Flash a board over USB
Plug an ESP32 in and this reads back what it is — chip, flash size, PSRAM, partition layout — then writes the build that matches it and puts it on your WiFi. No drivers, no esptool, no zip to unpack.
Nothing is written until you have picked a build and seen the list of exactly what will be written. Your settings are kept where the build allows it — it says which before it starts — and can be saved to your machine first.
Needs Chrome, Edge or Opera on a desktop. Safari has no Web Serial API and neither does Firefox, though a Firefox add-on that adds one works here.
Talking to the board…
Syncing with the bootloader and reading the flash layout.
What is on the other end of the cable
Chip
Flash layout
Read from the board itself, not guessed from what you told us.
Which board is it?
The chip cannot tell us this — an MCP2515 on SPI and a built-in CAN controller look identical from here. Builds that cannot run on what was detected are shown with the reason.
Before it writes anything
What gets written
Your settings
Writing to the board
Leave the cable alone until this finishes.
Flashed, and the board has restarted
Network
This firmware is free and stays that way. If it saved you a weekend, buy me a coffee.
Put it on your network
The board is still on the cable, so it can take these now. Your passphrase goes down the USB lead to the board and nowhere else — this page has no server to send it to.
Or type it in
That did not work
A board already open in a serial monitor cannot be opened here as well — close it and try again. Some boards also need the boot button held while connecting.