# Web demo crashes upon selecting "Custom HTML" interface
**URL:** \
**Category:** Uncategorized\
**Tags:** docs, done\
**Created:** [January 10, 2020, 7:14pm UTC](https://support.prodi.gy/t/web-demo-crashes-upon-selecting-custom-html-interface/2414 "2020-01-10T19:14:29Z")\
**Posts on this page:** 1\
**Showing post:** 4
**Author:**  [@ines](https://support.prodi.gy/u/ines)\
**Post date:** [July 29, 2020, 4:22pm UTC](https://support.prodi.gy/t/web-demo-crashes-upon-selecting-custom-html-interface/2414/4 "2020-07-29T16:22:21Z")
Glad you like the demo 😊
> [@DROMZEE](#):
>
> I want to change it to add a user interface language selection
The live demo is just a demo and it doesn't actually run a recipe – it just serves static content from custom, pre-defined API endpoints. It also adds the dropdowns that just discard everything and reload the app, which is nice for a demo, but doesn't really make much sense in a "real world" application. I'm explaining a bit more about this here:
> [@live demo like user interface](https://support.prodi.gy/t/live-demo-like-user-interface/1039/2):
>
> Hi! Here are two threads where I explain a few more details on why Prodigy is designed to use separate processes for different tasks and why switching between different streams and interfaces in the browser like that only really works for a demo: [https://support.prodi.gy/t/multiple-recipes-same-port/933/2](https://support.prodi.gy/t/multiple-recipes-same-port/933/2) That said, if you're mostly interested in having a quick way to start a different task from the browser without having to go back to the command line, you could write a mini app that lets t…
The UI language is typically set in the config on startup so there's not really a built-in way to change it at runtime, although it could be possible. (I haven't tried this yet, but one option would be to update the config of the current annotation task to overwrite it on a per-task basis – like: `window.prodigy.update({ config: { ui_lang: 'fr' }})`. But now sure how that behaves, it might switch back when the next task is loaded.)
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_[View the full topic](https://support.prodi.gy/t/web-demo-crashes-upon-selecting-custom-html-interface/2414)._