Attribute Rules
Merchant Center Attribute Rules: the full guide
Attribute Rules are Google Merchant Center’s way of rewriting product attributes: instead of editing your feed by hand, you define “what condition” + “what operation”, and Google applies it automatically. This guide covers the 6 core operations and shows you how to turn a plain-English sentence into a verifiable rule with RuleGen.
The 6 supported operations
The MVP is strictly limited to the operations below; anything outside this range returns “Unsupported operation”, so it never invents an operation that doesn’t exist.
| Operation | Description | Example |
|---|---|---|
Set To set | Replace the target attribute’s current value entirely with a specified value. | Set condition = "new" — sets the condition attribute directly to new. |
Prepend prepend | Add the specified content to the very front of the target attribute’s existing value. | Prepend brand — the title becomes “Nike Air Max 270”. |
Append append | Add the specified content to the very end of the target attribute’s existing value. | Append color — appends “Red” to the end of the title. |
Find & Replace replace | Find a substring in the target attribute and replace it (MVP supports exact / case-insensitive / global replace). | Replace "women" → "womens". |
Clear clear | Empty the target attribute (set to blank); later rules no longer act on it. | If brand = "N/A" → Clear brand. |
Conditional Logic condition | Control when the operation runs: AND / OR combinations of equals, not equals, contains, does not contain, is empty, is not empty. | When brand is not empty AND title does not contain brand → Prepend. |
Try RuleGen — generate rules in plain English
Describe the result you want (e.g. “if the title has no brand, prepend the brand”), and RuleGen produces a structured rule with a local Before/After simulation — confirm the behavior before you lift a finger.
Open the RuleGen builder →Frequently asked questions
What are Merchant Center Attribute Rules?
Attribute Rules are a data-transformation mechanism in Google Merchant Center: on the product data you submit, they rewrite a given attribute’s value (title, brand, description, …) automatically based on conditions you define. They don’t auto-publish — after saving a rule as a draft you can test it, then apply it.
What’s the difference between Property Condition and Condition?
Condition decides when a rule fires — e.g. “brand is not empty AND title does not contain brand”. Property Condition is Google’s newer attribute-condition syntax; semantically equivalent but expressed differently. This tool’s MVP covers the 6 core operations and AND logic; OR and more complex expressions are P1 scope.
What’s the core difference between Set To and Prepend/Append?
Set To overwrites the entire attribute value; Prepend / Append only insert new content at the start or end, keeping the original. For example, Set To "Nike" turns the title into just "Nike", while Prepend "Nike" becomes "Nike original title".
After a Clear, do later rules still act on that attribute?
No. Per Google’s semantics, Clear removes the attribute’s value; once cleared on that product, later rules no longer act on it. So place Clear at the end of a chain, or handle it separately from other attributes.
Why might local simulation differ from the official Merchant Center result?
The local simulator is a deterministic TypeScript engine that computes Before/After row by row on the sample data you provide. It proves the rule behaves correctly on your examples, but Google also applies extra constraints such as attribute whitelists and data precedence — so "Ready to apply" means it passed local validation and simulation, not that Google will necessarily accept it.