I built a tiny animated cat companion for Chromium tabs :3

KOUSTAV ROY — Tue, 18 Aug 2026 01:33:12 +0000

I wanted my browser tabs to feel a little less empty, so I made Mochi.
Mochi is a small Chromium extension that places an animated cat directly on your browser tabs. You can choose from 20 cat styles, drag the cat anywhere on the page, and keep it in the same spot while switching between tabs.
It is not a productivity tool, tracker, or notification machine. It is intentionally small and quiet—just a little companion while you browse, work, study, or watch videos.
What it does
Includes 20 animated cat styles
Lets you drag the cat anywhere on the page
Keeps the cat’s position synchronized across tabs
Supports show, hide, and pause controls
Uses a simple local-first setup
Requires no account and includes no ads or analytics
A little about how it works
Mochi is built with plain HTML, CSS, and JavaScript using Manifest V3. The popup handles the controls, the background service worker manages shared state, and the content script renders the cat on the page.
The shared state stores the selected cat style, position, visibility, and pause status. When something changes in one tab, the other tabs receive the update and stay in sync. The cat also uses an isolated class name and fixed sizing so random website styles do not resize it.
The project started as a silly little side quest and slowly became a proper extension. I kept the scope intentionally small because sometimes a project does not need to solve a huge problem. Sometimes it can just put a cat in your browser.
You can try it or look through the code here:
GitHub: https://github.com/koustavdatascience/mochi
I’d love feedback on the extension, the UI, the installation flow, or anything that could be cleaner.

DEV Community: KOUSTAV ROY

I built a tiny animated cat companion for Chromium tabs :3