Tool
Serial port terminal in your browser
Test communication with a serial device from your browser, with nothing to install: send ASCII or hex, watch what comes in and drive the DTR and RTS lines. Needs Chrome or Edge on a computer.
Control lines
CTS0DSR0DCD0RI0
Received · RX 0 · TX 0
Show as
Connect a port to start. Incoming data shows up here.
Send as
Supports \r, \n, \t and \xHH (for example, \x1B).
Everything stays between this page and the port: nothing is sent to the internet. On Arduino or ESP32 style boards, toggling DTR or RTS may reset the board.
Video tutorials
How to use it
- Connect the device to your computer, through a USB-serial adapter or the board itself.
- Pick the baud rate and format (for example, 115200 8N1) and press Connect.
- The browser lists the available ports; on Windows they show their COM number. Pick yours.
- Type and send in ASCII or hex. Whatever the device answers shows up in the window.
What it is for
- Testing AT commands on modems and GSM, Bluetooth or WiFi modules.
- Watching what the firmware of an Arduino, an ESP32 or a PIC prints.
- Checking a USB-serial adapter (CP210x, CH340, FTDI) and its DTR, RTS, CTS and DSR lines.
- Testing binary protocols by sending hex bytes.
- Field testing from any computer, with no software to install.
What you need
Chrome or Edge on Windows, macOS, Linux or ChromeOS: they provide the browser Web Serial API. Firefox and Safari have no serial port access. The page sends nothing to the internet: data only travels between the browser and the port.