Choosing the Best Bitrate for Your Internet Radio Station

There are many different bitrates and audio file formats out there that you can use for your station's stream. But what is the real best one for you to use? It turns out, this is not a problem with a one-size-fits-all solution.

What is a Bitrate?

Bitrates determine how much data is transferred through an audio stream. The higher the bitrate, the more data is transferred. When more data is transferred, the audio is typically fuller and higher-quality. Audio bitrates are generally measured in kilobits per second (kbps). Most internet radio station hosting providers allow you to configure your bitrate up to a certain limit, which a good hosting provider tells you when you are purchasing your hosting plan.

Considering Your Audience

As with almost everything about an internet radio station, the right choice for your station depends mainly on your listener base. If your listeners are not audiophiles, then your main focus should not always be cranking the bitrate all the way to the maximum limit. This can cause excessive usage of data, throttling by your hosting provider, and slower server operations overall.

You should also take into account your audience's devices. If your audience is mainly listeners on mobile devices or cellular data connections, higher bitrates may not be the best idea. Once again, higher bitrates use more data. Extremely high bitrates like 320kbps use a considerable amount of data over time, and poor connections over cellular networks typically cannot sustain that level of data transfer.¹ This is also true on other types of lower-end devices, so if your audience skews older and uses these types of devices, steer away from ultra-high bitrates on your station.

File Formats Make a Big Difference

The audio format, also known as the audio codec, is another important piece of the puzzle to achieving the sound you want to hear on your station. Sometimes, the best audio format is not the one that is recommended by your hosting provider. For example, you may think that MP3 is the best format for streaming audio, because of how widely used it is. And while, sure, this is an amazing codec to use, it also is not the best codec you can use. There are other audio codecs that can achieve similar perceived quality to high-bitrate MP3 while being lower bitrate.

Okay, this is getting a little bit tricky. Let's break it down codec-by-codec so its easier to understand and choose what codec might be best for you to use.

MP3 Codec

MP3 is the most widely supported and popular audio file format in the world. MP3 is what is known as a lossily compressed audio format. The wide support is exactly why it's recommended by most internet radio station hosts. It also helps keep file sizes small by discarding unimportant parts of the file.²

AAC (Advanced Audio Coding)

AAC is the successor to MP3 and delivers extremely comparable or even better sound quality at lower bitrates than MP3. That means it can transfer less data and also provide better perceived audio quality. If audio quality is one of your main focuses as a station, AAC is a strong contender for the streaming format your station should use. AAC, like MP3, is widely supported; however, some older hardware players may not support AAC. This should only be true of considerably older devices; though, as the format was widely released all the way back in 1997.³

AAC+ (HE-AAC)

AAC+ is an enhanced version of AAC, created specifically for low-bitrate audio streaming (hence the "high efficiency"). High-quality audio can be achieved at very low bitrates (32-64kbps). This version of AAC is able to provide listeners with high-quality audio without breaking the metaphorical bandwidth bank. Even this version of AAC is very well-supported across even legacy applications and especially on modern browsers; however, compatibility may be an issue if you have a large listener base of people using older hardware players.⁴

HLS (HTTP Live Streaming)

HLS isn't an audio codec like MP3 or AAC. Instead, it's a delivery protocol that breaks your stream into small segments and can switch between different quality levels in real time as a listener's connection changes. Because of this, HLS is often paired with adaptive bitrate streaming, giving listeners on weaker connections a lower-bitrate segment and listeners on strong connections a higher-bitrate one, without ever cutting out.

This is different from VBR, which adjusts data usage based on how complex the audio itself is moment-to-moment; a quiet acoustic passage uses less data than a dense, layered mix, even within the same file. VBR tends to work best for pre-recorded content rather than live broadcasts, since it requires analyzing the whole file ahead of time.

CBR is what most internet radio stations use, live or pre-recorded. It keeps the bitrate locked throughout the entire time it's being streamed to the client, which makes it simpler to predict bandwidth usage and more reliable for live streams.

Specific Bitrate Recommendations: Case-by-Case

Every station has a different situation, so you should always make the final call on what's best for your station, and your budget. The guidelines below can, however, assist you in finding a good place to start. And, remember, you can almost always change your bitrate later!
64-96kbps (AAC/AAC+): Recommended for talk radio or stations where speaking takes up the vast majority of content, rather than music. Also recommended if people listening in on a mobile device or cellular connection is popular for your station. Recommended for stations that are music-focused with a lower bandwidth budget or larger listener base.⁵
128kbps (MP3/AAC): Good for general station use with all-around good quality. Recommended for stations that are music-focused with a standard bandwidth budget.
192kbps (MP3/AAC): Recommended for stations that are music-focused. Recommended for stations that get a strong listener base of people not on mobile networks or cellular data, and for stations with a higher bandwidth budget.
256-320kbps (MP3/AAC):* This is highly not recommended due to extortionate data consumption. Realistically, using these levels of quality only make* sense if you have a commitment to high-fidelity audio, or an audience largely made up of audiophiles.⁶

Calculating Your Allowed Bitrate

Something to lookout for is that your hosting provider may limit how much bandwidth per month you can use and not limit bitrates. This is important because high bitrates add up in total bandwidth/data transfer used over time. Confirm your limitations with an estimate of how much bandwidth a certain bitrate uses based on concurrent listeners and how long the average listener stays tuned in on our free bitrate bandwidth calculator.

So, What Bitrate Should I Use?

Ultimately, we recommend taking a look at all of the options first, then choosing the best bitrate for your station specifically. There is no one-size-fits-all answer. However, you need to make sure you choose the bitrate that is best for your station. Or, maybe choosing the bitrate yourself isn't the best option at all. If your hosting provider allows, it may be worth leaving the decision on the desired bitrate up to the user by dividing different bitrates into different mount points/streams. Just make sure you choose wisely, and if not, correct it later!

1. Live365 "Understanding Radio Streaming Formats & Bitrates" (https://live365.com/blog/understanding-radio-streaming-formats-bitrates/) ↩
2. MP3 on Wikipedia (https://en.wikipedia.org/wiki/MP3) ↩
3. AAC on Wikipedia (https://en.wikipedia.org/wiki/Advanced_Audio_Coding) ↩
4. HE-AAC on Wikipedia (https://en.wikipedia.org/wiki/High-Efficiency_Advanced_Audio_Coding) ↩
5. Triton Digital "Choose Audio Bitrate Settings" (https://help.tritondigital.com/docs/audio-bitrate-settings) ↩
6. iono.fm "Audio quality levels & file formats" (https://support.iono.fm/docs/stream-qualities) ↩