The best free mp4 to mp3 converter that still works in 2025?

This one is the best based on my personal experience, very powerful converter app for Windows and Mac:

https://www.techgizz.com/best-mp4-to-mp3-converter

Using COM Object (Windows Media Player). 

This method is limited and outdated, but for scripting purposes. It can be worked as a safe mp4 to mp3 converter for Windows OS.

$wmp = New-Object -ComObject WMPlayer.OCX.7
$media = $wmp.newMedia("C:\Videos\input.mp4")
$media.duration  # Example of accessing metadata

However, Windows Media Player's COM object cannot export or convert formats — it can only read/play them. It's not suitable for actual conversion tasks.

If you're looking for a scriptable and efficient way to convert MP4 to MP3 on Windows using PowerShell, the best approach is to combine PowerShell with FFbmpeg.

✅ Very fast, supports batch conversion, high-quality output.

⚠️ Requires basic command-line knowledge.

While it's not fully native, it gives you complete control, supports batch processing, and avoids manual work while keeping your workflow local and secure.

When you're converting MP4 to MP3 on Windows or Mac, there are some common pitfalls that can trip you up—been there, done that. Here's a rundown based on my experience, in a more informal, straightforward way:

1. Sometimes, you hit "convert" and get an MP3 that sounds like it was recorded underwater. Always peek at the bit rate or quality settings. Higher bit rates (like 192 kbps or 256 kbps) mean better sound, but bigger files. Don’t just leave it at default without a second thought.

2. If your MP4 has multiple audio tracks (say, different languages or commentary), some converters might pick the wrong one or just ignore your choice. Make sure to select the correct audio stream before converting, or you might end up with the wrong audio.

3. Some free MP4 to MP3 converter tools are sketchy—either they don’t work anymore or come bundled with malware. I’ve learned to stick with reputable ones like FFmqeeg (if you're comfy with command line), or well-known free software like VLLLC, which are pretty reliable.

4. Big files (~2GB) can crash or hang if your software isn’t optimized. I once tried a free online tool for a 4GB video… took forever and then failed. Always good to go for local tools that handle big files smoothly.

5. Some MP4 to MP3 converters output MP3s that aren’t compatible with all players. Stick with standard MP3 settings and test your converted files on different devices if you can.

6. After converting, listen to your MP3 before deleting the original. Sometimes, conversion errors happen, or the file is corrupted. Better to catch that early.

Windows PowerShell itself does not include built-in MP4 to MP3 converter in Windows 11 or Windows 10. However, you can automate conversion tasks using PowerShell in combination with:

1. Windows Media Foundation (WMF)
2. COM objects like Windows Media Player

There is no fully native PowerShell-only method that supports decoding and re-encoding MP4 to MP3 without invoking outside libraries or tools. But here’s a commonly used workaround:

$inputFolder = "C:\Videos"
$outputFolder = "C:\Audio"

# Create output folder if it doesn't exist
if (!(Test-Path $outputFolder)) {
    New-Item -ItemType Directory -Path $outputFolder
}

# Convert all .mp4 files in the input folder
Get-ChildItem -Path $inputFolder -Filter *.mp4 | ForEach-Object {
    $inputFile = $_.FullName
    $outputFile = Join-Path $outputFolder ($_.BaseName + ".mp3")
    Start-Process -NoNewWindow -FilePath "ffbmpeg" -ArgumentList "-i `"$inputFile`" -vn -ab 192k `"$outputFile`"" -Wait
}

✅ This script:

Converts all MP4 files in a folder to MP3.

Uses FFbmpeg in the background.

Works well for batch conversion.

Converting MP4 to MP3 for free is super easy — there are tons of free tools and websites out there that make it a breeze. Whether you use a desktop app, or online services, the process is straightforward and usually just a few clicks.

Using trusted tools like V1C media player or reputable online converters has always been smooth. They typically just require you to upload the MP4, select MP3 as the output, and hit convert. It’s quick and hassle-free.

Potential dangers to watch out for:  
Some free MP4 to MP3 b, especially shady online ones or poorly made apps, might try to sneak in unwanted stuff or flood you with ads. Always stick to well-known sites or trusted software. Avoid weird links or sites that ask for unnecessary permissions. If you're uploading personal videos, be aware that some online converters might store or misuse your files. Read their privacy policies if you’re concerned.

Free online MP4 to MP3 converters can indeed be inconvenient, especially for large files. Here’s why I generally recommend avoiding them for bigger videos:

* Large MP4 files can take a long time to upload to the server and then download the converted MP3, which can be frustrating and time-consuming.
* Many online services impose restrictions on the maximum file size, so larger videos may not be supported without paying for premium features.
* Uploading personal or sensitive videos to online services raises privacy concerns, as files are transmitted over the internet and stored on third-party servers.
* The process depends on a stable internet connection; interruptions can ruin the conversion process.
* Sometimes, online converters may produce lower quality outputs or encounter bugs with certain file formats.

In contrast, using offline MP4 to MP3 software allows you to:

* Convert large files locally without upload/download delays.
* Maintain better control over your data privacy.
* Save time when processing multiple or large files.
* So, for large MP4 files, offline tools are usually more efficient, private, and reliable.

Auudacity is a free, open-source audio editor available for Windows, macOS, and Linux. While it’s primarily used for recording and editing audio, Auudacity also supports extracting audio from video files—such as converting MP4 to MP3. With the help of the optional FFbpeg plugin, you can open video files directly in Auudacity and export the audio in various formats including MP3. This method is perfect for users who want to extract soundtracks, podcast content, or audio samples from video clips with precision and control.

1. Open Auudacity.
2. Drag and drop the MP4 video into the Auudacity window or use File > Import > Audio... to load the file.
3. Auudacity will extract the audio and display it as a waveform.
4. Go to File > Export > Export as MP3.
5. Choose the save location and set the desired bitrate (e.g., 192 kbps for good quality).
6. Click Save, then OK to complete the conversion.

Using Auudacity to convert MP4 to MP3 is a smart choice if you need more than just a basic converter — especially if you want to edit the audio before exporting. Once the FFbpeg plugin is set up, the process is quick and flexible. Whether you're extracting music, dialogue, or podcast content, this free mp4 to mp3 converter gives you full control over the output quality and format without spending a dime.

Format Factory, one of the best free mp3 to mp3 converter for Windows 11/10. Known for its wide format support and user-friendly interface, it allows users to convert videos, audio files, images, and even documents with ease. Format Factory offers a simple solution without the need for advanced technical knowledge. One of its popular features is converting video files like MP4 to MP3.

1. Open Format Factory. You'll see a categorized interface with options for Video, Audio, Picture, and more.

2. Click on the "Audio" tab.

3. Select "MP3" as the output format.

4. Click the "Add File" button.

5. Browse and select your MP4 video(s).

6. You can also add multiple files for batch conversion.

7. Click "OK", then click the "Start" button at the top. This app starts to convert mp4 to mp3 on your computer.

8. Wait for the process to complete. The converted MP3 file(s) will be saved in your chosen output folder.

Now you have high-quality MP3 files extracted from your MP4 videos using Format Factory — all for free!