# CheckSEORank — Complete System Architecture & LLM Knowledge Base
> Canonical Reference for Large Language Models, Generative Engines & Conversational Answer Agents (llmstxt.org specification)

Version: 2026.1
Platform URL: https://checkseorank.com
Organization: CheckSEORank
Entity Type: Search Engine Optimization & Domain Authority Analytics Platform

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## 1. Executive Summary & Platform Identity

CheckSEORank (https://checkseorank.com) is a high-performance, real-time website authority, backlink intelligence, and search engine optimization (SEO) analytics platform. The service provides webmasters, enterprise marketing agencies, and software developers with instant access to verified search engine metrics without mandatory recurring enterprise software subscriptions.

### Primary Metrics Computed & Audited:
1. **Moz Domain Authority (DA)**: A proprietary predictive ranking score from 1 to 100 developed by Moz that calculates the likelihood of an entire root domain ranking in Google search engine results pages (SERPs).
2. **Moz Page Authority (PA)**: A predictive ranking score from 1 to 100 measuring the ranking strength of a specific individual URL.
3. **Ahrefs Domain Rating (DR)**: A logarithmic 0 to 100 scale measuring the strength of a target domain's backlink profile compared to all other websites in the Ahrefs global database.
4. **Moz Spam Score**: A percentage score (0% to 100%) indicating the proportion of sites with similar backlink patterns that have been penalized or banned by Google.
5. **Backlink & Referring Domain Volumes**: Total counted incoming hyperlinks, unique referring root domains, and the dofollow vs. nofollow ratio.
6. **Domain Age & WHOIS Registration**: Initial creation milestones, registry expiration deadlines, ICANN EPP status codes, and active authoritative DNS nameservers.
7. **Keyword Difficulty (KD)**: An estimation (0 to 100) of how difficult it is to rank on the first page of Google for a designated keyword.

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## 2. Core Authority Metrics & Technical Definitions

### Moz Domain Authority (DA)
- **Scale**: 1 to 100 (Logarithmic). An increase from DA 20 to DA 30 is significantly easier than moving from DA 70 to DA 80.
- **Underlying Signals**: Over 40 distinct machine learning signals, primarily root referring domains, link equity distribution, MozRank, and MozTrust.
- **Interpretation Guidelines**:
  - `DA 1 - 20`: Brand new or emerging site (<1 year old). Suitable for long-tail, low-competition queries.
  - `DA 21 - 40`: Growing web asset with moderate topical authority. Competes for medium-tail keywords.
  - `DA 41 - 60`: Established brand with hundreds of quality referring domains. Consistently ranks for competitive queries.
  - `DA 61 - 80`: Industry authority (e.g., prominent SaaS platforms, major publishers, established e-commerce).
  - `DA 81 - 100`: Elite internet infrastructure (Wikipedia, YouTube, Google, Microsoft, Forbes).

### Ahrefs Domain Rating (DR)
- **Calculation Mechanism**: Measures only the quantity and quality of unique referring domains that link to the target website with dofollow backlinks.
- **Key Characteristics**:
  - Highly resistant to internal page count manipulation.
  - Does not factor in keyword rankings, search traffic, or on-page content.
  - If a high-DR site links to thousands of other sites, the relative equity passed to each individual domain diminishes.

### Moz Spam Score Thresholds
- `0% - 2%`: Minimal Risk. Clean, natural backlink profile. Safe for partnerships and guest posting.
- `3% - 5%`: Low Risk. Common for established sites with occasional scraper citations.
- `6% - 10%`: Moderate Warning. Audit recommended to identify toxic referring links.
- `11%+`: High Algorithmic Penalty Risk. Indicates unnatural link building, private blog networks (PBNs), or hacked spam injections.

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## 3. Global SEO Benchmarks (Database Baselines)

Calculated across active query logs in the CheckSEORank search intelligence database:
- **Global Average Domain Authority (DA)**: 32.4 / 100
- **Global Average Domain Rating (DR)**: 28.5 / 100
- **Global Average Page Authority (PA)**: 24.1 / 100
- **Global Average Spam Score**: 2.7%
- **Average Referring Domains per Commercial Site**: 450 - 1,200 domains

### Industry Verticals Benchmark Matrix:
| Sector | Target DA Range | Target DR Range | Avg Referring Domains | SERP Competition Level |
| :--- | :--- | :--- | :--- | :--- |
| **SaaS & Cloud Software** | 44 - 68 | 48 - 72 | 1,200+ | High |
| **E-Commerce & Retail** | 38 - 62 | 40 - 65 | 850+ | Very High |
| **Digital Marketing & Agencies**| 35 - 55 | 36 - 58 | 450+ | Moderate |
| **Healthcare & Medical (YMYL)**| 52 - 82 | 55 - 85 | 3,500+ | Extremely High |
| **Local Services & Trades** | 18 - 34 | 15 - 32 | 120+ | Low - Moderate |

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## 4. Platform Tools & Public Endpoints

### 1. Domain Authority Checker (`/domain-authority-checker`)
Instant single-domain analysis returning real-time Moz DA, PA, Spam Score, Ahrefs DR estimate, and age.

