The web application is here.

When using a custum partition, you may need to adjust the maximum upload size in your boards definition.
The IDE has no way to read the custom partition, see this issue.

By default many of the custom paritions in boards definition have a 16MB max upload size, so if your board has less than 16MB flash memory, for example 4MB is typical, the compiler will report a wrong space occupied by your sketch.

To fix this, you have to edit the Espressif boards.txt file, which is normally located in
[your drive]\[your name]\AppData\Local\Arduino15\packages\esp32\hardware\esp32\[esp32 core version]

This is a very large file and you need to search for your specific board and change the line (here for the ESP32S3 Dev Module) :
esp32s3.menu.PartitionScheme.custom.upload.maximum_size=16777216
to
esp32s3.menu.PartitionScheme.custom.upload.maximum_size=4194304
for a microcontroller with 4MB flash memory.

When boards are updated by the IDE or you uninstall and reinstall it, you will have to redo your changes.

Contributors are welcomed! If you want to submit pull requests, here is how you can do it.

Recommended IDE Setup The recommended IDE setup is Visual Studio Code + Vue - Official extension.

Project Setup

npm install

Compile and Hot-Reload for Development

npm run dev