In Shopping ads you don't write keywords or headlines. Your product feed does that job. Google reads your titles, descriptions, categories, identifiers and images to decide which searches each product is relevant for and how it should look. Two stores selling the same item at the same price can get very different results purely because of feed quality.
That makes shopping feed optimization one of the highest-leverage tasks in ecommerce advertising. Better data means more relevant impressions, higher click-through rates and cleaner campaign structure, and the same improvements help free listings and Google's AI shopping surfaces too.
This guide goes attribute by attribute through what to optimise, shows title formulas by category, explains how to use rules and supplemental data to fix feeds without touching your store, and covers how to use custom labels to bid smarter.
Key Takeaways
- Your feed is your targeting and your ad copy; titles and images matter most for performance.
- Front-load titles with what shoppers search: brand, product type and key attributes.
- Accurate GTINs, categories and variant data help Google match products to the right searches.
- Use attribute rules and supplemental data sources to improve feeds without editing your store.
- Custom labels let you group products by margin, seasonality or performance for smarter bidding.
Approval vs optimisation
Getting products approved is the minimum. If you're still setting up the account or fixing disapprovals, start with our Google Merchant Center guide. Optimisation goes further: it improves how often products appear for the right searches and how many shoppers click.
Google's product data specification is the rulebook. It's also explicit that descriptions should "Include only information about the product." (Product data specification), so promotional text, shipping offers and company boilerplate belong elsewhere.
Attribute-by-attribute optimisation
| Attribute | Limit or rule (Google) | Optimisation focus |
|---|---|---|
title | Up to 150 characters | Front-load brand, product type and key attributes; include variant details |
description | Up to 5,000 characters; product information only | Features, materials, dimensions, use cases, compatibility |
image_link / additional_image_link | No watermarks, promo text or placeholders; up to 10 additional images | Clear main image; lifestyle and detail shots as additional images |
gtin | Must pass GS1 validation; wrong GTINs cause disapproval | Use real manufacturer barcodes; never invent one |
google_product_category | One category from Google's taxonomy | Choose the most specific relevant category |
product_type | Up to 750 characters; full path recommended | Mirror your store's category tree for reporting and campaign structure |
item_group_id | Required for variants in several countries and for all variants in free listings | Use the parent SKU; keep it stable |
product_highlight | 2–100 highlights, up to 150 characters each | Short, scannable benefits and specs |
sale_price | Submit alongside price | Use for genuine sales instead of "SALE" in titles |
custom_label_0–4 | Optional; not shown to shoppers | Margin, seasonality, best-seller or price-band labels |
Source for limits: Google's product data specification. Note that from 31 January 2027 Google will require product images of at least 500 × 500 pixels.
Writing better product titles
Titles have the largest influence on which searches a product matches and whether shoppers click.
“Put the most important details first.”
— Google Merchant Center Help, Title [title]
Google's title guidance says shoppers typically see only around the first 70 characters, depending on screen size, so the start of the title does most of the work. Its examples combine brand, material, gender, product type, colour and size, such as a men's organic cotton T-shirt with colour and size at the end.
| Category | Example title structure |
|---|---|
| Apparel | Brand + gender + product type + material/style + colour + size |
| Electronics | Brand + product line + model + key spec (storage, screen size) + colour |
| Home and furniture | Brand + product type + material + dimensions + colour |
| Beauty | Brand + product line + product type + size/volume + shade or scent |
| Spare parts | Brand + part type + compatible models + part number |
Leave out prices, "free shipping", time-limited wording, all caps and symbols; Google tells merchants to submit those details through their own attributes. Use search terms data from your campaigns to see which words shoppers actually use, and add missing ones where they're accurate. Our guide to the Google Ads search terms report shows how.
Fixing your feed without editing your store: step by step
Many stores can't easily change product titles on the website, or don't want to. Merchant Center lets you transform data on Google's side.
