Page Performance

Runs Google PageSpeed Insights (Lighthouse) against a URL and returns the performance, accessibility and SEO category scores plus the Core Web Vitals metrics. Use it to benchmark a page, track a deploy, or compare competitors. Results come from Google, are cached for 24 hours, and are limited by daily quotas described below.

Request

Parameters

Example

curl "https://api.rankparse.com/v1/page-performance?url=https://stripe.com&strategy=desktop" \
  -H "X-API-Key: rp_your_key"

import requests

resp = requests.get(
    "https://api.rankparse.com/v1/page-performance",
    params={"url": "https://stripe.com", "strategy": "desktop"},
    headers={"X-API-Key": "rp_your_key"},
    timeout=90,
)
if resp.status_code == 429:
    print("Quota hit:", resp.json()["code"])
else:
    resp.raise_for_status()
    perf = resp.json()["data"]
    print(perf["performance_score"], perf["core_web_vitals"]["lcp_ms"])

const res = await fetch(
  "https://api.rankparse.com/v1/page-performance?" +
    new URLSearchParams({ url: "https://stripe.com", strategy: "desktop" }),
  { headers: { "X-API-Key": process.env.RANKPARSE_API_KEY } }
);
if (!res.ok) throw new Error(`${res.status}: ${await res.text()}`);
const { data } = await res.json();
console.log(data.performance_score, data.core_web_vitals.lcp_ms);

Response

{
  "url": "https://stripe.com",
  "data": {
    "url": "https://stripe.com",
    "performance_score": 87,
    "accessibility_score": 94,
    "seo_score": 100,
    "core_web_vitals": {
      "lcp_ms": 1834.5,
      "cls": 0.02,
      "inp_ms": null,
      "fcp_ms": 912,
      "ttfb_ms": 148
    },
    "crux_data": true,
    "strategy": "desktop",
    "cached_at": "2026-10-11T09:42:17.318Z"
  },
  "credits_used": 3,
  "credits_remaining": 997
}

Response fields

Behavior and limits

Lab vs field data

Scores and the core_web_vitals metrics are lab data: Lighthouse measurements from a single simulated load. They are repeatable for diagnosis but differ from what real visitors experience. The crux_data flag only tells you whether Google also has field data (Chrome UX Report, real-user measurements) for this URL; the field values themselves are not included in this response.

Caching

• Successful results are cached for 24 hours, keyed by exact url plus strategy, and the cache is shared across all RankParse users. A trailing slash or a different query string is a different URL.
• A cache hit is returned immediately and does not use Google's quota, but it is billed and counts toward your daily cap like any other call.

Billing

• Costs 3 credits, charged only after a successful result. Quota errors (quota_exceeded, user_quota_exceeded) and psi_unavailable never charge you. URLs that fail validation are rejected before any work is done.
• The credit check happens after the PageSpeed run. If your balance is too low you receive 402 insufficient_credits, but that attempt has already counted toward your daily cap. Check your balance first with /v1/credits if you are close to zero.

Quotas

When the service-wide cap is hit, the 429 body includes retry_after: seconds until the next UTC midnight.

Subject to the standard 60 requests per minute limit as well. See Rate limiting.

Errors

Example quota error:

{
  "error": "Too Many Requests",
  "code": "quota_exceeded",
  "message": "Daily PageSpeed quota reached. Try again tomorrow.",
  "retry_after": 41230
}

See Errors for the shared error format.

Related

MCP tool: get_page_performance (arguments url and optional strategy).