Flash and monitor STM32
from your browser

Skip the IDE install and toolchain setup. Install one small tray app, plug in your debug probe, and you're flashing firmware and monitoring live variables — straight from a browser tab.

memory Works with ARM Cortex-M (STM32) via SWD debug probe

All you need is an STM32 board, a USB cable, and a debug probe — built into Nucleo and Discovery boards.

1
Install the tray app
A tiny helper that bridges your browser and your debug probe. Works on Windows and macOS (Apple Silicon). On Linux, or if you would rather not run an unsigned app, run the open-source server from source.
2
Plug in your probe
Connect a probe (ST-Link, J-Link, DAPLink) to your computer over USB and to your board's SWD pins. Nucleo and Discovery boards have the probe built in — one USB cable is all you need.
3
Flash and monitor
Flash your firmware (.bin or .hex), pick variables from your ELF, and monitor them live — all from the browser.

See it in action

One recording, start to finish: ELF in, symbols resolved, values coming off the board.

Get the Tray App

A lightweight tray app that bridges your browser and your debug probe. Install it once — it sits in your tray, ready whenever you hit Connect in MCUHex.

The apps are built from the public mcuhex-sdk repository and are not code-signed. If you would rather not run an unsigned app, the same server runs from source.

laptop_mac
macOS
Apple Silicon
latest
desktop_windows
Windows
amd64
latest
terminal
Linux
from source
open source

Installation (macOS)

1
Open the .dmg
Double-click the downloaded MCUHex-macos-arm64.dmg to mount the disk image.
2
Move to Applications
Drag the MCUHex app onto the Applications shortcut in the mounted image.
3
Bypass Gatekeeper
macOS will block the app on first launch because it isn't signed with an Apple Developer certificate. Right-click (or Control-click) the app and select Open, then click Open in the dialog. You only need to do this once.

Probe not detected, or SWD failing after the install? The troubleshooting guides walk through every error MCUHex reports.

What works today

Everything marked available is shipped and live in the browser — connect a supported debug probe and you're using it.

Available
analytics

Live variable monitoring

Pick symbols from your ELF and monitor them in real time — decoded values, change highlighting, and Chart.js-powered graphs.

Available
memory

Firmware flashing over SWD

Drop in a .bin or .hex. Erase, program, and verify phases stream live, then the MCU auto-resets.

Coming soon
bug_report

Source-level debugging

Set breakpoints in your source, step over lines, inspect the call stack and registers — DWARF powered.

On the roadmap

group_work Collaborative workspacesfolder_zip Firmware version managementinsights Performance analytics

Which of these lands first depends on demand — see the plans.