How to build a Chrome extension that earns $4.7K/mo using Claude
A 200-line Chrome extension wrapping Claude — sold for $9/mo.
- 1.Built a Chrome extension that summarizes any webpage with Claude in one click.
- 2.Free tier (3 summaries/day) → Pro at $9/mo (unlimited + custom prompts).
- 3.Hit $4.7K MRR by month 3 with 520 paying users. Solo dev, nights and weekends.
The story
The product is brutally simple: highlight text on any page → click extension icon → get a Claude-generated summary, action items, or translation. That's it.
What worked was the distribution. Chrome Web Store has built-in search demand for "summarize" and "AI reader" — 80% of installs came from organic store search, not paid ads.
Conversion to Pro happens when free users hit the daily limit. The cap is intentional friction, not a bug. ~7% of weekly active free users convert.
The exact stack
Tools they used. Click any to start with the same setup. Total cost: ~$155/mo at 520 paying users
The playbook
Pick a single, obvious workflow
Don't build "an AI assistant." Build "summarize this page in 3 bullets." One job, done in one click.
Use Claude Haiku for cost
Haiku is 10x cheaper than Sonnet and easily good enough for summarization. Cost-per-user must be under $0.50/mo for a $9/mo product to work.
Optimize the Chrome Web Store listing
Title, screenshots, and the first 100 chars of description determine 90% of installs. Use the OneClickTool /listing-chrome workflow.
Free tier with hard daily limit
Limits create urgency. Free tier of 3/day converts ~7% to Pro. Generous free tiers (unlimited) convert under 1%.
Use a merchant-of-record for billing
Lemon Squeezy handles VAT/sales tax globally. Critical when 60% of your users are outside the US — saves 20 hours/mo of accounting headaches.
Revenue breakdown
- →Chrome Web Store is an underrated distribution channel for Claude wrappers.
- →Haiku, not Sonnet, is the right model for high-volume B2C use cases.
- →Hard limits in free tiers convert 7-10x better than soft suggestions.