# Core Web Vitals Checker - Bulk PageSpeed & CrUX Reports (`eliai/core-web-vitals-checker`) Actor

Bulk Core Web Vitals audits via the official PageSpeed Insights API: score, LCP, CLS, TBT + real-user CrUX assessment per URL. $0.01/report, no start fee. Failed URLs are free.

- **URL**: https://apify.com/eliai/core-web-vitals-checker.md
- **Developed by:** [Anthony Snider](https://apify.com/eliai) (community)
- **Categories:** SEO tools, Developer tools, Automation
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

$10.00 / 1,000 vitals reports

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/platform/actors/running/actors-in-store#pay-per-event

## What's an Apify Actor?

Actors are web data automations that power AI and operations. They run on the Apify platform to scrape websites, process data, connect APIs, and automate workflows.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
- **Agentic workflows and local Actor development** — [Agent Skills](https://apify.com/.well-known/agent-skills/index.json) with the [Apify CLI](https://docs.apify.com/cli/docs.md): `npm install -g apify-cli`, then `apify login`.
- **JavaScript/TypeScript projects** — the official [JS/TS client](https://docs.apify.com/api/client/js/docs.md): `npm install apify-client`.
- **Python projects** — the official [Python client](https://docs.apify.com/api/client/python/docs.md): `pip install apify-client`.
- **Any other language** — the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).

# README

## Core Web Vitals Checker — Bulk PageSpeed & CrUX Reports

Audit **Core Web Vitals for up to 100 URLs in one run**. Each URL gets a client-ready report with the Lighthouse **performance score (0–100)**, lab metrics (**LCP, CLS, TBT, FCP, Speed Index**), **real-user CrUX field data** (LCP, INP, CLS percentiles) with **Google's own pass/fail Core Web Vitals assessment**, and the **top 5 speed opportunities** ranked by estimated savings.

Data comes straight from the **official Google PageSpeed Insights API v5** — the same engine behind pagespeed.web.dev — on our own provisioned API quota, so runs don't fail on the shared anonymous limit.

### Why this one

- **$0.01 per report, flat.** No actor-start fee, no per-metric micro-charges. Comparable actors charge a $0.10 start fee plus $0.02–$0.08 per URL before extras.
- **Failed URLs are free.** You pay only for delivered reports — an unreachable page is recorded with its error and never billed.
- **Field + lab in one row.** Lab scores tell you what Lighthouse simulated; CrUX field data tells you what real Chrome users experienced, including the assessment Google actually ranks with.

### Input

```json
{
  "urls": ["https://example.com", "https://example.com/pricing"],
  "strategy": "mobile",
  "maxUrls": 25
}
```

`strategy` is `mobile` (Google's ranking basis, default) or `desktop`.

### Output (one dataset item per URL)

```json
{
  "ok": true,
  "url": "https://example.com",
  "performanceScore": 84,
  "lab": { "lcpMs": 2100, "cls": 0.01, "tbtMs": 150, "fcpMs": 900, "speedIndexMs": 1800 },
  "field": {
    "available": true,
    "coreWebVitalsAssessment": "FAST",
    "lcpMs": 1900, "inpMs": 140, "cls": 0.02
  },
  "topOpportunities": [
    { "id": "render-blocking-resources", "title": "Eliminate render-blocking resources", "estimatedSavingsMs": 780 }
  ],
  "source": "Google PageSpeed Insights API v5"
}
```

`field.available` is `false` for low-traffic pages Google has no real-user data for — the lab metrics still come through.

### Common uses

- **Agency reporting**: monthly vitals rows for every client page, exportable as JSON/CSV/Excel from the dataset.
- **Site migration QA**: audit the top-100 URLs before and after a redesign and diff the scores.
- **Monitoring**: schedule a weekly run and alert when a page's assessment leaves "FAST".

### Works well with

- [SEO Audit Tool](https://apify.com/eliai/website-seo-tech-auditor) — title, meta, schema, robots and sitemap checks for the same URLs.
- [Page Weight Analyzer](https://apify.com/eliai/webpage-page-weight-analyzer) — byte-level breakdown of what makes a page heavy.
- [Redirect Chain Checker](https://apify.com/eliai/redirect-chain-checker) — where every URL actually lands before you audit it.
- [Complete Site Audit](https://apify.com/eliai/complete-site-audit) — the whole-site grade in one run.

### FAQ

**Is this the same data as pagespeed.web.dev?** Yes — the official PageSpeed Insights API v5, called with your chosen device strategy.

**What's the difference between lab and field data?** Lab (Lighthouse) is a controlled simulation run at audit time; field (CrUX) is aggregated from real Chrome users over the past 28 days. Google's ranking systems use field data — that's the `coreWebVitalsAssessment` value.

**How long does a run take?** PageSpeed audits take 30–60 seconds per URL on Google's side; this actor runs three in parallel, so 25 URLs finish in roughly 7 minutes.

**Why did a URL come back `ok: false`?** The page was unreachable or PageSpeed couldn't analyze it — the error is in the record and the URL was not charged.

# Actor input Schema

## `urls` (type: `array`):

Webpage URLs to audit. Each URL gets one vitals report: performance score, LCP, CLS, TBT lab metrics, plus real-user CrUX field data when Google has it.

## `strategy` (type: `string`):

Audit as mobile (what Google ranks by) or desktop.

## `maxUrls` (type: `integer`):

Maximum number of URLs to audit in one run.

## Actor input object example

```json
{
  "urls": [
    "https://apify.com",
    "https://example.com"
  ],
  "strategy": "mobile",
  "maxUrls": 25
}
```

# Actor output Schema

## `results` (type: `string`):

Every item this run produced, as JSON.

## `resultsCsv` (type: `string`):

The same items as a spreadsheet-ready CSV.

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "urls": [
        "https://apify.com",
        "https://example.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("eliai/core-web-vitals-checker").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "urls": [
        "https://apify.com",
        "https://example.com",
    ] }

# Run the Actor and wait for it to finish
run = client.actor("eliai/core-web-vitals-checker").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "urls": [
    "https://apify.com",
    "https://example.com"
  ]
}' |
apify call eliai/core-web-vitals-checker --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,eliai/core-web-vitals-checker"
        }
    }
}

```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/UGmey7N2396MAQ4YM/builds/kvnhoWjETRjxhsL8M/openapi.json