Free Online Serial Monitor
Read Arduino, ESP32, and USB serial device output directly in a desktop browser.
Connection
Choose the baud rate your firmware uses, then connect to a USB serial device from a Chromium-based desktop browser.
Serial Data Text Box
0 characters captured
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DaqSense adds saved profiles, parser rules, live tables, formulas, raw capture, and CSV exports for hardware test workflows.
How This Online Serial Monitor Works
This free online serial monitor uses the browser's Web Serial API to request access to a USB serial device, open the port at your selected baud rate, and append incoming bytes to the text box above. It is useful for quickly checking Arduino serial output, ESP32 debug logs, boot messages, and simple sensor streams without installing a separate serial terminal.
Privacy and Device Access
The serial connection runs locally in your browser. The page does not send captured serial data to DaqSense servers. Your browser will ask you to choose a port before any connection opens, and you can disconnect from the page at any time.
Browser Compatibility
Web Serial is available in Chromium-based desktop browsers such as Chrome and Edge on secure pages. If your serial device does not appear, check that the USB cable supports data, the correct driver is installed, and no other serial monitor already has the port open.
Common Baud Rates for Arduino and ESP32
Arduino sketches often print serial data at 9600 or 115200 baud. ESP32 projects commonly use 115200 baud for application logs, and 74880 baud can be useful for some boot messages. The selected baud rate must match the value used by your firmware, such as Serial.begin(115200).
Need structured logging instead of a quick text capture? DaqSense is built for repeatable USB serial test workflows with parser rules, profiles, formulas, raw capture, and CSV exports.