How to flash or update Meshtastic firmware

Check the chip first

The method depends on the microcontroller. Look at the chip column in the device list.

• ESP32 / ESP32-S3 (for example Heltec V3 and V4): flash with the web flasher over USB serial. See also ESP32 vs nRF52.
• nRF52840 (for example Heltec T114, RAK WisMesh Pocket): the official docs call it the easiest to update; no driver or software install is needed on any platform.

Before flashing

1. Use a data cable. Test it by copying a file to a phone.
2. Attach the antenna. Do not power the radio without one.
3. Back up your config. The ESP32 flashing page says a full wipe and reinstall resets settings, and advises exporting your configuration first and loading it back afterwards.
4. Install a serial driver if needed. ESP32 devices need serial drivers; nRF52, RP2040 and RP2350 typically do not. CP210x and CH340 are the common USB-serial chips on boards, but check your board's page for which one it uses.

Flash an ESP32 board with the web flasher

1. Open flasher.meshtastic.org. The docs list Chrome or Edge as the supported browsers, because the tool uses the browser's serial port access.
2. Connect the board and choose it from the device list. Pick the right board and the right band version.
3. Choose a firmware version (see below).
4. Start the flash and wait until it finishes. The board reboots into Meshtastic.
5. Pair with the app and set your region.

The docs describe the CLI script as the manual process, and an external serial adapter as a last resort.

Flash an nRF52 board

Drag and drop is the recommended method: put the board in bootloader mode so it shows up as a USB drive, then copy the firmware file to it. Exact steps are on the Meshtastic pages "Drag and drop" and "Entering bootloader mode" for your device, linked from the nRF52 flashing page. A factory erase is optional, and suggested before installing when stored data may change between releases. nRF52 devices can also get over-the-air updates from a phone over Bluetooth.

Which firmware version?

On 2026-11-05 the GitHub "Latest" release is v2.7.26, published 2026-06-24, and titled "Beta". Newer v2.8.x builds exist but are marked Alpha or pre-release, and some 2.8 builds were revoked. The docs site already describes 2.8. Meshtastic labels every build Alpha or Beta, so no build is called "Stable".

A cautious choice is the GitHub "Latest" release; if you want new 2.8 features such as signed broadcasts, accept that they are pre-release. Check the releases page again before you flash, because this changes often.

Full erase or update?

An update keeps your settings; a full erase wipes them. Use a full erase when moving between very different versions, or when the node behaves strangely after an update. Back up first.

Common problems

• Board not listed in the browser. Try another cable and USB port, and install the serial driver.
• Flash stalls. Re-enter the bootloader and retry.
• Wrong band flashed. The firmware chooses frequency by region, but the hardware has a band: a 915 MHz board must not be used as an 868 MHz one. See frequencies.

For more errors see the troubleshooting guide.