How can I convert MP4 to MP3 online for free? Choose a MP4 file from your computer or drag and drop it into Restream’s audio converter. Select Convert and the converter will start processing. Download your MP3 file when it’s ready. Choose a MP4 file from your computer or drag and drop it into Restream’s audio converter. Select Convert and the converter will start processing. Step 1: Upload MP4 Files Drag and drop or click Choose Files button to import MP4 file you want to convert. Step 2: Choose Audio File(s) Format Select a desired output format from the Convert all to > Video/Audio tab, then hit the Start Convert button to experience the lightening-fast conversion speed. Step 3: Save Converted MP3 File Just hit the Download button to save your converted files. Congrats! Done! Download your MP3 file when it’s ready. MP4, sometimes called MPEG4, is one of the most common video formats. MP4 was developed to be easily played and shared. It was originally developed by the Moving Picture Experts Group (MPEG) but has become an ISO standard, meaning that it’s now maintained by the International Organisation for Standardization. As MP4 is a standardised format, it will normally play easily on most devices and media players, including Windows Media Player, QuickTime, and VLC. MP4 is usually the preferred format for uploading videos to YouTube, Vimeo or other websites. MP4 videos are made up of video and audio elements that are compressed separately. The video part is usually compressed with MPEG-4, and the audio is usually compressed using AAC, which is the audio format associated with iTunes. Because both file elements are compressed, MP4s normally have a smaller file size than many other video formats, but still maintain relatively high quality for sharing online. MP3 Audio Format MP3 Converter MP3 is the most common format for storing and playing digital music. It’s short for ‘MPEG-1 Audio Layer 3’, and it was developed in the early 1990s as a way of compressing audio to create smaller files that could be easily shared and stored without losing too much sound quality. MP3 is a universal format maintained by the International Office for Standardization (ISO). MP3 tracks will play on almost any device and with most media players, including Windows Media Player and Apple Music. Digital music took off in the 1990s and 2000s, and many users used media players to ‘rip’ CDs, or download tracks from sites like Napster, turning MP3 into the most common audio format. Because MP3 uses ‘lossy’ compression that can’t be reversed, some music listeners prefer to use other formats such as FLAC, even if the file sizes are bigger.