Estimate any newsletter's subscribers and MRR. One click in Chrome.
Open any Substack, beehiiv, Mailerlite, or ConvertKit homepage. Click the extension. AI delivers a structured estimate — subscriber range, MRR range, growth rate, and sponsor outreach fit — with confidence levels and a rationale list. The analysis is the deliverable.
こんなお悩みありませんか？
- ✗No way to benchmark your own newsletter against direct competitors on Substack/beehiiv/Mailerlite
- ✗Sponsor teams have no data when picking which newsletter to advertise in
- ✗Substack's internal analytics only shows your own publication, not competitors
- ✗Operator tools like SparkLoop help you grow your own newsletter — they don't analyze rivals or build sponsor target lists
- ✗Manually browsing each homepage and guessing the metrics is not scalable
Install the extension. Open any newsletter. Receive the estimate as a finished output.
NewsletterLens is a Chrome extension that reads public signals (post cadence, comment counts, paid badge, archive depth) from any Substack, beehiiv, Mailerlite, or ConvertKit homepage. Claude Haiku turns those signals into estimated subscriber count, MRR, growth rate, and monetization mix — shown as ranges with confidence badges and rationale, never as point estimates. AI does the extraction and estimation; you make the outreach calls.
- 1
Install from Chrome Web Store
Add to Chrome in one click. No account required for the free tier (10 analyses/day).
- 2
Open any newsletter homepage
Visit a Substack, beehiiv, Mailerlite, or ConvertKit page. Click the extension icon.
- 3
Receive AI estimates as a deliverable
Subscriber range, MRR range, growth rate, and monetization mix — each with a confidence badge and rationale list. Read it, judge it, act on it.
- 4
Save to Watchlist & export
Save up to 100 newsletters to your Watchlist. Export the full sponsor target list as a CSV — that's the work product you take to outreach.
Cross-platform Chrome extension built for competitor analysis and sponsor sourcing
| 機能 | yoritech | 他社 |
|---|---|---|
| Cross-platform (Substack + beehiiv + Mailerlite + ConvertKit) | ✓ | SparkLoop covers operator growth on Substack/beehiiv only |
| We sell the CSV sponsor list and per-newsletter estimate as deliverables | ✓ | Dashboard SaaS sells access to a tool you have to drive yourself |
| Sponsor target list with CSV export | ✓ | Operator-side tools have no competitor or sponsor lookup |
| AI extracts and estimates, you decide the outreach | Confidence levels + rationale on every estimate | Manual homepage browsing — guesswork only |
| One-click in-browser flow (no login, no upload) | ✓ | Dashboard SaaS requires sign-up and URL submission |
パイロットプラン
ベータパートナー / Early Adopter 募集中。本リリース前の限定枠です。
Founder's Lifetime (Beta)
$49 one-time (first 100 only)
- ✓All Pro Annual features, forever
- ✓Limited to the first 100 Early Adopters
- ✓Beta feedback required (1 short survey/month)
- ✓Regular price will be $79/yr after launch
- ✓Lifetime lock-in — no future price hikes
Pro Beta
$4.5/mo (50% off, beta period only)
- ✓100 URL analyses per month
- ✓Watchlist up to 100 newsletters
- ✓Sponsor target list CSV export
- ✓Reverts to $9/mo at GA release
- ✓Direct Slack/email line to the founder
Billed in USD via ExtensionPay (Stripe). You're paying for the analysis outputs and the CSV sponsor list — not for time-based access to a dashboard. Cancel anytime from the extension popup.
よくある質問
- Q. How accurate are the estimates?
- We aim for ±40% accuracy on subscriber and MRR estimates, with the early version landing within ±50%. Every estimate ships as a range with a confidence badge (high/mid/low) and a rationale list of the public signals used. We never sell point estimates.
- Q. Is this scraping? Is it allowed?
- We only read public homepage content as an extension of your own browsing — one page per click, no automated crawling, no access to logged-in or private areas. We respect robots.txt. If a platform notifies us of a ToS concern, the affected functionality is disabled within 48 hours.
- Q. Which platforms are supported?
- Substack, beehiiv, Mailerlite, and ConvertKit public homepages. Cross-platform support is the core of the product — we will not ship a Substack-only build.
- Q. How is the sponsor target list generated?
- Tell the extension your own newsletter's topic and audience. The AI matches Watchlisted newsletters by brand fit and audience overlap, scoring each as a sponsor candidate. Export as CSV for outreach.
- Q. What happens to my data if I cancel?
- Your Watchlist and analysis history are stored locally in the browser (IndexedDB). Canceling Pro reverts you to the free tier — your data stays intact. You can clear it anytime from the extension settings or export to CSV first.
- Q. Do you offer team or enterprise plans?
- Yes. The Team plan includes up to 5 seats and a shared Watchlist for $29/mo. For larger newsletter agencies, contact us via the main site for custom seat counts and invoicing.
- Q. Is there an API?
- Not yet. The Chrome extension is the primary interface. A REST API is on the 2026+ roadmap for agency customers who need bulk analysis.