If you want to convert online videos into audio from various online streaming sources such as YouTube and many more streaming websites following steps will help you to do it without downloading any software.
1. Open any Video Streaming Website and open the video which you want to convert or extract the Audio from.
2. Copy the URL address from the browser's address bar.
3. Now go to MP3 Grabber website.
4. Paste the copied URL in the big box and click Grab It button.
5. It may ask your permissions to run the Java script. Though it's not necessary but depending on your browser and the version of Java software installed in your PC, allow the permission.
6. After allowing Java to run in the browser, a Java pop-up message will appear. Click Run button.
7. Now your browser may take few moments and will show you different audio formats, from which you can select the one you want to download. You can also change settings related to Bitrate, Channels and Sample rate if you want (otherwise defaults are perfect).
Note: If you only see the download button and not the Thumbnail Preview of the video then it means that the video is not loaded properly and cannot be downloaded. Close all the browsers and repeat the same steps told above. If again you don't see the Thumbnail Preview of the video, it means that the video cannot be downloaded (due to any reason)
8. Click the Download button, save the file anywhere in your computer and MP3 Grabber will begin the conversion process.
9. Once the conversion is complete, the file will be downloaded and saved in your computer. That's it.
So this is the easiest way to convert a online video to audio.