CarsonJ

I kept seeing those "smash two emojis together" sites and noticed something: most of them upload your image to a server. Even when the math is just stacking pixels.

So I built my own. It runs entirely in the browser. No uploads, no signup, no paywall.

Here's how it works:

  • Pick up to 4 emojis from a searchable grid
  • The tool uses the Unicode emoji list and renders each one to a canvas
  • It composites them with offset, scaling, and rotation
  • You get one PNG to download

The whole thing is about 200 lines of JavaScript. No backend. No API. No tracking. The emoji data ships with the page.

If you want to see it: https://korelyy.com/en/tool/emoji-mixer/

A few things I learned while building it:

1. Most "client-side" tools still hit a server. The hidden cost is usually analytics, asset CDN, or auth. Real client-side means the page works offline after first load.

2. Canvas compositing has hidden gotchas. Emoji rendering across platforms gives different base images. Apple's cat emoji is not the same as Google's. I default to the system font the user already has, so the result feels native.

3. The fun tools spread faster than the useful ones. My calculator for container shipping has solid keyword potential. The emoji mixer gets 10x the social shares. Build accordingly.

4. Browser-only also means privacy by default. A user pasting sensitive content into a "redact PDF" tool shouldn't have to trust the server. Local-only removes that question entirely.

I have about 50 small tools like this on my site now. Each one is the answer to a "I just need to do X real quick" moment. Some get used once a day, some once a year. Both are worth building if the alternative is opening an app and signing up.

If you want to see the full set: https://korelyy.com/en/

The video showing it in action: https://www.youtube.com/shorts/riFG3Jq8-7c

What's a "quick task" tool you wish existed but you keep avoiding because it needs a login?