuitive drag-and-drop interface
- Batch conversion with progress tracking
- No file size or conversion limits
- Built-in video downloader (from supported sites)
Cons:
- Bundleware in the installer
- Windows only (no Mac or Linux)
- Free version occasionally nags about upgrading
Platform: Windows | Price: Free / $49.95 one-time (Ultimate)
How to Pick the Right Bitrate
This trips people up more than it should. Here’s the practical breakdown:
| Use Case | Recommended Bitrate | File Size (per hour) |
|---|---|---|
| Voice/podcast | 128 kbps | ~55 MB |
| Music (casual listening) | 192 kbps | ~82 MB |
| Music (good quality) | 256 kbps | ~110 MB |
| Music (maximum quality) | 320 kbps | ~137 MB |
For spoken word content like lectures, podcasts, or audiobooks, 128 kbps is genuinely fine. The human voice doesn’t need the frequency range that music does. Going higher just wastes storage.
For music, 256 kbps is the sweet spot. Most people can’t tell the difference between 256 and 320 kbps in a blind test. I’ve tried. Multiple times. With decent headphones. The difference is there if you’re an audio engineer listening for it, but for Spotify-trained ears, 256 does the job.
Desktop vs Online: Which Should You Use?
Here’s my honest take after testing both approaches for this guide:
Use an online tool when:
- You have 1-5 files under 1 GB each
- You don’t want to install anything
- You’re on a work computer with restricted software installation
- It’s a one-time job
Use desktop software when:
- Files are over 1 GB
- You need batch conversion (10+ files)
- You do this regularly
- Privacy matters (your files stay on your machine)
- Your internet is slow
The privacy point matters more than people think. When you upload a video to an online converter, it sits on their server during processing. Most services claim to delete files after a few hours, but you’re still trusting a third party with your content. For personal recordings or business meetings, desktop conversion keeps everything local.
Mobile Conversion: iPhone and Android
Quick notes on mobile because people ask about this constantly.
iPhone/iPad: The Shortcuts app can do it natively. Create a shortcut with the “Encode Media” action, set output to Audio Only, format to M4A (iOS doesn’t support MP3 encoding natively, but M4A works in most places MP3 does). For actual MP3 output, use the Media Converter app (free with ads) or an online converter in Safari.
Android: Install VLC for Android. Open the MP4, tap the three-dot menu, select “Convert.” Alternatively, the app “MP3 Video Converter” by Springwalk does exactly what its name says. Free version handles files up to 5 minutes; paid removes the limit for $2.99.
For the occasional conversion on mobile, online tools work fine too. CloudConvert’s mobile site is responsive and functional.
Common Issues and Fixes
Converted MP3 has no sound
This usually means the original MP4 had no audio track, or the audio was in a codec your converter doesn’t support (like Opus in some screen recordings). Open the MP4 in VLC and check Media > Codec Information. If there’s no audio stream listed, there’s nothing to extract.
Output file is much larger than expected
Check your bitrate setting. If you accidentally set it to 320 kbps for a 4-hour podcast, you’ll get a 2 GB MP3. Switch to 128 kbps for voice content.
Conversion gets stuck or takes forever
For online tools, this is usually a server-side issue. Try again later or switch to a different service. For desktop tools, check if your antivirus is interfering – some security software flags FFmpeg as suspicious because it can be bundled with malware (the official FFmpeg download is safe).
Audio is out of sync
This shouldn’t happen with MP4 to MP3 since you’re discarding video, but if it does, the source file probably has variable frame rate issues. Re-encode with FFmpeg using: ffmpeg -i input.mp4 -vn -acodec libmp3lame -ab 256k -ar 44100 output.mp3 to force a consistent sample rate.
My Recommendation
For most people: CloudConvert or Online Audio Converter (123apps) for occasional use. No installation, works immediately, handles files up to 1-2 GB.
For regular use or large files: VLC. You probably already have it installed. The conversion feature works reliably once you find it.
For batch jobs and automation: FFmpeg. Nothing else comes close for processing dozens or hundreds of files.
If you need other file format conversions beyond audio, take a look at our roundup of best free file converter tools – it covers video, document, and image formats too.
FAQ
Is it legal to convert MP4 to MP3?
Converting your own files is legal everywhere. The legal gray area is converting copyrighted content you don’t own. Recording a YouTube video and extracting the audio for personal use falls into a legal gray zone that varies by country. In practice, nobody has been prosecuted for converting a video to MP3 for personal use, but distributing converted copyrighted audio is a different story.
Does converting MP4 to MP3 lose quality?
Yes, technically. MP4 video files typically contain audio encoded in AAC format. Converting AAC to MP3 means re-encoding from one lossy format to another, which introduces a small amount of additional quality loss. At 256 kbps or higher, this loss is inaudible to most people. If quality is paramount, convert to FLAC instead of MP3 – it’s lossless, though files will be 5-10x larger.
What’s the best MP4 to MP3 bitrate?
256 kbps for music, 128 kbps for voice. Going above 320 kbps with MP3 is technically possible but pointless since the format maxes out there. If you need higher quality, use FLAC or WAV instead.
Can I convert MP4 to MP3 without installing software?
Yes. CloudConvert, FreeConvert, 123apps Online Audio Converter, and Zamzar all work directly in your browser. Upload the MP4, select MP3 as output, convert, and download. File size limits apply – 123apps has the most generous limit at 2 GB for free users.
How do I convert MP4 to MP3 on iPhone or Android?
On iPhone, use the Shortcuts app with an “Encode Media” action, or download Media Converter from the App Store. On Android, VLC for Android has a built-in converter, or use the MP3 Video Converter app by Springwalk. Online converters also work in mobile browsers.