For Web Developers
See what your users actually experience, not just what your Lighthouse score says
Your Lighthouse score is 95, but users are complaining about slow performance. Sound familiar? VitalSentinel gives you real user monitoring data alongside synthetic testing, so you can see what's actually happening in production, catch regressions in real user data, and prove that your optimizations work.
Lab tests pass. Real users have a different experience
Lighthouse runs in an ideal environment. Your users don't. They're on slow networks, old devices, and across the world from your servers.
Lab testing shows perfect scores, but real users report completely different experiences
You can't reproduce the performance issues users are complaining about
It's impossible to tell if your optimizations actually made a difference in production
Performance regressions ship to production and go unnoticed for days or weeks
You don't know which specific pages, devices, or countries are having problems
Without production data, you're optimizing blind
What you get with VitalSentinel
Debug faster with production data
Stop trying to reproduce issues locally. See exactly what happened for the users who complained, with full device and network context.
Catch regressions in real user data
See when a deployment hurts performance in real user data. Roll back or ship a fix before it affects more users.
Prove your optimizations work
Show stakeholders real data proving that your performance work delivered measurable improvements in production, not just lab scores.
Prioritize with confidence
Focus optimization efforts on the pages, devices, and countries that actually matter for your users.
See what your deploy did to Core Web Vitals
Compare Core Web Vitals before and after a release, straight from real users. Spot at a glance whether a deployment pushed LCP, INP, or CLS past acceptable levels – no need to reproduce it locally.
- Real user LCP, INP, and CLS from production
- Before and after comparison on every release
- Catch a bad change before it slips by unnoticed
Watch an LCP regression the moment it ships
A fresh bar lands as real user data streams in, so you see LCP climb right after a release instead of days later. Roll back or hotfix while it still affects only a fraction of users.
- Live real user LCP, updating continuously
- Regressions surface within minutes of a deploy
- Roll back before it reaches more users
Get alerted when a Core Web Vital crosses your threshold
Set thresholds for your Core Web Vitals and VitalSentinel alerts you when real user data crosses them. Drill into the exact device, page, or country behind the drop.
- Threshold alerts on Core Web Vitals
- Shows when your 75th percentile crossed the threshold
- Drill down by device, page, or country
A perfect lab score that hides a real problem
Scheduled Lighthouse tests give you a clean, repeatable lab score across Performance, Accessibility, Best Practices, and SEO. Set it next to real user monitoring and you can see exactly where a green lab result and a slow visitor part ways.
- Scheduled Lighthouse tests on every key page
- Performance, Accessibility, Best Practices, and SEO scores
- A repeatable lab baseline to compare against real users
Lab conditions look great. Pair this with real user data and you catch the gap between a passing test and what visitors actually experience.
Every module you need, in one place
Six monitors and two analytics – on every plan, in a single dashboard.
How developers use VitalSentinel
Add the RUM script
A single lightweight script (~13KB) captures Core Web Vitals from real users. Works with any framework. Takes minutes to integrate.
Set up synthetic monitoring
Configure scheduled Lighthouse tests for your key pages. Choose the test frequency and locations. Results are stored automatically.
Set performance thresholds
Define acceptable ranges for Core Web Vitals. Get alerts when metrics exceed thresholds so you can catch regressions quickly.
Debug with real data
When issues arise, drill down by device, browser, country, or page. Find the root cause with actual production data, not guesswork.
Every module included. You only choose your coverage
All plans include all eight modules. Start free, upgrade only when you need wider coverage.
Starter
For small businesses and personal projects
- 3 domains
- 100K RUM page views/mo
- 1M analytics events/mo
- 12 months data retention
Lite
For consultants and growing businesses
- 5 domains
- 250K RUM page views/mo
- 5M analytics events/mo
- 16 months data retention
Stop guessing. Start measuring.
Get production performance data alongside lab testing. Debug faster, ship with confidence.