Pull real-user Core Web Vitals field data for a set of origins/URLs from the CrUX API and CrUX History API within Google's quota
domain: developer.chrome.com · 6 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Enable the Chrome UX Report API in a Google Cloud project and generate an API key
Call the records.queryRecord endpoint with either a url or origin key (plus optional formFactor) to get the current 28-day rolling-average metrics
For trend analysis, call the CrUX History API's queryHistoryRecord endpoint, setting collectionPeriodCount up to 40 weekly data points (default 25)
Throttle requests to stay within the shared 150 queries/minute per Google Cloud project limit across both the record and history endpoints
Fall back to origin-level queries when a specific URL has insufficient traffic to appear in CrUX (page-level data requires a popularity threshold)
Schedule pulls to align with CrUX's weekly update cadence (History API refreshes Monday ~04:00 UTC with data through the prior Saturday) instead of polling daily
Known gotchas
150 QPM is a hard free-tier ceiling with no paid tier to raise it, so large URL sets need client-side rate limiting and queuing, not brute force
A URL/origin can be entirely absent from CrUX if it doesn't meet Chrome's minimum real-user traffic threshold — that's a coverage gap, not an error
Field data (CrUX) and lab data (Lighthouse/PSI) frequently disagree; don't treat PSI's lab score as a proxy for what CrUX field data will show
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