Real User Monitoring

Catch slowdowns in minutes, not days – before they cost you rankings or conversions

Lab testing only tells part of the story. RUM captures performance data from every real visitor, revealing the actual experience across different devices, browsers, networks, and geographic locations. Every visit reports back, so a bad deploy shows up in your data long before it shows up in your search rankings.

All Core Web Vitals
Device & Browser Segmentation
Geographic Performance
Page-Level Insights

Start Monitoring Free View Pricing

Want a one-off check first? Run the free CrUX History – no signup, and your results are never kept.

RUM MonitoringCritical

▸ MOBILE

LCP

4.3s▲34%

CLS

0.06

INP

410ms

TTFB

1.4s

ERRORS

2.4%▲1.1%

▸ DESKTOP

LCP

1.4s▼2%

CLS

0.01

INP

90ms

TTFB

1.2s

ERRORS

1.1%▲0.4%

75th percentile · Last 7 days128,540 visits

// the problem

Lab tests look great, but users are complaining

Your Lighthouse score is 95+, yet users on mobile networks are bouncing. Lab tests run in controlled conditions – real users don't have that luxury.

Your 3G users in Southeast Asia have a completely different experience than your lab tests suggest

Performance regressions slip into production and go unnoticed for days

You can't reproduce the slow performance users are reporting

Google's Core Web Vitals assessment uses field data, not your lab tests

Third-party scripts behave differently in production than in testing

You're making optimization decisions based on incomplete data

// what you can monitor

All your Core Web Vitals in one place

Track LCP, CLS, INP, FCP, and TTFB from real users. See trends, segment by device and location, and identify performance issues quickly.

01

All Core Web Vitals

Track every metric that matters: LCP (Largest Contentful Paint), INP (Interaction to Next Paint), CLS (Cumulative Layout Shift), FCP (First Contentful Paint), and TTFB (Time to First Byte). LCP, INP, and CLS are the three Core Web Vitals Google evaluates; FCP and TTFB help you diagnose why they slip.

02

Device & Browser Segmentation

Break down performance by device (mobile and desktop) and browser (Chrome, Safari, Firefox, Edge). Identify which combinations cause issues.

03

Geographic Performance

See how performance varies by country. Find out whether slow CDN nodes or regional network issues are affecting specific user groups.

04

Page-Level Insights

Don't settle for site-wide averages. Drill down to individual pages to find specific bottlenecks. Your checkout page might be fast while your product pages suffer.

05

JavaScript Error Tracking

Beyond performance, RUM captures JavaScript errors and failed resource loads from real sessions. See which errors affect the most visitors, with stack traces, browser, and page context to help you reproduce and fix them.

06

Historical Trends & Comparisons

Track performance over time with up to 24 months of data retention. Compare periods to measure the impact of deployments, optimizations, or third-party changes.

07

Percentile Distribution

See the full picture with the 75th percentile – the same standard Google uses for Core Web Vitals assessment. Understand how 75% of your users experience your site.

08

Session-Level Analysis

Drill into individual page views, each with its own Core Web Vitals and timing detail. See the device, browser, operating system, and network conditions behind every slow page view, plus the resources it loaded.

09

Engagement Correlation

See how performance impacts user behavior. Correlate Core Web Vitals with scroll depth, bounce rate, clicks per session, and time on page to understand the real cost of slow performance.

// field data by device

See what mobile visitors actually feel

Break down every Core Web Vital by device and browser at the 75th percentile, the same percentile Google uses to assess your site. Field data from mobile users on slower networks often tells a very different story than your desktop lab tests do.

LCP, INP, CLS, FCP, and TTFB at the 75th percentile
Segment by device (mobile and desktop) and browser
Spot the device and browser combinations dragging your metrics down

Core Web Vitals – Mobile75th percentile

LCP

4100 ms

Poor

INP

340 ms

Needs improvement

CLS

0.04

Good

TTFB

1400 ms

Needs improvement

// no sampling, every visit

Data from every real visit, in minutes

Drop in one lightweight script and real users start sending Core Web Vitals within minutes. By default there is no sampling, so every page view counts – not a filtered slice of your traffic.

One ~13KB script that works with any framework or CMS
No sampling by default – every page view within your plan's quota is captured
Real users start sending data within minutes

Live page viewsLive

PAGE VIEWS TODAY

48,210

Streaming liveNo sampling

// trends and regressions

Catch regressions before revenue drops

Track each Core Web Vital over time to measure the impact of deployments and third-party changes. When a metric slips after a release, you see it within minutes – not days later when your search rankings react.

Compare periods to measure the impact of deployments
Up to 24 months of history for every metric
Alerts on every Core Web Vital, based on the last 24 hours

LCP trendMonitoring

Last 7 daysGood < 2500 ms

LCP · 75TH PERCENTILE

2400 ms

UpdatingUp to 24 months

Start collecting real user data in minutes

1Step 01

Add a lightweight script to your site

Copy and paste a single script tag into your HTML. At ~13KB gzipped, it won't impact your page performance. Works with any framework or CMS.

2Step 02

Real users start sending data within minutes

As visitors browse your site, their Core Web Vitals are collected and sent to VitalSentinel. By default there's no sampling – you get data from every page view, up to your plan's monthly page-view limit.

3Step 03

Analyze, segment, and compare

Use the dashboard to slice data by device, browser, location, and more. Set up alerts for performance regressions. Track improvements over time.

4Step 04

Get alerts when issues arise

Configure thresholds for each Core Web Vital. When real users start experiencing problems, you'll get an alert – long before it shows up in your search rankings.

// in the real world

Real scenarios, real fixes

E-commerce sites

Challenge

"Conversion rates are down but you can't figure out why. Lab tests look fine."

Solution

RUM reveals that mobile users on slower connections are experiencing 4+ second LCP times, causing them to abandon before checkout loads.

Content publishers

Challenge

"Google Search Console shows failing Core Web Vitals but you can't reproduce the issue."

Solution

RUM data shows which specific pages and user segments are failing, letting you prioritize fixes that will actually make a difference.

Development teams

Challenge

"After a deployment, users complain about slowness but your monitoring shows green."

Solution

RUM catches the regression within minutes, showing exactly which metric degraded and on which pages, so you can ship a fix before more users are affected.

// pairs well with