Choosing the right audio format is important when starting an internet radio station. The format affects sound quality, bandwidth usage and whether your listeners can play the stream on their devices. The most common formats used for online radio are MP3, AAC, AAC+ and OGG. Each of them has different advantages, but for most broadcasters the choice is quite simple.

MP3

MP3 is still the safest format for internet radio. It is supported by almost every browser, mobile device, media player, smart speaker and radio app. If you are starting your first Shoutcast radio station, MP3 is usually the best option. It is easy to configure and works almost everywhere.

The main downside is that MP3 needs a higher bitrate to sound good compared to newer codecs. For music radio, 128 kbps MP3 is a common and reliable setting. For talk radio, 64-96 kbps may be enough. Best for:

• Maximum compatibility
• Shoutcast streams
• Beginners
• Public radio stations

Recommended setting: MP3 at 128 kbps.

AAC

AAC is a newer and more efficient format than MP3. It can provide better sound quality at the same bitrate, or similar quality at a lower bitrate.

This makes AAC a good choice if you want to reduce bandwidth usage while keeping good audio quality. It is widely supported on modern devices, especially smartphones and browsers. However, MP3 is still usually safer if you want your stream to work on as many devices and apps as possible. Best for:

• Better quality at lower bitrate
• Mobile listeners
• Modern devices
• Stations that want to save bandwidth

Recommended setting: AAC at 96-128 kbps.

AAC+

AAC+, also known as HE-AAC, is designed for low-bitrate streaming. It can sound surprisingly good even at 48-64 kbps, which makes it useful for mobile or low-bandwidth listeners. AAC+ is a good choice when bandwidth matters, but it may not be supported everywhere. For this reason, it is often better as an additional stream rather than the only format for your station. Best for:

• Low-bitrate streams
• Mobile listening
• Bandwidth saving
• Backup or secondary streams

Recommended setting: AAC+ at 48-64 kbps.

OGG and Opus

OGG Vorbis and Opus are open audio formats often used with Icecast. They can offer good quality and are popular in open-source environments. However, they are not always the best choice for a public radio station. Some apps, older devices and radio directories may not support them as well as MP3.

If you use Icecast and know your listeners can play OGG or Opus, they can be good options. For a general Shoutcast station, MP3 is usually a safer choice. Best for:

• Icecast servers
• Open-source setups
• Technical users
• Controlled listening environments

Recommended setting: OGG or Opus at 64-128 kbps.

Which format is best?

For most internet radio stations, the best starting point is MP3 at 128 kbps. It gives you good compatibility, simple setup and reliable playback for most listeners. If you want better quality at lower bitrate, choose AAC. If you need a very small stream for mobile users, choose AAC+. If you use Icecast and prefer open formats, consider OGG or Opus. Simple recommendation:

• MP3 – best default choice
• AAC – better quality and efficiency
• AAC+ – best for low bitrate
• OGG/Opus – good for Icecast and open formats

Final recommendation

If you are not sure which format to choose, start with MP3. A stream that works everywhere is usually better than a more modern format that some listeners cannot play.

For Free-Shoutcast.com users, MP3 is the most practical choice for a first radio station. Later, when your station grows, you can add AAC+ or another format as an additional stream for mobile and low-bandwidth listeners. Start simple, test your stream on different devices and choose the format that works best for your audience.