docs/help/contents/custom-themes/using-themes.md
Notesnook keeps two themes at once — one for light mode and one for dark mode — and switches between them based on your color scheme. You can pick both from the built-in theme store, or load a theme from a theme.json file.
{{settings}}.{{customization}} → {{appearance}}.{{themes}}, set {{colorScheme}} to {{light}}, {{dark}} or {{auto}}.{{auto}} follows your operating system, so Notesnook flips with it.
::: tip Faster switching on desktop
The side menu profile menu has a {{toggleDarkLightMode}} item, so you don't have to open settings.
:::
Every theme in the store is fetched from themes-api.notesnook.com and installed on your device. The list only shows themes that are compatible with the version of Notesnook you're running.
{{settings}} → {{customization}} → {{appearance}}.{{selectTheme}}.{{searchThemes}} box to search, or use the {{all}}, {{dark}} and {{light}} filters to narrow the list.{{setAsDarkTheme}} / {{setAsLightTheme}} directly.A checkmark marks the themes you currently have applied.
There is no separate "which theme goes where" setting — a theme's own color scheme decides it. Applying a dark theme replaces your dark theme; applying a light theme replaces your light theme. Your {{colorScheme}} setting then decides which of the two you see.
So to have both: install a light theme, install a dark theme, and set {{colorScheme}} to {{auto}} (or {{useSystemTheme}} on mobile).
If you have a theme.json file — one you built with the Theme Builder, or one that isn't published yet — you can apply it directly.
{{loadFromFile}}..json file. Notesnook validates it and shows the theme's details.If the file is missing required fields or isn't a valid theme, the app tells you instead of applying it. Full steps and caveats are on install a theme from file.
The theme store is an open collection. Themes are submitted as JSON files to the notesnook-themes repository, and once merged they appear in the store for everyone. If you have made a theme you like, you can publish it the same way.
theme.json directly