AI SEO Content Quality Analyzer for WordPress Using PHP and OpenAI

I've used Yoast and Rank Math for years. Both are solid, but they kept telling me what was wrong, keyword density too low, meta too long without ever telling me why the content wasn't ranking. So I built something different.

This tutorial walks through building a WordPress plugin that uses OpenAI to analyze your post content the way a search engine actually thinks about it, checking search intent alignment, content depth, and semantic quality then gives you a score and specific suggestions right inside the post editor.

Once installed, the plugin analyzes each post and:

  • Analyze the alignment of search intent
  • Verify the content's completeness
  • Identify generic or thin sections
  • Examine the quality of semantic SEO
  • Make suggestions for headings, FAQs, and enhancements
  • Give an AI SEO score between 0 and 100.

This is much more advanced than conventional SEO plugins.

Requirements

  • WordPress 6.x
  • PHP 8.1+
  • Composer (optional)
  • An OpenAI API key
  • Basic WordPress plugin development knowledge

Step 1: Create the WordPress Plugin

Create a new plugin folder:

    
        wp-content/plugins/ai-seo-analyzer/
    

Create ai-seo-analyzer.php

    
        /**
        * Plugin Name: AI SEO Content Quality Analyzer
        * Description: Analyzes WordPress content quality using AI and provides SEO recommendations.
        * Version: 1.0.0
        * Author: phpcmsframework.com
        */

        if (!defined('ABSPATH')) exit;
    

Activate the plugin from WP Admin → Plugins.

Step 2: Add Meta Box in Post Editor

    
        add_action('add_meta_boxes', function () {
            add_meta_box(
                'ai_seo_box',
                'AI SEO Content Analyzer',
                'ai_seo_meta_box',
                ['post', 'page'],
                'side',
                'high'
            );
        });

        function ai_seo_meta_box($post)
        {
            echo '<button class="button button-primary" id="ai-seo-analyze">Analyze Content</button>';
            echo '<div id="ai-seo-result" style="margin-top:10px;"></div>';
        }
    

Step 3: AJAX Handler (PHP Only)

    
        add_action('wp_ajax_ai_seo_analyze', 'ai_seo_analyze');

        function ai_seo_analyze()
        {
            $postId = intval($_POST['post_id']);
            $post = get_post($postId);

            if (!$post) {
                wp_send_json_error('Post not found');
            }

            $analysis = ai_seo_analyze_content($post->post_title, $post->post_content);

            wp_send_json_success($analysis);
        }
    

Step 4: AI Content Analysis Function

    
        function ai_seo_analyze_content($title, $content)
        {
            $prompt = "
        Analyze the SEO quality of the following content.

        Return JSON with:
        - seo_score (0-100)
        - intent_match (Good/Average/Poor)
        - strengths (list)
        - weaknesses (list)
        - improvement_suggestions (list)
        - suggested_headings
        - suggested_faqs

        Title:
        $title

        Content:
        " . strip_tags($content);

            $payload = [
                'model' => 'gpt-4o-mini',
                'messages' => [
                    ['role' => 'system', 'content' => 'You are an expert SEO auditor.'],
                    ['role' => 'user', 'content' => $prompt]
                ],
                'temperature' => 0.2
            ];

            $ch = curl_init('https://api.openai.com/v1/chat/completions');
            curl_setopt_array($ch, [
                CURLOPT_RETURNTRANSFER => true,
                CURLOPT_HTTPHEADER => [
                    'Content-Type: application/json',
                    'Authorization: Bearer ' . getenv('OPENAI_API_KEY')
                ],
                CURLOPT_POST => true,
                CURLOPT_POSTFIELDS => json_encode($payload)
            ]);

            $response = json_decode(curl_exec($ch), true);
            curl_close($ch);

            return json_decode($response['choices'][0]['message']['content'], true);
        }
    

Step 5: JavaScript for Admin UI

    
        add_action('admin_footer', function () {
        ?>
        <script>
        jQuery(function ($) {
            $('#ai-seo-analyze').on('click', function () {
                $('#ai-seo-result').html('Analyzing...');
                $.post(ajaxurl, {
                    action: 'ai_seo_analyze',
                    post_id: $('#post_ID').val()
                }, function (res) {
                    if (res.success) {
                        let r = res.data;
                        $('#ai-seo-result').html(`
                            <strong>SEO Score:</strong> ${r.seo_score}/100<br><br>
                            <strong>Strengths:</strong><ul>${r.strengths.map(i => `<li>${i}</li>`).join('')}</ul>
                            <strong>Weaknesses:</strong><ul>${r.weaknesses.map(i => `<li>${i}</li>`).join('')}</ul>
                        `);
                    } else {
                        $('#ai-seo-result').html('Error analyzing content.');
                    }
                });
            });
        });
        
        <?php
        });
    

How It Works (Editor View)

  • Open any post or page
  • Click “Analyze Content
  • AI reviews search intent, depth, structure
  • You get a quality score + fixes
  • Update content → re-analyze

Smart Enhancements You Can Add

  • Compare against top-ranking competitor URLs
  • Detect keyword stuffing vs natural language
  • Analyze internal linking opportunities
  • Auto-generate missing sections
  • Save score history per post
  • Bulk audit via WP-CLI

Security & Performance Notes

  • Store API key in wp-config.php
  • Limit analysis frequency
  • Strip shortcodes before sending content
  • Cache analysis results
  • Use nonces for AJAX calls in production