When building a long survey in the KoboToolbox Form Builder, I started noticing that the editor becomes very slow after adding several repeat groups and nested questions. At first everything worked normally, but once the form grew larger, every edit began taking several seconds to respond. Sometimes the page freezes briefly before becoming usable again.
Another issue is that changes made to question labels or relevance conditions occasionally do not appear to save correctly. I can click Save, and there are no visible errors, but after refreshing the page, some of the recent edits are missing. This does not happen every time, which makes it difficult to reproduce consistently.
I also noticed that opening repeat groups or moving questions within the form takes much longer than expected. Dragging and dropping questions sometimes causes the interface to become unresponsive for a short period. My browser does not crash, but the editing experience becomes frustrating on larger forms.
To rule out local issues, I tested the same project in both Google Chrome and Mozilla Firefox with all extensions disabled. I cleared the browser cache and even tried using a different computer, but the behavior remained the same. My internet connection is stable, and smaller forms work without any noticeable delays.
The form contains many skip logic rules, calculations, and repeat groups because it is designed for field data collection. I am wondering if there is a recommended limit for the number of questions or nested repeats in the online Form Builder. If so, is XLSForm a better option for managing complex forms of this size?
Has anyone else experienced slow performance and inconsistent saving when working with large KoboToolbox forms? I would appreciate any suggestions for improving the editor’s responsiveness or identifying whether this could be related to a known limitation or configuration issue. Any troubleshooting steps or best practices would be very helpful. Sorry for long post!
