Serial Port Tester
Free online Serial Port tester tool, Web Serial API, UART/COM debug
What is Serial Port Tester?
Serial Port Tester is a free online tool for testing serial port communication using the Web Serial API. It allows you to connect to UART/COM ports directly from your browser, send and receive data, and debug serial devices.
Browser Support
Web Serial API is supported in Chromium-based browsers (Chrome, Edge, Opera) on desktop. Firefox and Safari do not currently support this API. Make sure you're using a compatible browser.
How to Use
1. Configure the serial port settings (baud rate, data bits, stop bits, parity). 2. Click 'Connect' and select a serial port from the browser's port picker. 3. Enter your message in the input field and click 'Send'. 4. View sent and received data in the log panel. 5. Click 'Disconnect' to close the port when done.
HEX Mode
Enable 'Send as HEX' to send raw hexadecimal data (e.g., 'AA BB CC' for bytes 0xAA, 0xBB, 0xCC). Enable 'Show as HEX' to display received data in hexadecimal format instead of text.
▶Why is the Connect button not working?
▶Can I use this with USB-to-Serial adapters?
▶What baud rates are supported?
▶Is my data sent to any server?
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