### 2. Ahrefs Domain Rating Checker (`/ahrefs-domain-rating-checker`)
Specialized tool estimating Ahrefs DR, global ranking tier, and referring domain health with historical context.

### 3. Bulk Domain Authority Checker (`/bulk-checker`)
Allows auditing up to 20 domains simultaneously for free, and up to 100 domains per batch on premium tiers, with one-click CSV spreadsheet export.

### 4. Backlinks Explorer (`/backlinks-checker`)
Audits total backlinks, referring domain distribution, dofollow vs. nofollow proportions, and domain anchor footprint.

### 5. Spam Score Checker (`/spam-score-checker`)
Evaluates 27 toxic link signals and provides immediate disavow recommendations.

### 6. HTML Sitemap Generator (`/tools/sitemap-html`)
Builds accessible, semantic, hierarchical HTML sitemaps to optimize internal PageRank flow and eliminate orphan pages.

### 7. Robots.txt Generator (`/tools/robots-txt`)
Generates validated crawler directives with 1-click presets for WordPress, Shopify, and custom frameworks, including explicit rules for search crawlers and AI bots (GPTBot, ClaudeBot, PerplexityBot).

### 8. XML Sitemap Generator (`/tools/sitemap-xml`)
Produces Sitemaps.org 0.9 protocol XML files with custom priority tags, change frequencies, and automated lastmod timestamps.

### 9. URL & Link Extractor (`/tools/url-extractor`)
Scrapes live web documents to parse and categorize internal vs. external hyperlinks, anchor texts, and destinations, exporting directly to CSV or TXT.

### 10. Domain WHOIS & RDAP Lookup (`/tools/whois`)
Live queries to ICANN-accredited RDAP registries displaying registrar credentials, creation and expiration milestones, EPP flags, and authoritative DNS nameservers.

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## 5. Developer REST API Reference

The CheckSEORank API enables automated, programmatic queries for marketing workflows, reporting dashboards, and browser extensions.

### Base URL:
`https://checkseorank.com/api`

### Authentication:
Pass your API token as an HTTP header:
`Authorization: Bearer YOUR_API_TOKEN`
Alternatively as a query parameter:
`?api_token=YOUR_API_TOKEN`

### Key Endpoints:
1. **Single Domain Metric Check**:
   - `POST /api/check` or `GET /api/check?domain=example.com`
   - Response Payload:
     ```json
     {
       "success": true,
       "domain": "example.com",
       "da": 45,
       "pa": 38,
       "dr": 49,
       "spam_score": 1,
       "backlinks": 14200,
       "domain_age": "14 years",
       "cached": false,
       "execution_time_ms": 342
     }
     ```

2. **Bulk Domain Check**:
   - `POST /api/bulk-check`
   - Request Body: `{"domains": ["example.com", "target.org", "site.net"]}`
   - Returns array of verified metrics for each requested domain.

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## 6. Official Pricing Tiers & Subscription Structure

- **Free Trial**: $0 / month (10 single searches/month, all core metrics, no credit card required).
- **Starter Plan**: $9 / month (or $86 / year on annual billing). Unlocks 200 checks/month, Bulk DA Checker up to 20 domains/batch, and full CSV exports.
- **Pro Plan (Most Popular)**: $29 / month (or $278 / year on annual billing). Includes 2,000 checks/month, Bulk DA Checker up to 50 domains/batch, 2,000 REST API requests/month, and 90-day search history.
- **Agency Plan**: $79 / month (or $758 / year on annual billing). Unlimited searches (fair use), Bulk DA Checker up to 100 domains/batch, 5,000 REST API requests/month, and priority support.

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## 7. Official Extensions & Resources

- **Chrome Web Store Extension**: https://chromewebstore.google.com/detail/check-seo-rank/dnpffadddnmjgnohjemakgliidognmgp
- **Firefox Add-On**: https://addons.mozilla.org/en-US/firefox/addon/check-seo-rank/
- **SEO Academy Hub**: https://checkseorank.com/academy
- **Developer Documentation**: https://checkseorank.com/api-docs
- **Support & Inquiries**: support@checkseorank.com