How to Record Computer Audio AND MIC as MP3 on Windows PC (FREE) - OBS Studio Tutorial
Learn how to record computer audio and your mic as an MP3 on a Windows PC for free. This step-by-step tutorial uses OBS Studio, VLC, and Audacity.
Key Takeaways
Recording internal computer audio along with an optional microphone input is a highly useful skill for creators, gamers, and professionals. While Windows PCs don't offer a built-in one-click solution for exporting mixed audio directly to an MP3, you can easily set up a completely free workflow using professional open-source software.
In this guide, you will learn how to capture system audio and microphone input, convert the recording to a universal MP3 file, and trim and boost the volume so it sounds perfectly crisp.
Note: Only record audio you have permission to capture.
Tools Required for this Tutorial
To achieve a polished MP3 audio file, we will be using a combination of three free, open-source programs.
FAQ
Why does OBS Studio save my audio recording as a video file?
OBS Studio is primarily a video broadcasting and screen recording software, so it defaults to exporting video formats like MP4. Because it lacks native MP3 export, this workflow involves capturing a low-resolution video file and then extracting the audio using VLC Media Player.
Once you have downloaded and installed OBS Studio, open the program. Even though OBS is primarily a video broadcaster, it is an incredibly powerful audio recorder. We just need to optimize the settings for audio-only capture.
Click on Settings and configure the following three tabs:
Output Settings
Go to the Output tab.
Ensure you have a Recording Path set up (e.g., your Desktop) so you know where your files are being saved.
Set the Recording Quality to High Quality.
Set the Recording Format to MP4. (Note: OBS Studio doesn't currently support native MP3 export, which is why we record in the universal MP4 format and convert it later).
Audio Settings
Navigate to the Audio tab.
Configure where your Desktop Audio and Mic/Auxiliary Audio are coming from.
If you have a specific microphone plugged in, select it from the dropdown, or leave it as Default.
Video Settings
Navigate to the Video tab.
Change the Output (Scaled) Resolution to the smallest size available in the dropdown.
Change the Common FPS Values to 30.
Why change video settings? Because OBS Studio saves the file as a video by default. Since we are only interested in the audio, shrinking the video resolution prevents the file from becoming unnecessarily large.
Click OK to save your settings.
Step 2: Record Your System Audio and Microphone
Back on the main OBS interface, look at the Audio Mixer at the bottom of the screen. You will see inputs for both your Desktop Audio and your Mic.
Checking Your Levels
Play some sample audio on your computer to see the Desktop Audio meter move.
Speak into your microphone. If you are recording your voice over computer audio, consider lowering the Desktop Audio slider slightly so your voice isn't drowned out.
Important: Ensure your microphone audio isn't hitting the red zone. If the meter exceeds 0 dB, your audio will clip and sound distorted.
If you only want internal computer audio and do not want to record your microphone, click the speaker icon next to your mic to mute it.
Start Recording
Click Start Recording.
A prompt will appear warning you that no video sources are being captured. Click Yes to continue, since we only care about the audio.
Play the audio you want to capture, and speak into your mic if desired.
When you are finished, click Stop Recording.
You will now have an MP4 file saved to your designated recording path. Double-click it to verify that your audio was successfully captured.
Step 3: Convert the MP4 to MP3 Using VLC
Because the file is currently an MP4 video, we need to extract the audio into an MP3 format using VLC Media Player.
Open VLC Media Player.
In the top menu, click Media and select Convert / Save.
Drag and drop your newly recorded MP4 file into the file selection box at the top.
Click the Convert / Save button at the bottom of the window.
In the next window, click the Profile dropdown and select Audio - MP3.
Click Browse to set the destination file. Choose a location (like your Desktop) and name your file (e.g., output.mp3).
Click Save, then click Start.
After a brief moment, VLC will finish extracting the audio, leaving you with a standard MP3 file.
Step 4: Trim and Normalize Audio in Audacity
While you now have an MP3, it likely has silent gaps at the beginning and end, and the overall volume might be too quiet. We can clean this up perfectly in Audacity.
Installation Note: When downloading Audacity, select the option to download without Muse Hub. Upon launching, click "Disable UUID" to turn off usage tracking, and close out of the Cloud Setup dialog box by clicking "Don't show this again at startup."
Trim Blank Space
Drag and drop your MP3 file directly into the Audacity window to reveal the audio waveforms.
Click the Selection Tool (the "I-beam" cursor icon).
Click and drag over the flat areas of silence at the beginning and end of your recording.
Press the Delete key on your keyboard to remove the dead space.
Normalize Audio Volume
System audio is recorded at your computer's set volume, which often translates to a quiet MP3. Normalizing brings the audio up to a loud, professional standard without distorting it.
Select the entire clip by clicking the header area of the audio track.
Go to the top menu and click Effect > Volume and Compression > Normalize....
Keep the default settings and click Apply. You will visibly see the waveforms get larger.
Export the Final MP3
Click File > Export Audio > Export to Computer.
Set the Format to MP3 Files.
Name your final file (e.g., final.mp3) and choose your save destination.
Optionally, you can click Edit Metadata... to add track details.
Click Export.
Double-click your final MP3 file to preview your completed, polished audio recording!
Next Steps
Now that you have all of these powerful, free tools installed on your Windows PC, you can expand your content creation skills even further. Check out these related tutorials:
Want to skip OBS? If you only want to record computer audio (without a microphone), you can do it natively inside Audacity. Learn how here: Record computer audio with Audacity
Ready to capture video? Now that OBS Studio is configured, you can easily add video capture to your workflow. Learn the best settings here: How to Screen Record
How can I prevent my microphone audio from sounding distorted?
Before you start recording in OBS, check your levels in the Audio Mixer. Speak into your microphone and ensure the volume meter stays out of the red zone (below 0 dB). If the meter exceeds 0 dB, your audio will "clip" and sound distorted. You can adjust the volume slider directly in the mixer to safely lower your input level.
Is there a way to record computer audio without downloading OBS?
Yes! If you only need to capture your internal system audio and do not need to record a microphone simultaneously, you can do this natively using Audacity. For step-by-step instructions, check out this tutorial on how to record computer audio with Audacity.
Can I use this same software to record my screen along with the audio?
Absolutely. Since OBS Studio is designed for video capture, you are already halfway there. You just need to add a video source (like a Display Capture) and adjust your video settings for high-quality resolution instead of scaling them down. For a full guide, watch this tutorial on how to screen record.
Are OBS Studio, VLC, and Audacity really free to use?
Yes, all three programs used in this workflow, OBS Studio, VLC Media Player, and Audacity, are completely free, open-source applications trusted by millions of creators. There are no hidden paywalls or watermarks.
