GuidesOctober 16, 20269 min read

Internet Radio Bitrates and Audio Codecs Explained Simply

Bitrate and codec names decide how a station sounds and how much data it eats. Here is how MP3, AAC, HE-AAC, Opus and Ogg Vorbis compare, and what each one costs on a mobile plan.

Written byice Radio FM

Codec and bitrate: the two numbers behind every station

The bitrate field on a station page is easy to skip: MP3 128 kbps, AAC 96 kbps, Opus 64 kbps. On ice.radio.fm those details sit right under the play button, and they predict two things you actually care about: how the station will sound and how much of your mobile data it will burn.

A codec is the compression recipe, and the bitrate is how much data the recipe is allowed to use every second. Together they decide whether a jazz station sounds warm at home and whether an all-news stream survives a month on a small data plan. The streams listed in the directory are published by the stations themselves; ice.radio.fm links to and plays them, and this guide is about understanding what you are pressing play on.

A codec (short for coder-decoder) squeezes audio so it fits through a network connection. MP3 has been around since the early 1990s and is still the most famous audio format in the world. AAC arrived later and was designed to offer more compression with higher fidelity than MP3. Bitrate is simply the amount of data carried per second, in kilobits per second (kbps). More kilobits means more detail survives the trip, which is why the same codec sounds better at 128 kbps than at 64 kbps, and also why it costs more data.

A codec decides how efficiently audio is compressed.
The bitrate decides how much data goes through per second.
Higher bitrate usually means better sound and bigger data use.
Comparing bitrates only makes sense inside the same codec.

The codecs you will actually meet on internet radio

Five codecs cover almost every stream you will find. MP3 is the classic, still treated by many stations as the default quality level at 128 kbps stereo. AAC (technically AAC-LC) is its successor, and Apple's own guidance is to use it for anything above 80 kbps; formal listening tests found AAC at 96 kbps runs about even with MP3 at 128 kbps.

HE-AAC, often sold under the name aacPlus, is the low-bitrate workhorse. It adds spectral band replication and, in version 2, parametric stereo, which keeps sound stereo at very low rates. Apple recommends HE-AAC v1 for 32 to 80 kbps, HE-AAC v2 for 16 to 40 kbps, and says quality at 64 kbps compares with AAC-LC at 96 kbps. That is why so many mobile-friendly streams are 64 kbps HE-AAC.

Ogg Vorbis is the open codec that powered a generation of independent Icecast stations before Opus existed; you still see it listed at 128 kbps or higher. Opus is the modern open standard, standardized by the IETF. It handles speech and music in one codec, works down to 6 kbps, and Icecast has supported Ogg Opus streams since version 2.4. All major desktop browsers play it, and iOS Safari added support in recent versions.

Talk radio and speech: how much bitrate is enough

Speech is far easier to compress than music, so talk stations get away with very low bitrates. The Xiph project behind Opus and Vorbis recommends around 24 kbps mono for audiobooks and podcasts, and 10 to 24 kbps for voice calls. A 32 kbps mono stream is plenty for most talk and news stations.

This is why news and talk stations so often list 24, 32, or 64 kbps streams. They stay clear on a phone speaker and cost almost nothing on a data plan. When a station offers both a 32 kbps and a 128 kbps stream, speech is the case where the low one is a genuinely good choice, not a consolation prize.

Talk and news sound good from about 24 kbps up.
32 kbps mono is a practical default for speech.
A low-bitrate talk stream costs pennies on a data plan.

Music: where bitrate starts to matter

Music needs more data than speech. For stereo music streaming, Xiph recommends Opus at 64 to 96 kbps and notes that Opus beats MP3, AAC, and Vorbis at those rates. Apple's recommended range for AAC-LC starts above 80 kbps, and MP3's long-running reputation as good enough is built around 128 kbps stereo.

In practice, below about 96 kbps complex tracks start to sound thin or washy, while speech at the same rate sounds perfectly fine. On Wi-Fi, 128 kbps is a safe default for music and sounds good on most headphones. A few stations stream at 192 or even 320 kbps for listeners with good speakers, but the data cost roughly doubles or triples, so those streams make the most sense at home.

How much data does streaming radio use per hour?

You can estimate this yourself with one formula: bitrate in kbps, multiplied by 3600 seconds, divided by 8 to convert bits into bytes, then divided by 1000 to get megabytes. Written out: kbps x 3600 / 8 / 1000 = MB per hour. At 128 kbps that is 128 x 3600 / 8 / 1000 = 57.6 MB per hour.

