Background: the browser flasher, firmware versions and open source
What technically happens when you click "Connect & flash", which firmware versions exist for the Nerdminer V2, and when to use which route.
memory How does the browser flasher work technically?
The bitminer24 browser flasher is built on ESP Web Tools, an official open source library from Espressif, the maker of the ESP32-S3 chip inside the Nerdminer V2. As soon as you click the flash button, your browser requests access to the USB port through the Web Serial API. The ESP32-S3 is put into boot mode automatically, the firmware file is streamed into your RAM, verified and then written to the chip's flash memory. That is exactly the procedure esptool.py uses on the command line. No communication with our servers takes place during flashing: your computer talks directly to the miner.
lock What is the Web Serial API, and is it safe?
The Web Serial API is a W3C specification that lets a web page talk to serial devices on the USB port, after explicit user confirmation. Every connection requires a click in a browser dialog where you pick the specific port. The page only gets access to the one port you grant. All of it runs 100% client side in the browser: no data upload, no cloud server, no telemetry. Chrome, Edge, Brave and Opera currently support the Web Serial API on desktop operating systems. As of 2026, Safari, Firefox and mobile browsers do not.
history Nerdminer V2 firmware versions at a glance
The Nerdminer V2 firmware is developed on GitHub in the official repository. The main versions are listed below (hash rate figures are typical values from community testing and can vary with the hardware batch and ambient temperature):
- 1.6.x (legacy): typically ~150 to 180 KH/s, more frequent Wi-Fi disconnects, some display glitches. No longer recommended.
- 1.7.x (transitional): typically ~190 to 210 KH/s, noticeably more stable connection.
- 1.8.0 to 1.8.2: typically ~220 to 240 KH/s, reworked hashing routine.
- 1.8.3 (currently recommended): typically ~230 to 250 KH/s, final bug fixes, faster reconnect after a Wi-Fi drop. This is the version the browser flasher installs here.
compare_arrows Browser flasher vs esptool: which one when?
Both methods install exactly the same original firmware. The difference is the workflow:
| Criterion | Browser flasher (this page) | esptool / klassisch |
|---|---|---|
| Time needed | ~3 minutes, no setup | ~15 minutes including Python & drivers |
| Software required | Just a Chromium browser | Python 3, esptool.py, USB-Treiber |
| Operating system | Windows, macOS, Linux (Desktop) | Windows, macOS, Linux |
| Browser requirement | Chrome, Edge, Brave, Opera | None, it runs in a terminal |
| Eigene Custom-Firmware | No, only our verified builds | Yes, any .bin file |
| Recommended for | 99% of users, the standard update | Entwickler & Custom-Builds |
We only recommend the classic esptool method if you want to build your own custom firmware, are using a browser without the Web Serial API, or simply prefer the command line for another reason. There is a separate step-by-step esptool guide for the Nerdminer V2 in the knowledge section.
code About the open source firmware (GPL-3.0)
The Nerdminer V2 firmware is licensed under the GNU General Public License v3.0. At bitminer24 we host exactly the unmodified original build from the official release: no fork, no baked-in pool defaults, no telemetry, no hidden modifications. Source code and licence: BitMaker-hub/NerdMiner_v2 LICENSE.
shopping_bag Still need hardware?
We sell both devices with a printed guide, preconfigured firmware and 2 to 3 business days delivery from Stuttgart: the Nerdminer V2 from 48.99 € as the entry-level device and the NerdNOS for considerably more hash rate. Both with the full 2-year statutory warranty and support from Germany.
