Raspberry Pi GPIO 40-pin (J8) Pinout
The 40-pin GPIO header on modern Raspberry Pi boards - power, I2C, SPI, UART, and GPIO.
Overview
The 40-pin J8 header is on the Raspberry Pi B+ and every flagship model since (Pi 2/3/4/5, Zero). It is two rows of 20 on 2.54 mm pitch. Pins 1-26 are identical to the original 26-pin header for backward compatibility.
All GPIO logic is 3.3 V and NOT 5 V tolerant. The header provides 3V3, 5V, ground, and BCM-numbered GPIO with alternate functions for I2C1, SPI0, and the primary UART.
Pinout
| Pin | Name | Function | Description |
|---|---|---|---|
| 1 | 3V3 | POWER | 3.3 V power |
| 2 | 5V | POWER | 5 V power |
| 3 | GPIO2 (SDA1) | DATA | I2C1 data |
| 4 | 5V | POWER | 5 V power |
| 5 | GPIO3 (SCL1) | CLK | I2C1 clock |
| 6 | GND | GND | Ground |
| 7 | GPIO4 (GPCLK0) | CLK | General-purpose / clock |
| 8 | GPIO14 (TXD) | UART | UART transmit |
| 9 | GND | GND | Ground |
| 10 | GPIO15 (RXD) | UART | UART receive |
| 11 | GPIO17 | SIGNAL | General-purpose GPIO |
| 12 | GPIO18 (PCM_CLK) | SIGNAL | General-purpose / hardware PWM0 |
| 13 | GPIO27 | SIGNAL | General-purpose GPIO |
| 14 | GND | GND | Ground |
| 15 | GPIO22 | SIGNAL | General-purpose GPIO |
| 16 | GPIO23 | SIGNAL | General-purpose GPIO |
| 17 | 3V3 | POWER | 3.3 V power |
| 18 | GPIO24 | SIGNAL | General-purpose GPIO |
| 19 | GPIO10 (MOSI) | SPI | SPI0 MOSI |
| 20 | GND | GND | Ground |
| 21 | GPIO9 (MISO) | SPI | SPI0 MISO |
| 22 | GPIO25 | SIGNAL | General-purpose GPIO |
| 23 | GPIO11 (SCLK) | SPI / CLK | SPI0 clock |
| 24 | GPIO8 (CE0) | SIGNAL | SPI0 chip enable 0 |
| 25 | GND | GND | Ground |
| 26 | GPIO7 (CE1) | SIGNAL | SPI0 chip enable 1 |
| 27 | GPIO0 (ID_SD) | I2C / DATA | HAT ID EEPROM I2C data (reserved) |
| 28 | GPIO1 (ID_SC) | I2C / CLK | HAT ID EEPROM I2C clock (reserved) |
| 29 | GPIO5 | SIGNAL | General-purpose GPIO |
| 30 | GND | GND | Ground |
| 31 | GPIO6 | SIGNAL | General-purpose GPIO |
| 32 | GPIO12 (PWM0) | SIGNAL | Hardware PWM0 |
| 33 | GPIO13 (PWM1) | SIGNAL | Hardware PWM1 |
| 34 | GND | GND | Ground |
| 35 | GPIO19 (PCM_FS) | SIGNAL | General-purpose / PWM1 |
| 36 | GPIO16 | SIGNAL | General-purpose GPIO |
| 37 | GPIO26 | SIGNAL | General-purpose GPIO |
| 38 | GPIO20 (PCM_DIN) | SIGNAL | General-purpose GPIO |
| 39 | GND | GND | Ground |
| 40 | GPIO21 (PCM_DOUT) | SIGNAL | General-purpose GPIO |
Notes
- GPIO is 3.3 V logic, NOT 5 V tolerant.
- Pins 27/28 (ID_SD/ID_SC) are reserved for the HAT identification EEPROM.
- Pins 1-26 match the original 26-pin header.
Reference: Raspberry Pi GPIO documentation / pinout.xyz· verified 2026-06-27