BuildMe
4–6 hoursAdvanced

Build a Chrome Extension That Fixes Your Pet Peeve

Maps to: Software Engineer · Product Designer, Founder

You're going to build a Chrome extension that fixes something on the web that annoys you every day (a cluttered feed, endless threads, a site that buries what you need) and get it running in real browsers. The skill is subtraction: testing on the real sites, then cutting it to the one behavior actually worth keeping and making that solid. That's real software engineering, shipping code that runs in other people's browsers and doing one thing well, and doing one tells you fast whether building tools that run in the wild is your kind of work.

The plan

0/4 done

You're 20% in just for starting, the hardest part. Mark your first step done to keep the momentum.

  1. Pick one real thing that bugs you in the browser: cleaning up a feed, summarizing long threads, limiting time on an app, reformatting a site you use daily. Write what the extension does in one line. That's your target.

    Objective: A chosen annoyance and a one-line description of the fix.

    1. 1

      Pick the annoyance you'd actually use a fix for every day. Personal beats clever.

    2. 2

      Write the one behavior the extension adds, in a sentence.

    Your call

    Choose the annoyance yourself (clean a feed, summarize threads, track-limit time, or reformat a site) and the one behavior the fix adds.

    The annoyance, and the one behavior the extension adds.

    What good looks like: Your one line names a behavior so specific you'd know the moment the extension works, or doesn't.

    • Pick something you hit daily. You'll be your own best tester.

The bar to look back against

An extension that works on real sites, installed by a few real people (sideloaded or published), cut to the one behavior worth keeping. The subtraction is the work: not 'it loaded,' but 'it actually fixes the annoyance, on real sites, for real people.'

Finish the final step, then submit what you built. Your progress is saved.

Tools you'll use

Steps 2–4 · Build it (start from a working example)

Cursor Free

An AI code editor (the Hobby plan is free, no card).

Best for: Writing the extension with AI help. (Free Hobby: limited agent + completions.)

VS Code Free

The free, standard code editor.

Best for: If you'd rather not use an AI editor.

Chrome Extensions docs (Manifest V3) Free

Google's official guide + the manifest format.

Best for: Your reference: start from a working sample and change one thing.

Step 6 · Ship it: sideload to friends (or publish)

Chrome Web Store (publish) Paid

Publishing to the store (one-time $5 developer registration fee).

Best for: The UPGRADE, to publish publicly. Free path: sideload the unpacked extension (no fee, no card).

How this shows up on a resume or college app

I built a Chrome extension that solves [problem], cut it to the one behavior worth keeping after testing on real sites, and got it installed by [N] people. I learned to ship software that runs in real users' browsers every day, and that the discipline is subtraction, not addition.