- Export your current feed and sort products by impressions or revenue so you work on what matters first.
- Audit for gaps: missing GTINs, brands, colours, sizes, categories and thin titles.
- Create attribute rules in Merchant Center to rebuild titles from other attributes (for example, brand + product type + colour + size). Google lets you define custom attributes for use in these rules (attribute rules help).
- Add a supplemental data source, such as a Google Sheet keyed by product ID, for fields your platform can't export: custom labels, highlights or improved titles.
- Check that changes still match the landing page. Titles must accurately describe the product and match your page.
- Keep price and availability in sync. Schedule feed or API updates right after website price changes; Google treats mismatches as critical errors, even if automatic item updates correct some prices (Mismatched price help).
- Measure impact in Merchant Center's performance report and your campaigns, comparing clicks and conversions before and after.
Using custom labels for smarter bidding
Custom labels don't affect what shoppers see, but they make campaign structure much more useful. Common schemes include:
- Margin band (high, medium, low) so you can set different ROAS targets. See our guide to ROAS.
- Seasonality (summer, winter, holiday) to push products at the right time; useful for holiday marketing.
- Performance tier (best-seller, average, zombie) to give low-impression products their own budget.
- Price band to control spend on low-value items.
- New arrivals to give launches visibility before they have sales history.
These labels plug straight into standard Shopping and Performance Max listing groups. Our Google Shopping ads guide covers campaign structure.
Keep the feed and website consistent
Google cross-checks your feed against your pages. Google Search Central notes that structured data can help Merchant Center verify feeds against your site (Share your product data with Google). Add accurate Product markup, as explained in our merchant listing schema guide, and keep on-page prices, stock and shipping identical to the feed.
Common mistakes
- Keyword stuffing titles. Repetition and unrelated terms reduce relevance and can breach policies.
- Promotional text in titles or images. Use
sale_priceand promotions instead. - Guessing GTINs. Google's advice is not to provide one when in doubt.
- Generic categories. "Clothing" helps far less than a specific taxonomy path.
- Ignoring variants. Missing
item_group_id, colour or size data hides variants from filtered searches. - Optimising once. Feeds drift as products, prices and search behaviour change; review monthly.
Related Guides
- Ecommerce SEO Checklist for Online Stores
- Ecommerce Site Structure for SEO: How to Organise Your Store
- Out-of-Stock and Discontinued Products: SEO Best Practices
- Link Building for Ecommerce Sites
Frequently Asked Questions
What is shopping feed optimization?
It's the process of improving the product data you send to Google Merchant Center, such as titles, images, categories and identifiers, so products show for more relevant searches and earn more clicks.
What is the most important attribute to optimise?
Titles usually have the biggest impact, followed by images. Accurate GTINs and categories also help Google match products to searches.
How long can Google Shopping titles be?
Up to 150 characters, but shoppers typically see only around the first 70, so put the most important details first.
Can I change feed titles without changing my website?
Yes. Use attribute rules or a supplemental data source in Merchant Center, but make sure titles still accurately describe the product and match the landing page.
What are custom labels used for?
Custom labels let you group products by your own criteria, such as margin, season or performance, so you can structure campaigns and bids. Shoppers don't see them.
Better data, better results
Shopping feed optimisation is unglamorous work, but it lifts every Google shopping channel at once: paid Shopping, Performance Max, free listings and AI-powered surfaces. Start with titles and images on your top products, close data gaps, then use custom labels to bid smarter. For hands-on help, see our PPC management services and ecommerce SEO services, read our guide to free product listings, or request a quote.
References
- Product data specification – Google Merchant Center Help
- Title [title] – Google Merchant Center Help
- How to fix: Automatic updates: Mismatched price – Google Merchant Center Help
- Set up custom attributes to use in attribute rules – Google Merchant Center Help
- Share Your Product Data With Google – Google Search Central
- Product Listing Ads: What They Are and How to Use Them – Semrush Blog
