{"uid":"cap_MEfNVF0wJaK1R26LW9aQJ","slug":"page-speed-lab-measurement-0da59e6e","name":"Page Speed Lab Measurement","description":"Load one public URL once in headless Chromium and report what that load measured: navigation timings (TTFB, DOMContentLoaded, load), Web Vitals read from the page's own performance entries (LCP, FCP, CLS, total blocking time from long tasks), total transfer bytes, request count, the 5 heaviest resources, render-blocking scripts and styles, console errors, and an opportunities array computed from that same load: what to fix and where.","url":"https://agent402.tools/api/page-speed?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","description":"Public http(s) URL to load and measure"},"device":{"enum":["mobile","desktop"],"type":"string","description":"Viewport profile: mobile (412x823, touch) or desktop (1350x940). Default mobile"}}},"responseSchema":{"type":"json","example":{"note":"full example in /openapi.json","truncated":true}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_zza_Z1LpWVTcbc0oBhN6W","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Loads a public URL once in headless Chromium and returns navigation timings, Web Vitals, transfer stats, heaviest resources, render-blocking assets, and console errors for mobile or desktop viewports.","exampleAgentPrompt":"Can you load https://www.example.com in a mobile viewport and report the TTFB, LCP, total page weight, any render-blocking resources, and console errors?","exampleUseCases":[{"title":"Pre-launch performance audit","prompt":"Before we go live, can you load https://staging.myapp.com on desktop and tell me the load time, LCP, CLS, total transfer size, and any render-blocking scripts I should fix?"},{"title":"Diagnosing slow mobile landing page","prompt":"Our mobile conversion is bad — can you check https://www.mybrand.com/promo on a mobile viewport and tell me the TTFB, largest contentful paint element, and which resources are heaviest?"},{"title":"Monitoring competitor page speed","prompt":"Can you measure how fast https://www.competitor.com loads on desktop — I want TTFB, DOMContentLoaded, total bytes transferred, and any console errors it throws?"}],"resultDescription":"A JSON object containing: navigation timings (TTFB, DOMContentLoaded, load in ms), Web Vitals (LCP, FCP, CLS, total blocking time, long task count), transfer stats (total bytes, request count, failed requests), viewport dimensions, the 5 heaviest resources with type and bytes, render-blocking scripts/styles, console errors, whether the page reached network idle, and a measurement metadata block clarifying this is a single lab run (not field data or Lighthouse score).","failureModes":["URL is not publicly accessible or requires authentication — returns failed/error status","URL times out or page never reaches network idle","Invalid or non-HTTP(S) URL provided — schema validation error","Headless Chromium crashes or encounters an unrenderable page","Shared infrastructure load may cause variable results across repeated calls"],"whenToPreferThis":"Choose this endpoint when you need a quick, inexpensive single-run lab measurement of a public URL's load performance including Web Vitals and resource breakdown, without requiring a full Lighthouse audit pipeline. It is ideal for one-off checks, pre-launch audits, or scripted monitoring where you need raw timing data and resource diagnostics rather than a normalized Lighthouse score. Note that this is a single run from one server location with no network throttling, so it is not a substitute for field RUM data or multi-run averages.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T07:11:18.933Z","isFirstParty":false,"canonicalSlug":"page-speed-lab-measurement-0da59e6e"}