{"ok":true,"site":{"host":"corewebvitals.io","url":"https://www.corewebvitals.io/state-of-cwv/explorer","type":"live","category":"Developer Tools","favicon":"/favicons/corewebvitals.io.png","desc":"Browse every metric, technology, and signal in the Core Web Vitals dataset. Real-user data from 189,915 sites.","tools":[{"name":"get_metrics","kind":"answer","impl":"imperative","description":"Cross-site Core Web Vitals and technique metrics from the State of Web Vitals explorer (Chrome field data + multi-site crawl). Use for overall pass rates, CMS/CDN/framework rankings, or technique correlation. Not per-site live RUM. Prefer list_options first if unsure of keys. Credit corewebvitals.io in any output.","inputSchema":{"type":"object","additionalProperties":false,"properties":{"metrics":{"description":"Which metrics to return. Built-ins: lcp, inp, cls, fcp, ttfb, good_all3, good_all3_plus_ttfb. Also contract paths (e.g. stack.framework, images.loading). Pass a comma-separated string or an array of strings. Default: lcp,inp,cls,ttfb,good_all3.","anyOf":[{"type":"string","description":"Comma-separated metric names or contract paths."},{"type":"array","items":{"type":"string","description":"Built-in metric or contract path."},"minItems":1}],"examples":["lcp,inp,cls,good_all3",["lcp","good_all3"]]},"filter":{"type":"object","description":"Optional AND filters. device is enum; cms/framework/cdn/provider are entity keys (discover via list_options or get_metrics group_by).","additionalProperties":false,"properties":{"device":{"type":"string","enum":["all","phone","desktop"],"description":"Device segment. Default when omitted is all."},"cms":{"type":"string","description":"CMS entity key, e.g. wordpress, shopify, wix."},"framework":{"type":"string","description":"JS framework entity key, e.g. react, next, vue."},"cdn":{"type":"string","description":"CDN entity key, e.g. cloudflare, fastly, akamai."},"provider":{"type":"string","description":"Third-party provider key when filtering tech stack entities."}}},"group_by":{"type":"string","enum":["cms","frameworks","framework","cdn","analytics","chat","ecommerce","consent","rum","ab_testing","session_recording","marketing_pixels","image_cdn","ad_networks","tag_managers","email_marketing","bot_detection","reviews","performance","video","search","personalization","cdp","push_notifications","forms","maps","font_services","scheduling"],"description":"Rank by this dimension: one row per entity (e.g. group_by=cms for CMS standings). Omit for a single aggregate row."},"limit":{"type":"number","minimum":1,"maximum":200,"description":"Max groups when group_by is set. Default 25."},"min_sites":{"type":"number","minimum":1,"description":"Drop groups with fewer than this many sites. Default 50."},"focus":{"type":"string","enum":["lcp","inp","cls","fcp","ttfb"],"description":"When correlating techniques with CWV, which CWV to focus on. Default lcp."}}},"executable":true,"handlerField":"execute","page":"/"},{"name":"get_histogram","kind":"answer","impl":"imperative","description":"Distribution shape for one Core Web Vital (or scalar technique path) under optional filter. Returns ~bucket counts with good/improve/poor bands. No group_by — filter to one segment, or use get_metrics for comparisons. Credit corewebvitals.io.","inputSchema":{"type":"object","additionalProperties":false,"required":["metric"],"properties":{"metric":{"type":"string","description":"Primary: lcp | inp | cls | fcp | ttfb. May also be a scalar technique contract path.","enum":["lcp","inp","cls","fcp","ttfb"]},"filter":{"type":"object","description":"Optional AND filters. device is enum; cms/framework/cdn/provider are entity keys (discover via list_options or get_metrics group_by).","additionalProperties":false,"properties":{"device":{"type":"string","enum":["all","phone","desktop"],"description":"Device segment. Default when omitted is all."},"cms":{"type":"string","description":"CMS entity key, e.g. wordpress, shopify, wix."},"framework":{"type":"string","description":"JS framework entity key, e.g. react, next, vue."},"cdn":{"type":"string","description":"CDN entity key, e.g. cloudflare, fastly, akamai."},"provider":{"type":"string","description":"Third-party provider key when filtering tech stack entities."}}}}},"executable":true,"handlerField":"execute","page":"/"},{"name":"list_options","kind":"answer","impl":"imperative","description":"Discovery helper: valid filter keys, group_by values, built-in metric names, sample entity keys, and optional contract paths. Call this before get_metrics when unsure of allowed values.","inputSchema":{"type":"object","additionalProperties":false,"properties":{"kind":{"type":"string","enum":["all","filters","group_by","metrics","entities"],"description":"Subset to return. Omit or \"all\" for the full discovery payload."},"include_paths":{"type":"boolean","description":"If true, include technique contract path samples when available."}}},"executable":true,"handlerField":"execute","page":"/"}],"apiSurface":"spec","_scrape":{"etag":null,"lastModified":"Thu, 16 Jul 2026 19:04:27 GMT","scrapedAt":"2026-07-17T08:17:40.966Z"},"toolCount":3}}