# Schema markup (structured data) (/docs/on-page-and-technical-seo/schema-markup) --- type: Document title: Schema markup (structured data) description: What schema markup is, why it earns rich results, and how to add JSON-LD schema to WordPress with the ACF plugin. status: stable order: 22 generated: { by: human:ahmedraza, at: 2026-09-15T11:37:20Z } ksor: audience: [public] owner: human:ahmedraza approval: { by: human:ahmedraza, at: 2026-09-15T11:37:20Z } sources: - id: iskills-course-notes title: iSkills — course notes resource: "iSkills SEO course notes, compiled 2025" trust_tier: unverified build_id: sha256:25bcd9248ab7b7333e626a24b636e9eef514e339025ed762d0fe7ddd9b6486b8 source_commit: c890fca6aaa00f103ea9325ee0db7161c40e38ae ksor_version: 0.0.60 --- ## What is schema markup? Schema markup (structured data) is code added to a page that helps Google understand its content more precisely. When Google reads it, it can display rich results — star ratings, FAQs, event info — directly in search results, improving visibility and click-through rate (CTR).[^iskills-course-notes] ## Why add structured data - Helps Google understand content more clearly. - Improves how pages appear in results (featured snippets, knowledge panels). - Increases the chance of rich snippets. - Strengthens SEO and site credibility. ## How it works With a format like JSON-LD, Google extracts and displays enhanced information instead of reading only plain text. Example: an "Article" schema can surface the author name, published date, headline, thumbnail image, and ratings directly in the result. **Supported format:** JSON-LD (JavaScript Object Notation for Linked Data) — Google's recommended format, and the one to always use. ## Adding schema in WordPress with ACF 1. **Install ACF (Advanced Custom Fields)** — Plugins → Add New → search "ACF — Advanced Custom Fields" → Install → Activate. 2. **Create a custom field for schema** — Custom Fields → Add New, name it "Schema Markup", add a field of type Text Area named `schema`, set location rules to Post Type = Post and Post Type = Page, and publish the field group. 3. **Generate the schema code** — ask an AI tool for JSON-LD (Article, FAQ, Product, etc.) and copy the result. 4. **Paste it into `functions.php`** — Appearance → Theme File Editor → `functions.php`, and add: ```php function add_custom_schema_to_head() { if (is_single() || is_page()) { $schema = get_field('schema'); if (!empty($schema)) { echo ''; } } } add_action('wp_head', 'add_custom_schema_to_head'); ``` This pulls the schema from the ACF field and outputs it in the page's ``. **Optional:** online schema generators can auto-generate schema (Video, Article, Product) from a pasted link — paste the resulting code into the ACF field on the post/page. ## Testing schema Use Google's Rich Results Test (or the Structured Data Testing Tool). A green tick means the schema is valid — always test before publishing. ## Important notes - The schema must match the actual visible content on the page. - Never use fake or misleading structured data — it risks a manual penalty. - Visible content (title, author, date) should match what the schema claims. - Use an AI tool to help generate or validate clean JSON-LD for your case. ## Rank Math SEO plugin A separate lecture covers setting up Rank Math for schema support, canonical tags, and meta settings — follow that lecture for the plugin-specific setup. ## Summary - Schema markup improves SEO and helps content stand out visually in search. - The ACF + `functions.php` method adds custom schema manually. - Generate schema from trusted tools or AI, and always test before shipping. - Article, Video, Product, and FAQ schema can each boost ranking and visibility. [^iskills-course-notes]: iSkills SEO course notes, compiled 2025.