9M2PJU ESP32-C3 AdBlocker
Flash directly from your browser — no software install needed.
Click CONNECT and select your ESP32-C3's serial port.
How to flash
Use a data cable (not charge-only). The board should appear as a serial port.
The browser will ask permission to access the serial port. Select your ESP32-C3
(typically USB JTAG/serial debug unit or USB Serial Port) and click Connect.
ESP Web Tools will erase the flash and write the bootloader, partition table, firmware, and blocklist (~140k domains). This takes about 30–60 seconds.
Then click Visit Logs or close the dialog. The board will reboot.
The board starts a captive portal AP called C3AdBlock-Setup.
Connect to it from your phone/laptop, open http://192.168.4.1,
and enter your WiFi credentials.
Once on your WiFi, go to http://c3adblock.local (or the IP shown
on serial). The username is anything; the password is printed on the serial console
at boot (look for [cfg] dashboard password:).
What gets flashed
- Bootloader (offset
0x1000) — ESP32-C3 bootloader - Partition table (offset
0x8000) — dual-OTA + LittleFS layout - Firmware (offset
0x10000) — the ad-blocker application - Blocklist filesystem (offset
0x2b0000) — ~140k blocked domains (StevenBlack + Hagezi Light, WhatsApp/social safe)
After the initial flash, all updates (firmware + blocklist) happen over WiFi from the dashboard — no USB needed.
• Port not showing up? Try a different USB cable (must be data, not charge-only). On Linux, you may need to add a udev rule:
echo 'SUBSYSTEM=="tty", ATTRS{idVendor}=="303a", MODE="0666"' to
/etc/udev/rules.d/99-esp.rules, then sudo udevadm control --reload-rules.• Flash failed? Hold the BOOT button on the C3 while clicking Connect, then release after flashing starts.
• ModemManager interfering? (Linux)
sudo systemctl stop ModemManager