DiagnoSEO – Fast and Automated On-page SEO vs SEO Writing Assistant SEMrush Custom Fields

DiagnoSEO is a performance-first SEO plugin for WordPress users who want full control without bloat. DiagnoSEO is the lowest memory WordPress SEO plugin, confirmed by independent performance tests on WP Hive and Plugin Tests. Built for speed, scalability, and real SEO work, DiagnoSEO stays fast even on large and complex websites. It uses minimal memory, optimized code (less than 100KB of a ZIP file), and a clean architecture designed with Core Web Vitals in mind. This is not a plugin that adds features at the cost of performance. DiagnoSEO is built for websites where speed, control, and SEO quality actually matter. You get predictable performance backed by 17+ years of real-world SEO experience, and a plugin especially valued by experienced SEO specialists who need advanced SEO control, predictable behavior, and a clean interface. DiagnoSEO is also part of the DiagnoSEO SEO Software Suite, an AI-powered SEO platform with over 50 tools for audits, keyword research, competitor analysis, backlinks, and AI-assisted content workflows. The WordPress plugin works as a natural extension of this ecosystem. Who is DiagnoSEO for? 👤 DiagnoSEO is designed for users who want ease of use, control, and performance: Beginners who want clear and practical SEO guidance Bloggers and content creators Small and medium-sized businesses WooCommerce store owners Developers and agencies SEO professionals who care about performance and advanced SEO control The interface is clean and focused. Advanced options are available when needed, without overwhelming the user. Why choose DiagnoSEO? ⭐ Most SEO plugins try to do everything. DiagnoSEO focuses on what actually moves the needle. Instead of bloated dashboards and unnecessary features, DiagnoSEO helps you improve content quality, maintain full control over SEO signals, keep your website fast, and scale SEO safely as your site grows. It is a modern, performance-focused SEO plugin for websites that need more than basic SEO tweaks. DiagnoSEO was named a finalist at the European Search Awards 2025 in two major categories: Best SEO Software Suite and Best Software Innovation. This industry recognition underscores its innovation and effectiveness. Core SEO Features (Free) Custom meta titles and meta descriptions Meta tag templates Google search snippet preview Meta robots control Custom canonical URLs Advanced Schema.org support Breadcrumbs with HTML and Schema Open Graph metadata and social previews XML sitemap Optimization for multiple related keywords SEO checkpoints and actionable on-page recommendations Content analyzer with keyword placement checks Live SEO score while editing Redirect attachment pages to image files Easy insertion of analytics and tracking codes Fully compatible with Multi Premium WordPress Theme All features are built with performance and usability in mind. WordPress SEO Audit & Checker 🔍 See your SEO score instantly Find error-level issues hurting your visibility Discover quick SEO wins you can fix fast Get clear priorities on what to fix first Check posts, pages, products, and key SEO settings automatically in seconds DiagnoSEO also includes a built-in WordPress SEO Audit & Checker that helps you quickly review important on-page and site-wide SEO issues directly inside WP admin. It analyzes metadata, content, structure, links, images, accessibility, schema, WooCommerce products, and product categories using WordPress and DiagnoSEO plugin data only, so you get fast, actionable SEO insights in a lightweight workflow. Unique Pro SEO Features 🚀 DiagnoSEO Pro includes advanced SEO features rarely found in other SEO plugins. For a detailed feature comparison with other popular SEO plugins, see: Yoast vs Rank Math vs DiagnoSEO. Advanced Schema, E-E-A-T & SERP Enhancements ReviewedBy schema support for stronger E-E-A-T signals Post rating with stars and schema for higher click-through rates in SERPs SameAs schema support for better social media and brand entity connections LocalBusiness schema support Multiple Schema.org types per page Advanced Internal Linking & Content Structure Anchor text control in post lists without changing H1 for better SEO and UX Affiliate deeplink hider – a safer alternative to rel=”nofollow” that protects internal link equity and prevents link juice leaks Automatic table of contents for improved UX and internal linking SEO Categories widget for better internal linking of nested categories Advanced SEO Control & Privacy Advanced content quality checkpoints for better SEO audits XML sitemap with customizable filename for better privacy Meta referrer support for privacy and analytics control Performance-focused advanced options for better SEO, UX, and conversions These features are designed to solve real SEO problems, not to inflate feature lists. More Pro SEO Features 🔥 AI, Automation & Content Intelligence AI-powered meta title and meta description generator AI-powered comments generator Unlocked useful content quality and SEO checkpoints Related keyword suggestions based on semantics Internal linking suggestions Advanced SEO Management & Indexing Redirection manager with 301 and 302 redirects IndexNow support for super-fast indexing in Bing and Yandex Option to change all external links to nofollow (Multisite supported) Google News XML sitemap HTML sitemap block Content, UX & Visibility