I thought building browser-only image tools would mostly be about Canvas APIs and file formats.
It wasn’t.
The hard part started after tool #3, then tool #12, then tool #29: shared logic that wanted to fork, decoder libraries that were too expensive to load everywhere, export bugs that only showed up on transparent images, hash links that broke on real version IDs, and “fixed” assets that users still couldn’t see because cache visibility was treated as an afterthought.
For the past few weekends I’ve been shipping 24Picture, a free browser-local image toolkit. The stack is intentionally boring: static HTML, ES2020 JavaScript, Canvas, and a few route-specific decoders. No backend image processing. No uploads. Just a growing set of small tools that all need to feel consistent, stay fast, and survive hotfixes without turning into a pile of one-off exceptions.
Here are five patterns that actually held up.
