Website Health, Delivered by Email
Agency-grade monitoring for Visuals, Performance, and Site Health. Get alerts & weekly reports without the dashboard fatigue.
No credit card required.
Visual Comparison
This email was sent by SiteLetter.
Comprehensive coverage
We monitor the things that actually impact your client's revenue and reputation.
Lighthouse Performance
We run full Lighthouse audits on a schedule. Track Performance, Accessibility, Best Practices, and SEO scores over time.
- Core Web Vitals tracking
- Desktop viewport analysis
- Performance, SEO, Accessibility & Best Practices
- Historical score trends
Hygiene Checks
Don't let an expired certificate or 404 page embarrass you in front of a client.
Visual Regression
Catch UI bugs before your client does
We take pixel-perfect screenshots of your critical pages and compare them to a baseline. If a button disappears or a layout breaks, you'll see exactly what changed.
Baseline
Current
How it works
No code snippets. No DNS changes. No agents to install.
Add your website
Enter a URL and your email address. We validate the domain and start the first scan within minutes.
- Any public website or subdomain
- Specific paths supported
- Auto sitemap discovery
Automated monitoring
Our servers run audits, capture screenshots, and check infrastructure health on a fixed schedule.
- Performance, SEO, Accessibility
- Pixel-level visual comparison
- SSL, domain, broken links
Reports in your inbox
Receive a structured email with scores, diffs, and status checks. Act on issues directly — no login needed.
- Weekly summary reports
- Instant alerts on regressions
- White-label reports for clients
Simple, transparent pricing
Start for free, upgrade when you need more power.
Free
Perfect for personal projects.
Pro
For freelancers and pros.
Agency
For agencies managing multiple clients.
Need more? Let's talk.
Frequently asked questions
Everything you need to know about SiteLetter and how it works.
No. SiteLetter runs entirely from our servers. You just provide the URL, and we handle the monitoring externally. This means zero impact on your site's performance.
We run Lighthouse and visual regression scans daily (or weekly on the Free plan). SSL, domain expiry, and broken link checks run daily to catch issues before they affect your visitors.
Yes. On the Agency plan, you can remove our branding, add your own logo, and even customize the colors to match your brand identity before sending them to clients.
We take a screenshot of your site's key pages and compare them to a 'baseline' version. If a pixel changes (e.g., a button moves, or CSS breaks), we highlight the exact difference so you can fix it before users notice.
Absolutely. There are no long-term contracts. You can upgrade, downgrade, or cancel your subscription at any time from your dashboard.
Currently, we only monitor public-facing pages. We are working on support for Basic Auth and custom headers for staging environments in the future.
Still have questions? Contact support
Start monitoring in 30 seconds
No credit card required. No scripts to install.
Just enter your URL and we'll do the rest.
Cancel anytime. No lock-in.