What structured data is
When a person reads a product page, they can tell which number is the price and which text is the name. A search engine has to infer it. Structured data is a standard way of labeling those details in a form machines can read directly. It sits in the page’s code and is invisible to shoppers, though it should describe what they can see.
Several formats exist. The most common is a block of text in a format called JSON-LD, which is kept separate from the visible page. Many store systems and plugins can generate it automatically, so you may not need to write any by hand.
The labels themselves come from a shared vocabulary, widely used across the web, that defines types such as a product, an offer and a review, and the properties each can have.
What product markup describes
A basic product description typically includes:
- Name. The product title as shown on the page.
- Image. One or more pictures of the item.
- Description. A short summary of the product.
- Brand. The maker or label, if applicable.
- Identifiers. Codes such as a SKU or a global trade item number, where you have them.
- Offer. The price, the currency, whether the item is in stock, and the condition (new, used).
- Ratings and reviews. The average rating and the number of reviews, if you collect genuine customer reviews on the page.
For variants such as sizes and colors, each can be described with its own details, though the best way to do so depends on how your catalog handles product variants.
Other types of markup are also useful for stores: the organization behind the site, breadcrumbs showing page location, and return policy details. Search engines document which properties they support, and the guidance changes over time, so consult their current documentation.
How it can help
Search engines may use structured data to understand a page more accurately and to show extra information in a listing, sometimes called a rich result. A listing might include price, availability or star ratings beneath the title. These can make a result more informative and may encourage clicks.
Important limits:
- Markup does not directly guarantee higher rankings.
- Eligibility is not a promise of display. Engines decide whether and when to show enhanced listings.
- Their rules change, and features that appear today may be altered or removed.
Treat structured data as clear communication, not a trick.
Rules to follow
Search engines publish guidelines, and violating them can lead to markup being ignored or to a manual action against the site. The general principles are:
- Mark up only what is visible. The price in the markup must match the price on the page. Do not label content that shoppers cannot see.
- Be accurate. Availability, price and currency should reflect reality and be updated when they change.
- Use genuine reviews. Do not write ratings yourself or mark up reviews copied from elsewhere. Ratings that come from real customers on your own page are fine. Fabricated ones can bring penalties and also risk breaching consumer protection rules, so see the general guidance on consumer rights.
- Mark up the main product only. On a page listing many items, such as a category, each should not be described as if it were the page’s central product, unless the guidelines for that case say otherwise.
- Keep it current. Stale markup that conflicts with the page becomes a liability.
Adding it to your store
Options, from easiest to most hands-on:
- Built-in support. Many store builders output basic product markup automatically. Check what yours produces before adding more, since duplicating it can cause conflicts.
- Extensions or plugins. These can generate fuller markup. Choose carefully, keep them updated and watch for double output.
- Manual or custom code. Developers can insert JSON-LD through the page templates, filling in values from your catalog so they stay in sync.
Whichever route you choose, base markup on your product data rather than typing values separately, so a price change on the page changes the markup too.
Testing and monitoring
Search engines offer free tools that check markup and show whether a page is eligible for enhanced results. Paste an address or code snippet and review errors and warnings. Errors usually need fixing; warnings often mark optional properties.
After deployment, the webmaster tools your search engine provides often include reports on detected markup and problems across the site. Check them periodically, especially after theme changes or platform updates, which can quietly break markup. Note that recrawling takes time, so improvements are not immediate.
Common mistakes
- Price or availability in markup differing from the page.
- Missing or incorrect currency.
- Markup on pages that are not about a single product.
- Duplicate blocks from both the theme and an extension.
- Self-written ratings.
- Never testing after changes.
Where it fits
Start with solid pages: useful product descriptions, clear images and accessible pages. Structured data is a refinement that helps machines read what is already good. It deserves a place on your list after the basics of crawling, content and structure are sound, and it is worth checking again whenever your store or the engines’ guidance changes.