Public BetaVitalSentinel is now live! Read the announcement

For Web Developers

Debug with real user data, not just lab tests

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 immediately, and prove that your optimizations work.

Your Command Center

Everything in one dashboard

Stop jumping between tools. See your entire website health at a glance.

app.vitalsentinel.com/dashboard/domains/example.com

example.com

30-Day Overview

RUM
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LCP1.8sCLS0.04INP142msTTFB285ms
LCP1.4sCLS0.02INP68msTTFB195ms
CrUX
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LCP2.1s↓4.5%CLS0.05INP245ms↑8.2%TTFB412ms↑3.1%
LCP1.3s↓12.4%CLS0.01INP52ms↓5.8%TTFB287ms↓7.3%
Synthetic
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LCP4.2sCLS0.02TTFB189msRequests87
LCP1.6sCLS0.01TTFB156msRequests94
Uptime
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UP99.94%SSL: 83 daysDomain: 247 days
Robots.txt
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No errorsLast checked: 12 minutes ago
Google Search Console
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Web:38.4Kclicks↑12.3%1.2Mimpressions↑8.7%3.2%CTR↑3.3%
Discover:8.7Kclicks↑24.1%285Kimpressions↑18.5%3.1%CTR↑4.7%
News:1.2Kclicks↓5.2%24.8Kimpressions↓2.8%4.8%CTR↓2.5%
Google Analytics
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118.2K users254.7K sessions ↑9.4%63% engaged ↑4.2%
Web Analytics
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124.6K visitors267.8K views38.2% bounce2m 18s avg

Lab tests pass. Production users are having 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.

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Lab testing shows perfect scores, but real users report completely different experiences

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You can't reproduce the performance issues users are complaining about

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It's impossible to tell if your optimizations actually made a difference in production

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Performance regressions ship to production and go unnoticed for days or weeks

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You don't know which specific pages, devices, or regions are having problems

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Without production data, you're optimizing blind

How We Help

Solutions for your daily challenges

Real User Monitoring (RUM)

Capture Core Web Vitals from every real visitor. See actual LCP, INP, CLS, and other metrics from production - not just lab conditions.

Deployment Tracking

Compare performance before and after deployments. See immediately if a release caused a regression. Correlate performance changes with specific commits.

Segmentation & Filtering

Drill down by device type, browser, network connection, geographic region, or specific pages. Find exactly where and why performance is degraded.

Synthetic + RUM Together

Run scheduled Lighthouse tests alongside real user data. Understand when lab results don't match production reality and investigate why.

Percentile Distribution

Your median might look fine while your p75 users have a terrible experience. See the full distribution to understand your worst-case scenarios.

Automated Regression Alerts

Get notified when performance degrades after deployments. Set thresholds for Core Web Vitals and get alerts when metrics exceed acceptable levels.

Benefits

Why teams choose 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 immediately

Know within hours - not weeks - when a deployment impacts performance. Roll back quickly or hotfix 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 regions that actually matter for your users. Data-driven prioritization.

Quick Setup

How developers use VitalSentinel

1

Add the RUM script

A single lightweight script (~11KB) captures Core Web Vitals from real users. Works with any framework. Takes minutes to integrate.

2

Set up synthetic monitoring

Configure scheduled Lighthouse tests for your key pages. Choose frequency and geographic locations. Results are stored automatically.

3

Set performance thresholds

Define acceptable ranges for Core Web Vitals. Get alerts when metrics exceed thresholds so you can catch regressions quickly.

4

Debug with real data

When issues arise, drill down by any dimension. Find the root cause with actual production data, not guesswork.

Total setup time: ~5 minutes
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Free plan availableNo credit card requiredSetup in under 5 minutes

Stop guessing. Start measuring.

Get production performance data alongside lab testing. Debug faster, ship with confidence.

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