Enhancements Automatic table of contents and Table of Contents block Related & Featured posts widget Featured posts widget WooCommerce & Advanced Website SEO Advanced WooCommerce SEO metadata SEO Categories widget for WooCommerce DiagnoSEO SEO Software Suite Access DiagnoSEO Pro extends WordPress SEO with access to professional SEO tools and workflows beyond the WordPress dashboard. Access to professional SEO tools from the DiagnoSEO All-in-One SEO Software Suite Support for SEO audits, keyword research, competitor analysis, backlinks, and content workflows Website crawl tool access (e.g. 404 detects and 20 more factors) Access to super detailed and advanced SEO Checker tool (200+ factors) Access to competitors analysis SEO tool (using AI and real search data) Designed for SEO specialists, agencies, and teams managing SEO beyond WordPress Support & Professional Use Dedicated premium SEO support Read full features list and details AI-Powered SEO (Pro) 🤖🔥 AI-Assisted Metadata & Content Support DiagnoSEO Pro uses the OpenAI API to generate or improve: Meta titles Meta descriptions Contextual comments for posts Metadata are generated based on SEO best practices. AI tools are designed to save time, support consistent SEO workflows, and help maintain content quality at scale. Easy Migration 🔄 Switching to DiagnoSEO is simple and safe. You can import SEO data from other popular SEO plugins (Yoast SEO, Rank Math, SEOPress, and many more) with no data loss and no SEO risk. Why switch to DiagnoSEO? 🚀 If your current SEO setup feels slow, bloated, overly complex, or limiting in advanced SEO control, DiagnoSEO gives you back speed, clarity, and full control without compromising performance. Optimize smarter. Stay fast. Stay in control. Switch to DiagnoSEO and experience performance-first SEO for WordPress.

The SEMrush SEO Writing Assistant plugin read only from post title and post content elements for the real time check. This lightweight plugin allows you to use an arbitrary value for that check in addition to those values. So, if you are using some kind of a page builders, field managers and so on, you have only to define a constant in your wp_config.php file and eventually to write a little bit of JavaScript code in order to specify which fields. Note that the plugin don’t replace SEMrush SEO Writing Assistant but is intended to be used together. Usage Once the plugin is activated you can configure it by defining following constants in your wp-config.php: SWA_SEMRUSH_CUSTOM_FIELDS_PLUGIN_AUTOENABLE Automatically enable use of additional text value for SEMrush check. The default value is false. This is the only configuration you have to do in order to have the plugin feature working. For example: define( 'SWA_SEMRUSH_CUSTOM_FIELDS_PLUGIN_AUTOENABLE', true ); SWA_SEMRUSH_CUSTOM_FIELDS_PLUGIN_INTERVAL Allows to change the interval between automatic updates of the text used by SEMrush checks. The default value is 5 seconds.For example: define( 'SWA_SEMRUSH_CUSTOM_FIELDS_PLUGIN_INTERVAL', 10 ); You can alernatavely control the plugins programmatically, by using semrush_seo_writing_assistant_post_types (optional) filter and SeoWritingAssistantSEMrushCustomFields JavaScript object (see below). API WordPress Hooks **swa_semrush_custom_fields_settings ** Filters plugin settings values. apply_filters( 'swa_semrush_custom_fields_settings', array $settings ) semrush_seo_writing_assistant_post_types Filters post types where to enable plugin. Default to array( 'post', 'page', 'product' ). apply_filters( 'semrush_seo_writing_assistant_post_types', array $post_types ) The filter has the same name as the one used by SEMrush SEO Writing Assistant plugin (since version 1.0.4) used for the same purpose. JavaScript Event seo-writing-assistant-semrush This event allows you to update the text for SEMrush analysis. The following example will update text for SEMrush check every 5 seconds, using excerpt and my_custom_fields custom field values (working both with block and classic editors): jQuery( document ).ready( function() { var swa = new SeoWritingAssistantSEMrushCustomFields( { interval: 5 } ); jQuery( document ).on( 'seo-writing-assistant-semrush', function( event, data ) { data.html += jQuery( '#excerpt' ).val() + "\n" + jQuery( '.editor-post-excerpt__textarea textarea').val() + "\n" + jQuery( '#my_custom_fields' ).val(); } ) } ); Note that if you have previously defined constant SWA_SEMRUSH_CUSTOM_FIELDS_PLUGIN_AUTOENABLE to true, you don’t have to create new SeoWritingAssistantSEMrushCustomFields object. JavaScript API setHtml() The following example will update programmatically the text used by SEMrush check with an arbitrary value: jQuery( document ).ready( function() { var swa = new SeoWritingAssistantSEMrushCustomFields( { interval: 0 } ); swa.setHtml( 'foo baz bar' ); } ); Advanced Custom Fields The plugin checks if Advanced Custom Fields is active in your WordPress instance and adds a custom setting to each field (only for input within text, radio and checkbox type, textarea and select elements) allowing you to add his value to SEMrush check without having to write any additional JavaScript code. Autodiscovery The plugin also automatically add to text used by SEMrush checks, the values of all HTML elements with swa-scf class or data-swa-scf attribute. This will applied only for input (within text, radio and checkbox type), textarea, and select elements.