26 Jun 2026 4 min
I deleted the theme toggle, then put it back
The case against a manual dark mode is strong, obvious, and slightly wrong.
For about six months this site had no way to change its appearance. It read your system setting and did as it was told, which is the correct default and the advice I would still give anyone shipping a product. A toggle is a preference you now have to store, sync, reconcile with the operating system, and explain when it disagrees with the operating system.
The argument for deleting it
Every toggle is a small contract. You are promising to remember the choice, to honour it on the next visit, and to not surprise the person when their laptop switches to dark at sunset and your site does not. Most sites break at least one clause of that contract. Mine did: the setting lived in memory and evaporated on reload, which is worse than not offering it at all.
So I removed it, and for six months nobody complained, because nobody complains about a website. That is not evidence of anything.
The argument for putting it back
What changed my mind was watching someone read one of these posts on a train. Their phone was in light mode because the OS had decided, from the ambient sensor, that a bright carriage called for it. They were squinting. They had no way to tell my site that the sensor was wrong.
The system setting is a good guess about the room. It is a bad guess about the moment. A reader on a night train, a designer checking a palette, someone with a migraine at two in the afternoon — all of them know something the sensor does not, and a site with no switch tells them their knowledge is inadmissible.
How I put it back
Three rules made it honest. The choice is written to storage before anything paints, so there is no flash of the wrong theme on the next load. An untouched site still follows the system, so the default costs nothing. And the control is a single glyph in the corner — no menu, no third option called auto, because a third option is a confession that the first two are not trustworthy.
It is also, I admit, the only piece of delight on the whole site. The disc turns. I have watched people press it four or five times in a row and then read the post anyway.