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Data collected in Real User Monitoring (RUM)

This document outlines all the key data fields collected by Site24x7's RUM.

Each data point helps you analyze performance bottlenecks, diagnose issues quickly, and optimize the user experience across different browsers, devices, and network conditions.

Use this reference to understand what information is being collected, where it comes from, and how it contributes to your monitoring insights.

User Session data

Field Description Source Reference link
uid The custom userId set via an API Custom API Custom API: userId
guid The auto-generated userId used if the uid is not set Site24x7 -
session_id The auto-generated session ID stored in cookies to identify unique users and sessions Cookie Session data collection
ip The captured origin IP address used to extract geolocation data (IP data is not stored by default; it can be stored by enabling IP configuration) X-Forwarded-For header X-Forwarded-For

Geolocation data

Field Description Source
country The country derived from the IP address IP geolocation
region The region derived from the IP address
city The city derived from the IP address
isp The ISP derived from the IP address

Environment data

Field Description Source Reference link
device_view_port Calculated from the browser window dimensions window.screen Window Screen API
devicememory The user’s device memory navigator.deviceMemory Device Memory API
device_connection The user’s network connection type navigator.connection.effectiveType Connection type
device The user's device type User agent -
browser The browser name User agent -
browser_version The browser version User agent -
bot The identification of the bot or crawler User agent -
environment The custom environment set via an API Custom API Custom API: environment

Transaction data

Field Description Source
txn The path and query of the current page document.location and window.location
full_txn The complete page URL
domain The origin of the current URL (the protocol and hostname) window.location.origin
http_status The HTTP status of the network request Fetch or XHR API response

Error data

Field Description Source
file The script file where the error originated window.onerror and window.onunhandledrejection
url The full URL of the error's source file
type The error type (e.g., TypeError or PromiseRejectionEvent)
message The error message describing the issue
function The name of the function where the error occurred
line The line number in the script file where the error occurred
column The column number in the script file where the error occurred
trace The call stack at the point where the error occurred
user_trace The breadcrumb trail of user events leading to the error (e.g., events like click and load) DOM events

Web Vitals data

Field Description Source
lcp_element The largest contentful element in the viewport PerformanceObserver (largest-contentful-paint entry)
cls_element The element that caused the highest layout shift PerformanceObserver (layout-shift entry)
fid_element The first interacted element causing the input delay PerformanceObserver (first-input entry)
fid_event The event type triggering the first input delay PerformanceObserver (first-input entry)
inp_element The element interacted with for Interaction to Next Paint measurement PerformanceObserver (event-timing entry with interactionId)
lcp Largest Contentful Paint: The time it takes for the largest content element to become visible in the viewport PerformanceObserver (largest-contentful-paint entry's startTime + renderTime)
cls Cumulative Layout Shift: The score representing the total of all unexpected layout shifts that occur during the entire lifespan of a page PerformanceObserver (layout-shift entries' cumulative value)
fcp First Contentful Paint: The time it takes for the first piece of content (text, image, canvas, etc.) to appear on the screen PerformanceObserver (paint entry with the name as first-contentful-paint)
fid First input delay: The time from when a user first interacts with a page (e.g., clicks a button) to the time when the browser is actually able to begin processing event handlers in response to that interaction PerformanceObserver (first-input entry's processingStart - startTime)
inp Interaction to Next Paint: The metric that assesses the overall responsiveness of a page to user interactions by looking at the latency of all discrete user interactions that occur throughout the lifespan of a page PerformanceObserver (event-timing entries with interactionId)
ttfb Time to First Byte: The time elapsed from the user initiating the request for a document to the first byte of the response arriving PerformanceObserver (navigation entry's responseStart - requestStart)

Performance metrics data

Field Description Source
used_heap_memory The amount of memory currently being used by the JavaScript heap window.performance.memory.usedJSHeapSize
free_heap_memory The estimated amount of free memory available in the JavaScript heap  (window.performance.memory.totalJSHeapSize - window.performance.memory.usedJSHeapSize)
rdt Redirect time: The time taken for all redirects to be completed window.performance.timing calculated as redirectEnd - redirectStart
dnst DNS lookup time: The time taken to perform DNS resolution for the main document window.performance.timing calculated as domainLookupEnd - domainLookupStart
cont TCP connection time: The time taken to establish a TCP connection to the server window.performance.timing calculated as connectEnd - connectStart
dlt Download time: The amount of time it takes to download the requested content window.performance.timing calculated as responseEnd - responseStart
drt Document rendering time: The amount of time taken by the browser to parse the HTML and render the DOM tree window.performance.timing calculated as domComplete - domLoading
prt Page rendering time: The time taken to execute any additional logic after the page has finished loading window.performance.timing calculated as loadEventEnd - loadEventStart
fbt First byte time: The amount of time taken by the browser to receive the first piece of information for a request window.performance.timing calculated as responseStart - redirectStart
nwt Network time: The sum of the redirect time + DNS lookup time + TCP connection time + download time window.performance.timing
bet Back-end or server time: The amount of time taken by the application back end to serve the requested resource window.performance.timing calculated as responseStart - requestStart
fet Front-end time: The sum of the document rendering time + page rendering time window.performance.timing
totalRT Total response time: The sum of the network time + back-end or server time + front-end time window.performance.timing
totalSZ Total size: The estimated total size related to the resource Calculated based on document.documentElement.innerHTML.length (for the main document) and the PerformanceResourceTiming entry (transferSize)
name The URL of the resource being loaded PerformanceResourceTiming entry
initiator The type of element or process that initiated the resource request (e.g., link, script, img, or fetch)
extension The file extension of the resource (derived from the name) Derived from the PerformanceResourceTiming entry name
cross_domain The Boolean expression indicating whether the resource was loaded from a different origin Derived from comparing the origin of the resource name with window.location.host
cached The Boolean expression indicating whether the resource was retrieved from the browser's cache PerformanceResourceTiming entry (transferSize is 0 or encodedBodySize is 0 and decodedBodySize is greater than 0)
duration The total time taken to load the resource, from the start of the request to the end of the response PerformanceResourceTiming entry
blocked The time the request was blocked before it could be sent PerformanceResourceTiming entry calculated as requestStart - connectEnd or domainLookupStart - fetchStart
sslt SSL/TLS negotiation time: The time taken to perform the SSL/TLS handshake PerformanceResourceTiming entry calculated as connectEnd - secureConnectionStart
size The size of the downloaded resource PerformanceResourceTiming entry (encodedBodySize)
ratio Compression ratio: The ratio of the encoded size to the decoded size of the resource (if compression was used) Derived from PerformanceResourceTiming entry (encodedBodySize / decodedBodySize)
start_time The time at which the browser started fetching the resource PerformanceResourceTiming entry (startTime)
domain_type The categorization of the resource's domain (e.g., a CDN, 1st party, or 3rd party) Derived from comparing the origin of the resource
res_type The more specific type of resource

Replay metrics

Field Description Source Reference
events The user and browser events (click, scroll, load, unload, error, etc.) DOM APIs -
DOM Snapshots The periodic snapshots of the DOM window and document -

Related article

Capturing RUM metrics

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