Built for agencies, not for everyone
Feature requests that pull SiteLetter toward monitoring for everybody get turned down. If you're an SRE running production, you'll be happier with Checkly.
About SiteLetter
About SiteLetter, the agency-first monitoring tool.
Built for web design and dev studios with a portfolio of client sites. The monthly client report is the product. The monitoring engine exists to feed it.
The deliverable, not a dashboard screenshot
What the product produces
Every monitored site produces a branded report on the schedule the agency chooses. Their logo, their accent color, their reply-to. The agency sends. SiteLetter does the work in the background.
- A White-label header Your agency's brand sits above the fold. SiteLetter's doesn't appear.
- B Plain-English score block Performance, Accessibility, Best Practices, SEO. Each with a trend vs the previous period.
- C Uptime with context Not just a percentage. The week, with the bad day visible.
- D Visual changes, AI-classified Cookie banner rotated? Auto-dismissed. Hero image missing? Flagged.
Plus SSL and domain expiry, broken-link sweep, and a portfolio overview across all client sites.
A
Acme Agency
Weekly Report · Apr 28 – May 4
Weekly Report
acme-client.com · 12 pages
Page Scores
Performance
Accessibility
Best Practices
SEO
Uptime
99.94% ↑ +0.03%
M
T
W
T
F
S
S
28
29
30
1
2
3
4
Visual Changes
Checked 8 pages - 1 meaningful change
/pricing Possibly broken
Hero image is missing on the pricing page - broken image placeholder visible.
/ Content update
Updated homepage hero copy and added a new testimonial card below the fold.
Every other monitoring tool was built for DevOps. Then a reports tab got bolted on
Most agencies run a Frankenstein stack. UptimeRobot pings the homepage. A Lighthouse runner spits out scores into a folder no one opens. A screenshot tool fires off cron jobs. And once a month, somebody on the team copy-pastes all of it into a Google Doc with the client's logo on top.
That document is the actual deliverable. It's what the retainer pays for. It's the one tangible artifact the client sees between the kickoff and the renewal call. Everything else is plumbing.
SiteLetter isn't trying to be the best fit for a fintech SRE team. It's trying to be the obvious choice for the studio that maintains thirty WordPress sites and bills a monthly retainer. See how it compares to Oh Dear, UptimeRobot, BetterStack, Checkly, and the rest.
What you can expect
Self-serve, end to end
Pricing is on the pricing page. The trial is self-serve. The contact form goes to a real person, who usually replies within one business day.
Honest about competitors
Every comparison page has a "where the other tool wins" section, with the strengths named. If a competitor is the better fit, the comparison page will tell you.
The boring details. Important anyway
- Hosted in
- AWS Stockholm EU · GDPR No data leaves the EU. Region eu-north-1.
- Pricing
- Flat $5 per site, per month All features included. 15 pages monitored per site.
- Trial
- 14 days, no credit card Full product. Add your first site. Reports go out for real.
- Founded
- Late April 2026 Sole-proprietor product. Funded by revenue, not investors.
- Cancellation
- Anytime, in-app Two clicks: cancel and confirm. No exit survey, no upsell.
- Data retention
- 2 years Uptime, Lighthouse, screenshots, and asset checks all kept for the same window.
- Support
- Email, usually within one business day For compliance or specifics, write to /contact.
- Run by
- Donatas Petrauskas Sole proprietorship (individuali veikla) in Lithuania.
Donatas Petrauskas
Founder · Lithuania
I've been a web developer for about ten years now.
I built SiteLetter because the gap in this category is sharp: most monitoring tools were built for SREs running production infrastructure, then had a "reports" tab bolted on later. The agency was a workaround. SiteLetter is the version where the agency is the customer.
SiteLetter started as a way to check whether my wife's site was up. Then I wanted Lighthouse on it. Then visual change detection. Then a weekly email so I'd stop refreshing the dashboard. The product spiraled out of that. I still run it on her site every day, and that's the first place a real bug surfaces.