The Diagnostics tab in Merchant Center is the most important page in the platform that most store owners barely look at. It is where feed errors accumulate, disapprovals are catalogued, and the gap between your submitted product count and your active product count becomes visible.
Learning to read Diagnostics efficiently — and act on what you find — has a direct impact on how many products are actually eligible to show in Shopping.
Getting to Diagnostics
In Merchant Center, go to Products, Diagnostics. You will see three tabs: Items, Feeds, and Account.
Each tab surfaces a different level of issue. Start with Account, then move to Items.
The Account Tab
The Account tab shows issues that affect your entire Merchant Center account, not just specific products. Account-level issues are the highest priority because they can suppress all products, not just the ones with individual errors.
Common account-level issues:
Website not claimed or verified — if your website verification lapses (can happen after a domain transfer or CMS migration), all products in the account become ineligible. Fix: re-verify and re-claim your website.
Business information incomplete — missing address, unverified phone number, or other required business details that Google uses to validate your account legitimacy.
Policy violations at account level — a determination that your account has systematic policy issues, not just product-level errors. This is more serious and typically requires submitting a reinstatement request after fixing the root cause.
Shipping not configured — no shipping services set up, which makes all products ineligible to show regardless of feed quality.
If anything appears in the Account tab, fix those issues before spending time on item-level errors. A single account-level issue can render all your product-level fixes irrelevant.
The Items Tab
The Items tab shows product-level errors and warnings broken down by type. This is where most of your diagnostic work happens.
Reading the Item Status Overview
At the top of the Items tab, you will see a summary of your product status:
- Active — products currently eligible to show in Shopping
- Pending — products submitted but not yet processed by Google
- Disapproved — products with errors that make them ineligible to show
- Expiring — products approaching the 30-day expiration window
The ratio of Active to total submitted is your approval rate. An approval rate below 90% means a meaningful portion of your catalog is invisible to Shopping users. Below 80% and you have a systematic feed quality problem worth prioritizing.
Errors vs Warnings
Items tab issues are split into errors and warnings.
Errors cause disapprovals. Products with errors cannot show until the error is resolved. These are always higher priority than warnings.
Warnings do not cause disapprovals but may limit how or where products appear. Missing GTINs on branded products, for example, generate a warning rather than a hard error — the product can still show, but with reduced visibility and quality signals.
The Issue Detail View
Click any error or warning type to see the specific products affected and the exact issue detail.
Each issue shows:
- The number of products affected
- The specific error reason and what it means
- A link to Google’s documentation for that issue
- A sample of affected product IDs
The sample is important — click through to individual affected products to see the exact data Google is reading. Sometimes the issue is clear from the error name (missing_image) and sometimes you need to look at the actual product data to understand why the error is appearing on a product that looks correct in your feed.
Prioritizing What to Fix First
Not all errors deserve equal attention. Prioritize based on two factors: the severity of the error and the commercial importance of the affected products.
Fix first: errors affecting high-revenue products. If your top 20 products by revenue all have a specific error, fixing that error has more impact on campaign performance than fixing a different error affecting low-margin products.
Fix first: high-volume errors that are easy to fix. An error affecting 500 products that can be resolved with a single feed change is higher ROI than an error affecting 10 products that requires manual review of each one.
Fix next: warnings on branded products. Missing GTIN warnings on branded products should be addressed — GTINs improve product quality signals and Shopping visibility for branded searches.
Fix last: warnings on unbranded or private label products. For products where no GTIN exists, set identifier_exists: false and move on.
The Feeds Tab
The Feeds tab shows the status of your feed files or data connections rather than individual products.
Here you can see:
- When each feed was last fetched or uploaded
- How many products were processed in the last fetch
- Whether the fetch was successful or encountered errors
- The feed processing history
Check for fetch failures. A feed that has not fetched successfully in 24 hours is silently falling out of date. Prices, availability, and new products are not updating. A feed that has not fetched in 30 days will cause all products to expire.
Check the product count trend. If the processed product count in your feed drops suddenly — from 3,000 to 2,400 products across fetches — something changed in your feed generation. This could be a platform error, a filter being applied incorrectly, or products being removed from the feed source.
Check the fetch schedule. Verify the fetch frequency and timing are appropriate for your store’s update cadence. If your prices update at midnight, a 1am fetch captures those updates. A 6pm fetch misses them by 18 hours.
Using Diagnostics as a Recurring Audit
Diagnostics is most valuable as a recurring monitoring tool, not just a one-time setup check. Errors accumulate over time as products change, new inventory is added, and edge cases in your feed generation create unexpected values.
A practical weekly Diagnostics review:
- Check the Account tab for any new account-level issues
- Note the active product count and compare to the previous week — any drop needs an explanation
- Review the top five errors by product volume affected
- Identify any new errors that were not present last week
- For new errors, find affected products and trace the root cause in the feed
Build this into your weekly campaign review rather than treating it as a separate task. Feed health is part of campaign performance — a declining approval rate will eventually show up in Shopping impression share and conversion volume.
The 30-Day Expiration Rule
Products in Merchant Center expire 30 days after their last successful update. An expired product stops showing in Shopping until it is refreshed.
Most automatic feed setups prevent this — if your feed fetches daily, products are refreshed daily. But if your feed fetch fails for an extended period, or you are managing products manually without regular updates, expiration can quietly take products offline.
Check the Expiring filter in Products, All Products periodically. Products approaching expiration appear here before they actually expire, giving you time to trigger a feed refresh before they go dark.
If you see a large batch of products expiring on the same date, it usually means a feed fetch failure from 30 days ago. Resolve the underlying fetch issue and trigger a manual refresh.
Exporting Diagnostics Data
For accounts with large catalogs or systematic feed issues, export your diagnostics data for deeper analysis. In the Items tab, click Download report to get a CSV of all issues with affected product IDs.
Import this into a spreadsheet, join it with your product catalog data, and cross-reference with revenue or campaign performance data. This tells you which errors are actually hurting revenue — a missing GTIN on a $5 accessory is less urgent than the same error on your bestselling product.
The export also makes it practical to hand off feed fix tasks to a developer or a team member — the CSV gives them the specific product IDs and error details to work with.
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