A free tool

SerialWizard: a serial monitor, plotter, Modbus master and ESP32 flasher

One small program for the bench: watch what a board prints, plot the numbers in it, poll a Modbus device and flash an ESP32, ESP32-S3 or ESP32-P4. Windows, macOS and Linux. Nothing to install, no account, and free for everybody.

Download SerialWizard Read the guide

SerialWizard's Monitor tab connected to COM8 at 115200 baud, showing an ESP32-S3 boot log ending in 'UI ready'. — The Monitor tab, reading an ES3C35P board as it boots.

Four tabs

What it does

Monitor

Any baud rate and line settings, DTR and RTS switches, and six views of the same bytes: text, ASCII, hex, hex with ASCII, decimal and binary. Switching view redraws what was already received. Search, a send box with history, and auto-reconnect when a board resets or is unplugged.

Plot

Numbers are picked out of each line as it arrives: temp:23.5C, hum:41%, plain columns, or a CSV header naming the columns. The axes scale themselves. Record a run, then save it as CSV or a PDF report with the chart and statistics.

Modbus

A Modbus RTU and TCP master. Read coils and registers, decode them as 16 or 32-bit integers or floats in any word order, and write single or many values. Every frame is shown in hex with its CRC checked. A built-in demo device lets you try it with no hardware.

Flash

Drop .bin files or a build folder onto it. The bootloader, partition table, app and merged images are recognised from their contents and put at the right address, and an address that would break the board is refused before anything is written. It verifies the write, then hands the port to the monitor so the first boot line is caught.

Download

Get SerialWizard

Each download is one self-contained program. Unpack it and run it.

It is not code-signed yet

SerialWizard does not have a Windows code-signing certificate or an Apple Developer ID yet, so your computer will warn you the first time you open it. Before you do, check that the file you downloaded is the one published here: its MD5 or SHA-256 should match the one listed under it.

Chrome or Edge may call the download suspicious or say it is not commonly downloaded. That is the browser's reputation check on a new program with no signature, not a virus found in it. Open the downloads list (Ctrl+J), choose to keep the file, then check its hash below before you open it.
Windows: in PowerShell, Get-FileHash -Algorithm MD5 SerialWizard-*-windows-x64.zip. When SmartScreen says "Windows protected your PC", click More info, then Run anyway.
macOS: in Terminal, md5 SerialWizard-*.zip. Open the app once, then go to System Settings > Privacy & Security and click Open Anyway.
Linux: md5sum -c MD5SUMS.txt or sha256sum -c SHA256SUMS.txt in the download folder.

The Windows download for 3.2.0 was scanned by VirusTotal on 23 October 2026 and none of its 66 security vendors flagged it: the VirusTotal report.

Design the screen it talks to.

LCD Wizard is a visual LVGL designer for ESP32 display boards. Lay out the screens, wire the hardware, and export the firmware SerialWizard flashes.

Open the designer