How do I reduce the size of an audio file on my Android?
Android devices come with limited storage, so managing the size of audio files is important. Large audio files take up precious space and can slow down your device. Reducing audio file sizes has several benefits:
- Frees up storage space on your device
- Makes it faster and easier to share files through email, messaging apps, and cloud services
- Allows you to store more audio files given the storage constraints
- Reduces mobile data usage if streaming files
- Improves performance by reducing storage and memory demands
There are various techniques you can use to compress audio files on your Android device without sacrificing too much quality. This guide will go through the main methods available.
Check the audio format
Common audio formats like MP3 and AAC are already compressed. This means they take up much less space than uncompressed formats like WAV or AIFF (Source). Converting an uncompressed audio file to a compressed format can drastically reduce its file size without significantly impacting quality.
For example, an uncompressed WAV file may be 50-100 MB. Converting the same audio clip to MP3 format could reduce its size to just 5-10 MB. The original uncompressed WAV file is a lossless format that preserves 100% of the source audio data. The compressed MP3 format selectively discards audio data that is considered imperceptible to most listeners. This data removal allows the same audio clip to be stored in a much smaller package (Source).
So before trying other tricks, first check the audio format. Converting uncompressed clips to a compressed format like MP3 or AAC is usually the simplest way to significantly reduce file size.
Use a dedicated audio compression app
One of the easiest ways to reduce the size of audio files on Android is to use a dedicated audio compression app. Apps like Audiocompressor can re-encode your audio files at a lower bitrate to make the files smaller, often with little perceptible loss in quality.
Dedicated audio compression apps provide more advanced compression settings and algorithms compared to the built-in options in Android. You can precisely control the bitrate, sample rate, channels, and compression level when re-encoding your files.
The advantage of using a specialized app for compressing audio is that you can easily batch process multiple files. Some apps allow you to create presets for different levels of compression that you can quickly apply to batches of songs or audio clips.
Overall, dedicated audio compression apps give you more control and flexibility than Android’s default audio encoding options. So if you need to significantly reduce the size of multiple audio files, try using an app like Audiocompressor to efficiently re-encode the files at a lower bitrate.
Change bitrate settings
One way to reduce the size of an audio file on Android is to adjust the bitrate settings when encoding the audio. The bitrate determines how much data is used to represent the audio, measured in kilobits per second (kbps). A higher bitrate generally means better audio quality, while a lower bitrate results in a smaller file size. However, lowering the bitrate too much can negatively impact the audio quality by introducing compression artifacts and loss of detail.
According to the blog post What is Audio Bitrate, and How Does it Impact Audio Quality?, “Lower bitrates mean smaller files, but can reduce quality.” When choosing a bitrate, it’s important to balance between file size and quality based on your intended use case. For informal sharing, a bitrate of 128 kbps may suffice, while 192-256 kbps is recommended for music distribution platforms. Critical listening may require 320 kbps or higher to preserve audio fidelity.
Most audio editing apps like Audacity allow you to adjust the export bitrate. Some Android music players like JetAudio and neutron player also let you resample tracks to reduce bitrates. Just keep in mind that further lowering an already compressed file may degrade quality. You’ll achieve the best results by adjusting bitrate at the time of encoding.
Downsample for lower quality
Reducing the audio’s sampling rate and bit depth is one way to significantly reduce the file size, but this comes at the cost of lower audio fidelity. Downsampling refers to lowering the sample rate, while bit depth reduction means using fewer bits to store each audio sample. For example, downsampling from 48 kHz to 32 kHz sampling rate, and reducing bit depth from 16-bit to 8-bit, will shrink the file size by half. However, this will introduce audible distortions, noise, and loss of high frequency content. As such, downsampling is only suitable for situations where ultimate audio quality is not critical, such as converting files for mobile use or streaming over limited bandwidth.1
The process of downsampling can introduce aliasing, which is unwanted high frequency noise caused by the attempted reconstruction of a higher sample rate from a lower one. Proper downsampling requires the use of low-pass filters to avoid aliasing. There are dedicated apps and software that can downsample audio files while minimizing quality loss. However, for important audio that will be closely listened to, it’s recommended to preserve the original high sample rate and bit depth. The fidelity loss from compression may be unacceptable for professional, critical listening purposes.2
Use Android’s MediaCodec API
For advanced users, encode files programmatically with MediaCodec – Allows fine-grained control over compression parameters.