Put those numbers in calendar terms. One hour of listening a day at 128 kbps comes to roughly 1.7 GB a month. The same hour at 64 kbps is about 0.9 GB, and a talk station at 32 kbps costs about 0.4 GB. That is the difference between a stream that hides quietly in your plan and one that shows up on your bill.

32 kbps: about 14.4 MB per hour
64 kbps: about 28.8 MB per hour
96 kbps: about 43.2 MB per hour
128 kbps: about 57.6 MB per hour
192 kbps: about 86.4 MB per hour
320 kbps: about 144 MB per hour

Picking a stream when a station offers several

Many stations publish the same program at two or three bitrates. The right pick depends on where you are listening.

On a mobile data plan: take the Opus or HE-AAC stream at 64 kbps or below.
On a commute with a decent signal: 96 kbps is a good middle ground for music.
At home on Wi-Fi: take the highest bitrate on offer, usually 128 kbps or more.
For talk or news: the lowest listed stream is usually enough.
In a browser or old player: MP3 and AAC are the safest bets, though Opus now plays in all major browsers.

Why 128 kbps is still the yardstick

128 kbps stereo MP3 became the internet radio default in the 2000s and never really left. Reference streams set up for testing player compatibility still use it as the baseline, which is why so many station pages list MP3 128 kbps or AAC 128 kbps first.

The catch is that 128 kbps means different things in different codecs. Because AAC and Opus compress more efficiently, a 96 kbps AAC stream can match or beat a 128 kbps MP3 stream, and HE-AAC delivers comparable quality at 64 kbps. So when two stations both claim 128 kbps, listen before you judge. And if one stream is 64 kbps HE-AAC and another is 64 kbps MP3, take the HE-AAC one.

The short version: what to remember about bitrates

Codec and bitrate together decide sound quality and data use; neither number means much alone.
Speech is fine at 24 to 64 kbps. Music wants at least 96 kbps, with 128 kbps the comfortable default.
The data formula is kbps x 3600 / 8 / 1000 = MB per hour, so 128 kbps costs about 57.6 MB per hour and 64 kbps about half that.
HE-AAC and Opus give the most quality per kilobit, which makes them the smart picks on mobile.
Stations publish these streams themselves; the directory just links to and plays them. A lower bitrate means a lighter stream, not a lesser station.

Frequently Asked Questions

Is 128 kbps good enough for music?

Yes, for most listening. 128 kbps stereo has been the standard quality level for internet radio for years and sounds good on typical headphones and speakers. Stations that want more headroom stream at 160 or 192 kbps, and audiophile streams go higher, but 128 kbps is a safe default for music on Wi-Fi.

What bitrate is best for talk radio?

Speech stays clear at surprisingly low bitrates. A 32 kbps mono stream is plenty for talk and news, and 24 kbps works for podcasts and audiobooks. Because voices compress so well, talk stations often use 24 to 64 kbps streams, which also keep mobile data use very low.

How much mobile data does streaming radio use per hour?

Use the formula bitrate times 3600 divided by 8 divided by 1000 to get megabytes per hour. A 128 kbps stream uses about 57.6 MB per hour, 64 kbps uses about 28.8 MB, and 32 kbps uses about 14.4 MB. One hour a day at 128 kbps is roughly 1.7 GB per month.

Is HE-AAC better than MP3?

At equal bitrates, usually yes. HE-AAC was built for low-bitrate streaming and uses spectral band replication to reconstruct higher frequencies, so a 64 kbps HE-AAC stream sounds close to a 96 kbps AAC stream. MP3 remains the most compatible format, but HE-AAC gives better sound per kilobit, especially on mobile.

What does aacPlus mean?

aacPlus is the marketing name for HE-AAC, High Efficiency Advanced Audio Coding. Version 1 adds spectral band replication, and version 2 adds parametric stereo, which lets the codec keep a stereo image at very low bitrates. It is why you see streams like 64 kbps HE-AAC v2 stereo that sound much better than their size suggests.

Does a higher bitrate always sound better?

Not automatically. A 64 kbps HE-AAC stream can sound better than a 128 kbps MP3 stream because the codec does more with less data. Within one codec, higher bitrate does mean less compression and better quality, but the difference between 128 and 192 kbps is small for most listeners and ears.