Flash and debug STM32
from your browser

Skip the IDE install and toolchain setup. Plug in an SWD debug probe, open MCUHex, and you're flashing firmware, setting breakpoints, and streaming live variables — straight from a browser tab.

memory Works with ARM Cortex-M (STM32) via SWD debug probe
1
Install the tray app
A tiny bridge that lets your browser talk to your debug probe. Supports Windows amd64 and macOS arm64.
2
Plug in your probe
Connect an SWD probe (ST-Link, J-Link, DAPLink) to your target board.
3
Flash and monitor
Upload firmware, set breakpoints, watch live variables — all from the browser.

See it in action

Take a quick interactive tour to see how it works.

Get the Desktop App

A lightweight bridge app that lets your browser communicate with your MCU device. Install it once, and MCUHex will connect directly to your debug probe.

laptop_mac
macOS (Apple Silicon)
latest
desktop_windows
Windows (amd64)
latest

Installation (macOS)

1
Extract the .zip
Double-click the downloaded MCUHex-macos-arm64.zip to extract the app.
2
Move to Applications
Drag the MCUHex app into your Applications folder.
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.

What works today

Every capability below is shipped and live in the browser — connect a supported debug probe and you're using them.

Available
analytics

Live variable monitoring

Pick symbols from your ELF and watch them tick in real time with 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.

Available
bug_report

Source-level debugging

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

Available
visibility

Watch & inspect symbols

Watch project symbols with decoded values, auto-refresh on halt/step, and change highlighting.

On the roadmap

group_work Collaborative workspacesfolder_zip Firmware version managementinsights Performance analytics