# Bulk Domain Authority Checker: PageRank & Referring Domains (`eligible_fame/domain-authority-checker`) Actor

Bulk domain authority checker built on open data: a 0-100 authority score, Common Crawl PageRank & harmonic-centrality rank, referring domains and Majestic Million rank for thousands of domains in seconds. No Moz/Ahrefs/Semrush login or API key.

- **URL**: https://apify.com/eligible_fame/domain-authority-checker.md
- **Developed by:** [Offladder](https://apify.com/eligible_fame) (community)
- **Categories:** SEO tools, Lead generation, Developer tools
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

Pay per event

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/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
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.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## 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.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## Bulk Domain Authority Checker — Open PageRank, Referring Domains & Authority Score

Check **domain authority in bulk** without a Moz, Ahrefs or Semrush subscription. Paste up to 100,000 domains or URLs and get back, for each domain:

- an **authority score from 0 to 100**, using a transparent and documented formula
- the **Common Crawl PageRank rank** and **harmonic-centrality rank** among 133 million domains
- the number of **referring domains**, meaning distinct linking domains in the Common Crawl web graph
- the **Majestic Million rank**, referring subnets and referring IPs (top 1M sites)
- a timestamp and the data release used

The checker is fast: 1,000 domains usually finish in a few seconds, because the index is pre-computed and the actor never crawls or scrapes anything.

### What is it for?

- **Link building and outreach:** qualify guest-post and backlink prospects, and drop low-authority or spammy sites before you pitch.
- **SEO audits and competitor research:** compare the domain strength of competitors, publishers and referring sites.
- **Expired domains and domain investing:** screen lists of domains for real link equity.
- **Lead scoring and enrichment:** add a website-authority column to CRM, Clay or Google Sheets lists.
- **Ad, affiliate and PR vetting:** check that a publisher is an established site.

### Input

```json
{
  "domains": ["apify.com", "https://www.nytimes.com/section/technology", "blog.example.co.uk"],
  "minAuthorityScore": 0,
  "includeNotIndexed": true
}
```

- **Input format:** URLs, subdomains and `www.` are reduced to the registrable domain. For example, `blog.example.co.uk` becomes `example.co.uk`.
- **Duplicates** are removed.
- **Invalid entries,** such as IP addresses or text that is not a domain, produce a free `invalid` row and do not stop the run.
- **Empty input** checks five example domains.

### Output example

```json
{
  "domain": "stripe.com",
  "status": "ok",
  "authority_score": 92,
  "harmonic_centrality_rank": 64,
  "pagerank_rank": 66,
  "referring_domains": 710778,
  "majestic_rank": 143,
  "majestic_ref_subnets": 51298,
  "hosts_crawled": 95,
  "data_release": "cc-main-2026-jul-aug-sep",
  "checked_at": "2026-10-18T09:00:00+00:00"
}
```

The `status` field takes one of these values:

| status | meaning | charged? |
|---|---|---|
| `ok` | The domain was found in the web graph and scored. | yes |
| `not_indexed` | No other domain links to it in this crawl. The score is 0. | **free** |
| `invalid` | The input is not a usable domain. | **free** |
| `error` | The index was temporarily unavailable. | **free** |

### How the authority score is calculated

The score is a weighted blend of three open link-graph signals from the Common Crawl domain-level web graph (133M domains, 2.1B domain-to-domain links):

```
raw_score       = 0.4 × harmonic_centrality_score + 0.3 × pagerank_score + 0.3 × referring_domains_score
rank score         = 100 × (1 − log10(rank) / log10(133,241,980))
referring score    = 100 × log10(1 + referring_domains) / log10(1 + max_referring_domains)
```

- **Harmonic centrality** measures how close a domain is to all other domains in the link graph. It is hard to game with link farms.
- **PageRank** is the classic link-equity measure.
- **Referring domains** is the number of distinct domains that link to this domain.

