How Long Can the iPhone Record Audio?
By James Lee Phillips
Whether you're recording dictation, a business presentation, audio notes or music, your iPhone has a limit on how much audio it can record. A few minutes here and there isn't likely to cause much concern, but the iPhone may not be able to keep recording when a meeting or recital goes on for a half-hour, an hour or even longer. To get the most recording time, choose your recording app carefully, select the right audio options and be aware of how much space is left in your flash memory.
Choose Your App
The app you use will determine how long you can record and how successfully you can sync or process longer audio files. Native apps such as Voice Recorder and Voice Memo have been reported by some users as stopping after 30 minutes or having difficulty processing files that were over an hour long. GarageBand for iPhone will only record for a certain number of musical bars, but you can extend the recording time by lowering the song's beats per minute (BPM). Third-party apps such as iRecorder Pro and ProStudio promise "unlimited recording time," although any recording will be limited by file format and hardware specifications.
Fundamentally, your available recording time depends on the amount of free space on your iPhone. As a general rule of thumb, one free gigabyte allows you to record about 101 minutes of stereo uncompressed 44.1kHz WAV audio. Different generations of iPhones offer different amounts of storage; the original iPhone came with 4GB or 8GB of space, while the iPhone 5 comes in 16GB, 32GB and 64GB models. Some of the flash memory will already be used and reserved by your OS for apps and files, so you're likely to have less space to record — sometimes far less — than the full size of the drive itself. You can go to Settings|General|Usage to see exactly how much space you have to work with.
The length of recording time depends largely on the output file format used by your recording app. The iPhone supports many audio formats, each with different ratios of audio quality to file size. You'll fill up your free memory much faster with uncompressed WAV files than you will with MP3s, for example. Furthermore, many compressed formats offer bit rate (audio resolution) options which directly affect the size of the output file. For example, an MP3 or Apple Lossless at a 128k bitrate will take up less space than the same audio format at 192k.
While not technically increasing your potential recording time, you can keep your iPhone's flash memory as free as possible by choosing to upload or store recordings on a remote space. Apps such as SoundCloud or Cloud Audio Recorder still depend on free flash memory while recording, but allow you to store the results on their servers. Similarly, manually transferring your saved audio file to a desktop or laptop computer or external storage device (via iTunes or a third-party file manager app such as Air Sharing) once you have finished recording them will give you the maximum amount of free space for future recordings.
James Lee Phillips has been a writer since 1994, specializing in technology and intellectual property issues. He holds a Bachelor of Science in communications and philosophy from SUNY Fredonia.