How to Build an ESP32 Internet Radio

Updated 3 October 2026

An ESP32 is a Wi-Fi microcontroller that costs a few euros, and with a small audio board it plays internet radio on its own: no computer, no app, on the air a few seconds after you plug it in. It is less capable than a Raspberry Pi internet radio — no web player, no big music library — but it is cheaper, uses very little power and makes a good first electronics project.

What you need

• An ESP32 board with PSRAM. The ESP32-audioI2S library used in Option 2 needs PSRAM and a multi-core chip: an ESP32-S3 board with PSRAM is its main target today, and a basic classic ESP32 board without PSRAM (such as a plain WROOM-32 dev board) will not run that sketch. The finished firmware in Option 1 is more forgiving: yoRadio has a buffer setting for boards without PSRAM, and Ka-Radio32 plays MP3 only over I2S on a board without it (AAC needs PSRAM or a VS1053 decoder).
• An audio board. A MAX98357A I2S amplifier drives a small speaker directly; a PCM5102A I2S DAC gives a line output for an amplifier or powered speakers. Some older projects use a VS1053 decoder board instead.
• A speaker and a USB power supply. Optional extras: a small display for the station name, and a rotary encoder or a few buttons.

Option 1: a finished firmware

• yoRadio — web radio firmware built on the ESP32-audioI2S library. You manage the station list from a web page on your network, and it supports displays, remote controls and MQTT. It can import KaRadio station lists.
• Ka-Radio32 — the ESP32 version of the long-running KaRadio project, also with a web interface.
• ESP32Radio-V2 by Edzelf — the maintained successor of the original ESP32-Radio, with a VS1053 decoder or I2S output.

Each has its own wiring notes and flashing instructions on GitHub; follow the ones for the audio board you bought.

Option 2: a few lines of Arduino code

With the ESP32-audioI2S library, a working radio is short:

#include <WiFi.h>
#include "Audio.h"

Audio audio;

void setup() {
  WiFi.begin("your-network", "your-password");
  while (WiFi.status() != WL_CONNECTED) delay(500);
  audio.setPinout(26, 25, 22);   // BCLK, LRC, DOUT: match your wiring
  audio.setVolume(12);
  audio.connecttohost("https://example.com/stream");
}

void loop() {
  audio.loop();
}

Check the library's own examples for the version you install; its details change between releases. The pin numbers above suit a classic ESP32 dev board. On an ESP32-S3, GPIO 22 to 25 do not exist and GPIO 26 to 32 are used by the flash and PSRAM, so choose other free pins, for example 4, 5 and 6 on many S3 dev boards, and pass them in the same BCLK, LRC, DOUT order.

Choosing streams that play well

• MP3 at 128 kbps or less is the safest choice. AAC needs a board with PSRAM (or a VS1053 decoder). HLS addresses ending in .m3u8 depend on the library and firmware, so test one before relying on it.
• https costs the chip extra work. If an https stream stutters and the station also offers an http address, try that.
• Getting the addresses: every station page on 72FM has a Stream address panel with a Copy button. For many stations at once, the free M3U playlists by country and genre are plain text files: open one and copy the lines you want into your firmware's station list.

Why build one

A radio you built plays whatever stream addresses you give it. It does not depend on a manufacturer's station directory, which is what left many shop-bought Wi-Fi radios silent — internet radio stopped working tells that story.