Choosing and building firmware¶
The firmware builder offers ready profiles and custom builds for ESP8266, ESP-01S, ESP32 and ESP32-C3. The plugin catalog comes from the firmware source manifests. Every custom result is tied to an exact source commit and configuration, including the task limit.
| Board | Custom task slots | Default |
|---|---|---|
| ESP8266 / ESP-01S | 1–5 | 4 |
| ESP32 / ESP32-C3 | 1–16 | 16 |
Task slots reserve RAM even when unused. Build-time RAM percentages do not measure the minimum runtime heap; test the actual device and workload. ESP-01S is API-only and requires an external programmer.
Choose a board, a ready profile or your own features. Dependencies and required modules are enabled automatically. Selections survive tabs, board changes and language changes when browser storage is available. New custom builds consume quota; cached results and joining the same active build do not start another workflow. Signing in through the cloud provides the account quota.
Queue, running, completed, failed and network-paused states are separate. You can check the status manually on the builder page. Waiting is bounded to 25 minutes. History can resume a build after reloading. Refresh the page if the source catalog changes. Old partial or unverifiable custom results must be rebuilt.
First USB installation¶
Download and extract the complete installer ZIP. It includes firmware, LittleFS
and, for ESP32/C3, bootloader, partition table and boot_app0. Offsets and SHA256
are in flash.json; config.json records the selected features.
python -m pip install esptool==4.11.0
python flash.py
python flash.py --port COM3 --confirm-first-install
Without confirmation, the script only verifies files. The final command writes the images and replaces configuration. Use your actual COM/tty port. ESP32 and ESP32-C3 use different bootloader offsets; do not reuse another board's command.
Older ready profiles may have no installer ZIP. Firmware and LittleFS alone are not a complete first-install kit for an empty ESP32/C3. Choose a custom build and download its complete installer bundle.
Existing devices¶
Use the matching firmware and LittleFS with the board's OTA page, one file at a time. OTA does not replace the bootloader or partition table. USB filesystem installation replaces configuration; make a backup first. ESP-01S requires a programmer. Before reducing task slots, make sure the saved tasks fit the new limit.
Need another feature?¶
The source repositories are private. Select supported features in the public builder. If the device or action you need is missing, contact us with its model and expected behavior.