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Raspberry Pi GPIO Pinout
Look up the 40-pin Raspberry Pi header: physical pin numbers, BCM names, power rails, and which pins carry I2C, SPI, and UART.
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Raspberry Pi GPIO Pinout
Frontend preview — no upload or external service.
Pinout reference
Pin 3 = BCM 2 = SDA1, pin 5 = BCM 3 = SCL1, pins 1 and 17 are 3V3, pins 2 and 4 are 5V, and pins 6, 9, 14, 20, 25, 30, 34, 39 are ground.
How the Raspberry Pi GPIO Pinout works
- Choose whether you are working in physical pin numbers or BCM names — mixing the two is the most common wiring mistake.
- Highlight the bus you need to find its pins quickly.
- Check voltage before connecting: GPIO pins are 3.3 V and are not 5 V tolerant.
FAQ
Physical or BCM numbering?
BCM names are what most libraries expect, while physical numbers are what you count on the board. Pick one for a project and label your wiring with it, because pin 3 and GPIO 3 are different pins.
Are the GPIO pins 5 V tolerant?
No. They are 3.3 V, and applying 5 V can permanently damage the chip. Use a level shifter or a divider for 5 V devices.
How much current can a pin supply?
A few milliamps per pin, with a modest total across the header. Anything with a motor, a relay coil, or a long LED strip needs external power and a driver.
How we compare
| Feature | Online Tool Store | A CLI script | An IDE plugin |
|---|---|---|---|
| Physical and BCM side by side | ✓ | ✓ | Varies |
| Bus pins highlighted | ✓ | Manual | ✓ |
| Works offline once loaded | ✓ | ✓ | ✗ |
| No install | ✓ | ✗ | ✓ |
Raspberry Pi GPIO Pinout shows both numbering schemes together, because confusing physical pin 3 with BCM 3 is the classic first-project wiring fault.