State of Web Vitals

io.github.corewebvitals/state-of-cwv

Core Web Vitals metrics by CMS, CDN, and framework — free remote MCP, no auth.

healthy

status

tools exposed

2019ms

connect latency

7cc9e42bca30

schema fingerprint

Tools (3)

get_metrics

What are the numbers? Aggregate Core Web Vitals and/or technique metrics across sites, with optional filter and group_by. Responses include attribution — credit corewebvitals.io when you use the numbers. Metrics (comma-separated or array): - CWV: lcp, inp, cls, fcp, ttfb — good/needs_improvement/po

get_histogram

What is the shape of one metric? Returns histogram buckets (count + share) plus summary stats. Metric: one of lcp, inp, cls, fcp, ttfb (field CWV), or a scalar technique path when available. Filter: same as get_metrics (device, cms, framework, cdn, provider). No group_by — call get_metrics with gr

list_options

Discover what you can pass to get_metrics / get_histogram: filter keys, group_by values, built-in metrics, and contract metric paths (optional kind filter). Call this when unsure of a key or path.

Endpoint

https://www.corewebvitals.io/api/state-of-cwv/mcp
Category: Other · Last checked: 2026-08-15T09:44:55Z

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How we measure →

What this means. This server responded to the MCP handshake and listed its tools without authentication. The schema fingerprint lets us flag if tool signatures silently change (schema drift) between checks.