Whether you’re a podcast producer, a musician, or a DJ who creates music mixes, you need to know how to compress audio files to reduce their size. It can also be helpful to know how to compress audio files when you just want them to take up less space on your device.
Here are several easy and effective ways to 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 use a lower bitrate, stripping out a good portion of an audio file’s data. This reduces the overall sound quality but also makes it a much smaller file and therefore easier on your hard drive.
Lossy formats are fine in most situations. As long as you don’t set the bitrate too low it’s unlikely you’ll be able to tell much difference between lossless and lossy audio, especially if you’re listening on your phone through earbuds.
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.
Take a quick look at how file compression works for a closer look at what happens when you compress a file.
1. Compress MP3 Files With iTunes
Once you’ve decided which audio file type to use, you can easily convert the file using iTunes.
Click Preferences in the iTunes dropdown 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 dropdown menu.
For most people, going with an MP3 format will be preferable. 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. Apple iTunes will then compress the audio file based on the quality settings you selected and drop the new file right into your iTunes music.
2. Compress Audio Files With Monkey’s Audio
Most people can’t hear a huge difference between a lossy 320kbps MP3 and a lossless 1411kbps 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 on Windows 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)
3. Reduce Audio File Size 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:
- Open your file in Audacity
- Go to File > Export and select the format you want to save the file in
- Under Format Options choose the Bitrate Mode—variable or constant—then set a Quality
- Hit Save to save a newly compressed file
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)
4. 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. It’s a very quick and easy way to reduce MP3 size.
Online tools aren’t just for compressing audio files. Take a look at our guide to the best free online audio editors for some even more powerful apps.
5. How to Reduce Audio File Size in Android
If you need to compress an audio file on mobile there are a number of Android apps that will do the job.
Audio Video Manager is one app that does the job pretty well. You can select your audio file and choose to convert it into a host of formats, including MP3, AAC, or even the lossless FLAC.
You can do a straight file conversion, or choose to compress it at the same time. Simply toggle the Compress option on or off, then choose whether you want a variable or constant bitrate, and select the bitrate itself. You can pick anything from a very low quality 32kbps up to an excellent 320kbps.
Finally, hit the Convert button to begin.
Download: Audio Video Manager (Free)
Choose Your Method and Start Compressing
So now you know how to compress MP3 and other audio files. Any of the tools listed above will do the job, and they’re mostly straightforward to use.
Compressing audio is essential when you’re recording it yourself, otherwise you’ll end up with massive files that are too big to share or use conveniently. But that’s only one part of the process. Check out our tips to help you record better audio to make your recordings sound even more professional.