Whether you’re a podcast producer, a musician, or a DJ who creates music mixes, compressing audio files to reduce their size is an essential skill. It can also be helpful for the average person who enjoys listening to music or podcasts because smaller files mean less memory used on your device.
One of the main factors that influences an audio file’s size is bitrate. Put simply, bitrate is the amount of data processed over a given period of time. Files with higher bitrates sound better but require more memory. Audio with lower bitrates makes for smaller files, but sound quality is often sacrificed. The bitrate and filetype you need depends on the type of audio, what it’s used for, and who will be listening.
Here are four tools that’ll help you reduce large audio files down to a more manageable size:
Should You Choose Lossless or Lossy?
The first step to reducing the size of audio files is to recognize whether your audio is “lossless” or “lossy”.
Lossless formats have all of the original data intact and are therefore much bigger files. Lossy formats strip out a good portion of an audio file’s data, reducing the overall sound quality but also making it a much smaller file and easier on your hard drive.
Lossy formats are fine in most situations. Somebody listening to music or podcasts using their smartphone and earbuds won’t be able to tell much difference between lossless and lossy audio.
That said, if storage space isn’t an issue and you have high-quality speakers or headphones, a lossless format might be the way to go. Lossless formats also allow you to “future-proof” your audio, should you ever acquire better equipment for listening. You can always convert lossless audio to a lossy format, but you can’t convert lossy audio back into higher-quality lossless formats.
Convert Using iTunes
Once you’ve decided the audio file type you’re going to use, you can easily convert the file using iTunes.
Click Preferences in the iTunes drop down menu and navigate down to Import Settings.
A new window will pop up, in which you can change the way files are imported by picking a different option in the Import Using drop-down menu. For most people, going with an MP3 format will be preferrable. If you want, you can opt to make the quality slightly lower to save additional space by clicking on Settings > Custom.
Next, right click on the file you want to compress and select Create MP3 Version. iTunes will then compress the audio file based on the quality settings you selected and drop the new file right into your iTunes music.
Most people can’t hear a huge difference between a lossy 320 kbps MP3 and a lossless 1,411 kbps file, so if you’re a casual listener, a lossy format with solid bitrate should work. On the other hand, serious audiophiles and sound geeks can be a very particular bunch, and they don’t like their sound quality messed with.
If you absolutely need your music in a lossless format, an audio compressor such as Monkey’s Audio should do the trick.
The service compresses lossless files without compromising the sound quality, and it offers open-source code so developers can use it in their own programs. Perhaps the best feature of Monkey’s Audio? It costs nothing.
Download: Monkey’s Audio (free)
Compress with Audacity
Using iTunes is an easy way to convert audio files, but not everyone is an Apple or iTunes user. Another go-to tool used for audio compression is Audacity. The software is available for most operating systems.
Audacity has plenty of features for recording and editing audio, but it also compresses audio files. The user interface may be intimidating, especially for those who have never used sound editing software before, but using it to reduce file size is fairly straightforward:
- First, click Edit and Open to choose the file you’d like to shrink.
- Next, click Project Rate, which allows you to lower the audio’s sampling rate, and in turn its file size.
- Also, if having the audio file in stereo isn’t essential, select Split Stereo Track, then select Mono. This means the audio will now play using one track as opposed to two (stereo), further reducing the file size.
Audacity also allows you to manipulate the audio’s actual soundwaves. As they are already silent, you can select flat parts of the wave and delete them. After all of these steps, click File and select Export as MP3 to convert the file to the storage-friendly format.
Download: Audacity (free)
Use a Web Compressor
If you don’t want to download and install software, you could try using an online service instead. Most of these tools offer many of the same features as offline tools.
One great option is 123apps’ Online Audio Converter. You can convert an audio file from either your computer or online storage services such as Google Drive and Dropbox.
It has an easy-to-use interface which allows you to select the format you want. Typical formats such as MP3, WAV, M4A, and FLAC are available, but there are also more unusual offerings such as the iPhone ringtone format. A slider allows you to adjust the bitrate between 64, 128, 192 and 320 kbps, while the Advanced Setting tab lets you adjust things such as sample rate and whether you want mono or stereo output.
Once those selections are made, simply click the Convert button.
Additional features include the ability to convert multiple files simultaneously and a way to extract an audio track from a video.
Lastly, the developer says the files are automatically deleted from its servers a few hours after you’re done working on them, meaning nobody else will have access to them.
Choose Your Method and Start Compressing
There are a number of tools available to compress audio files, and they’re mostly straightforward to use. A lot depends on whether you want to use a web app or downloaded software.
Because of the vast number of tools available, we’d love to hear your input. Which tool to do find to be the most reliable? Have you found a web app that outperforms 123apps’ Online Audio Converter? Or do you just stick with iTunes?
As always, you can leave us you opinions and thoughts in the comments section below.