Online Tools
Free, browser-based tools for electronics and makers. No installs, no accounts — everything runs locally in your browser.
Serial Monitor
Connect to a USB device like an RP2040, Arduino, or ESP32 and view live serial output, right in your browser.
Ohm's Law Calculator
Enter any two of voltage, current, resistance, or power to solve for the other two.
Resistor Color Code Calculator
Decode resistor bands into ohms, or enter a value to find the matching color bands.
LED Resistor Calculator
Find the right current-limiting resistor for an LED based on supply voltage and target current.
Capacitor Code Decoder
Decode ceramic capacitor markings like 104 or 47n into a capacitance value.
Voltage Divider Calculator
Enter Vin plus any two of Vout, R1, or R2 to solve for the missing value.