The MediaCodec API introduced in Android 4.1 (Jelly Bean) provides low-level access to media codecs for encoding and decoding audio and video on Android devices. Using MediaCodec directly gives developers precise control over compression parameters like bitrate, sampling rate, frame rate etc. This allows advanced compression of audio files by reducing quality in a controlled manner.
MediaCodec can be used to develop custom audio compression apps or integrate compression features into an existing Android app. Sample code for audio encoding with MediaCodec is available on sites like Stack Overflow. However, working with MediaCodec requires strong development skills and deep knowledge of audio encoding.
While powerful, MediaCodec may be overkill for basic audio compression needs. For most users, a dedicated compression app provides an easier way to shrink audio files on Android.
Try different audio players
Some audio players for Android have built-in compression features that can reduce the size of audio files when played. This happens through algorithms that optimize and compress the audio data internally, without actually changing the source file itself. Testing out different audio players is an easy way to potentially uncover extra savings in storage space used by audio files.
For example, the Poweramp music player for Android offers audio compression options like volume normalization, dynamic compression, and downsampling. Enabling these can compress the audio at playback to use less storage and bandwidth (Source). So even without changing the original files, just using Poweramp could save space versus other players. Similarly, apps like JetAudio, Neutron, and UAPP also advertise advanced audio optimizations to reduce the data required for music playback.
It’s worth experimenting with different highly-rated Android audio apps to find one that sounds great while potentially compressing audio on-the-fly. Just installing a new player and using it normally could lead to lower storage usage over time. Look for players mentioned as having audio enhancers, compressors, normalizers, or other optimization features designed to minimize data usage.
Store in the cloud
One way to reduce the size of audio files on your Android device is to store the original high-quality files in the cloud instead of on your phone. Services like Google Drive and Dropbox offer cloud storage that you can access from anywhere. When you upload audio files to the cloud, the storage service will often compress them to save space on their servers. According to Reddit users, Google Drive does compress uploaded audio files, but claims to use “lossless compression” so there is no reduction in quality.
The benefit of storing the original versions in the cloud is that you can download compressed, lower-quality versions to your Android device while retaining access to the full quality recordings if needed. This saves storage space on your phone while still giving you access to the uncompressed audio when you have a better internet connection. Just be aware that downloading and streaming the files may incur mobile data charges.
Delete unnecessary metadata
Metadata like album art, ID3 tags, and chapter markers can significantly increase the file size of audio files without affecting audio quality. For example, according to a discussion on Hydrogenaud.io, simply changing ID3 tags can alter an MP3 file’s size even if the audio data remains the same (source). Removing non-critical metadata like cover art, lyrics, and excessive ID3 tags can often reduce file size substantially with minimal impact on quality.
Try using an audio file metadata editor like MP3Tag to view and delete any unnecessary metadata bloating your files. Focus on metadata that does not provide essential information or directly impact the listening experience. For example, cover art may be nice to have but is non-essential if your goal is to shrink the file size. Chapters also take up space but can be removed if you don’t need to jump to specific points within long files. Eliminating metadata cruft can be an easy “quick win” for reducing audio file size.
Conclusion
To summarize, the most effective options for reducing the size of an audio file on Android include using a dedicated audio compression app, changing the bitrate settings to use a lower quality, and downsampling to reduce the sampling rate. These can significantly reduce file size with minimal impact on quality.
The tradeoff is that the more you compress the audio or reduce the bitrate/sampling rate, the lower the audio quality becomes. You’ll want to experiment to find the optimal balance between small file size and acceptable quality for your needs. Just be aware that excessive compression can introduce artifacts, muddy the sound, or make the audio tinny.
Less extreme options like deleting metadata, trying different audio players, or uploading to the cloud have less impact on file size. But they may be worthwhile first steps before resorting to heavy compression or downsampling that degrades the listening experience.
Overall, aim for the smallest file size you can achieve while retaining adequate quality for your purpose. And consider cloud storage or streaming if you need access to high-quality original files without filling up local storage.