The raw score is then mapped onto a familiar 0–100 authority scale with a fixed, monotonic piecewise curve, so the ranking order never changes:

| raw | 20 | 35 | 45 | 51 | 60 | 70 | 79 | 85 | 100 |
|---|---|---|---|---|---|---|---|---|---|
| authority_score | 10 | 25 | 45 | 60 | 72 | 83 | 92 | 97 | 100 |

**Score scale:** the biggest global sites (Google, Facebook, Wikipedia) score about 90–100, established mid-size brands about 55–75, and small or new sites stay low (under about 30). Moving from 80 to 90 is much harder than moving from 20 to 30. The score is **not** Moz DA or Ahrefs DR and will not match them exactly, but it is built from the same kind of link data. Every input is published with it, so you can apply your own weighting.

### Data sources and licences

- **[Common Crawl web graph](https://commoncrawl.org/web-graphs)** (release `cc-main-2026-jul-aug-sep`), used under the [Common Crawl Terms of Use](https://commoncrawl.org/terms-of-use). It provides the harmonic-centrality rank, PageRank rank, referring domains and host counts.
- **[Majestic Million](https://majestic.com/reports/majestic-million)**, licensed CC BY 3.0 by Majestic-12 Ltd. It provides the Majestic rank, referring subnets and referring IPs.

The actor does not scrape Moz, Ahrefs, Semrush or any search engine. The data is refreshed when Common Crawl publishes a new quarterly web graph.

### Pricing

Pricing is pay per event:

- **$0.02 per run start**
- **$1.50 per 1,000 scored domains** ($0.0015 per `domain-result`)

Invalid, not-indexed and failed domains are free. Use `minAuthorityScore` to pay only for domains above your threshold. You can also set a maximum charge per run in Apify.

### Use with AI agents (MCP)

You can call this actor as a tool from Claude, Cursor, ChatGPT and other agents through the [Apify MCP server](https://mcp.apify.com):

```
https://mcp.apify.com?tools=eligible_fame/domain-authority-checker
```

Example prompts:

- "Check the domain authority of these 200 prospects and keep only those above 40."
- "Compare the referring domains of my site and my top 5 competitors."

The output is flat JSON with stable field names, so agents can easily filter and rank it. You can also call it from the Apify API, the Python or JavaScript clients, Make, Zapier or n8n.

### FAQ

**Is this Moz Domain Authority?**
No. It is an open-data alternative with a documented formula. Moz DA is proprietary.

**Why does my domain show `not_indexed`?**
No other registrable domain linked to it in the crawl. This is common for very new or private sites. You are not charged for it.

**Are subdomains scored separately?**
No. The score is given for the registrable domain, such as `example.co.uk`.

**How fresh is the data?**
It uses the latest quarterly Common Crawl web graph. The release used is included in every row.

# Actor input Schema

## `domains` (type: `array`):

Domains, hostnames or full URLs (one per line). Subdomains and paths are reduced to the registrable domain, e.g. https://blog.example.co.uk/post → example.co.uk. Duplicates are removed. Up to 100,000 per run. Leave empty to check a few example domains.

## `minAuthorityScore` (type: `integer`):

Only output (and only charge for) domains with an authority score at or above this value. 0 = output all.

## `includeNotIndexed` (type: `boolean`):

Also output a free row (status not_indexed, score 0) for domains that have no links from other domains in the Common Crawl web graph.

## Actor input object example

```json
{
  "domains": [
    "apify.com",
    "wikipedia.org",
    "github.com",
    "bbc.co.uk",
    "example.com"
  ],
  "minAuthorityScore": 0,
  "includeNotIndexed": true
}
```

# Actor output Schema

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

No description

# 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 = {
    "domains": [
        "apify.com",
        "wikipedia.org",
        "github.com",
        "bbc.co.uk",
        "example.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("eligible_fame/domain-authority-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 = { "domains": [
        "apify.com",
        "wikipedia.org",
        "github.com",
        "bbc.co.uk",
        "example.com",
    ] }

# Run the Actor and wait for it to finish
run = client.actor("eligible_fame/domain-authority-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 '{
  "domains": [
    "apify.com",
    "wikipedia.org",
    "github.com",
    "bbc.co.uk",
    "example.com"
  ]
}' |
apify call eligible_fame/domain-authority-checker --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,eligible_fame/domain-authority-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/0LOCUvXq30j9XUzRZ/builds/5xCtmlWMm11hB8NKU/openapi.json