Hardware Diagnostics & Electronics Lab

Read and write NFC tags directly from browser using Web NFC API. Create smart business cards and automation triggers.

Test and map game controllers using Gamepad API. Visual button mapping, analog stick calibration, and vibration testing.

View detailed information about connected USB devices using WebUSB API.

Test your webcam and microphone in-browser. Live video preview, resolution, FPS, and audio level meter.

Test your screen for dead or stuck pixels with full-screen colors, gradients, and gray sweeps — right in your browser.

Free online voltage divider calculator. Compute Vout from Vin, R1, and R2 with current and power, model loaded dividers, and reverse-solve R2 for a target voltage.

Free online voltage drop calculator. Estimate DC, single-phase, and three-phase AC voltage drop from AWG wire size, length, current, and material with temperature correction and 3%/5% limit checks.

Size copper traces from current and temperature rise using IPC-2221 formulas

Free online LED resistor calculator. Find the right current-limiting resistor from supply voltage, LED forward voltage, and target current, with the closest E24 standard value, power dissipation, and 4-band color code.

Compute 555 timer astable frequency, duty cycle, and monostable pulse width from R and C values, or reverse-solve R1 and R2 from a target frequency.

Decode 3-digit ceramic capacitor markings (104 = 100 nF) to pF, nF, and µF, or convert a capacitance back to its marking code. Supports R decimal notation and EIA tolerance letters — all in your browser.

Estimate how long a battery lasts from its capacity (mAh or Wh), voltage, and average current draw, with derating and reserve options.

Test mouse buttons, double-click speed, scroll wheel direction and step count, and live pointer coordinates in your browser - with a click-area heatmap. No install needed.