Google Shopping custom labels are the main lever you have for segmenting products by performance inside your campaigns. The idea is simple: tag every product as a winner, a loser, or something in between, then build campaign structures that bid accordingly. A product with a 6x ROAS should not share the same bid strategy as one that burned through $200 with zero sales.
The hard part is keeping those labels current. Product performance shifts weekly. A hero SKU in January can turn into dead weight by March. Manually updating spreadsheets and re-uploading supplemental feeds does not scale past a few hundred products.
That is where labeling tools come in. They pull your performance data, classify products by rules you define, and push the results to Merchant Center automatically. This guide compares seven tools that handle product labeling for Google Shopping, from free scripts to full analytics platforms.
Table of Contents
Why Product Labeling Matters
Google Shopping campaigns treat every product equally unless you tell them otherwise. Without labels, your budget spreads across your entire catalog based on Google's algorithm, which optimizes for its revenue, not yours.
Labels let you split products into groups with different bidding strategies. The typical approach is to identify products that convert well and increase their spend, while cutting budget on products that just rack up clicks without sales. Our zero-conversion products guide covers how much budget these underperformers typically consume.
The difference is measurable. Accounts that segment by performance labels generally see ROAS improvements of 15-30% within the first month, mostly from reallocating spend away from products that were never going to convert. It is not a magic fix. It is basic budget hygiene that most accounts skip because maintaining the labels is tedious.
Labels also work with Performance Max campaigns. You can create separate listing groups per label inside your asset groups, effectively controlling which products PMax pushes hardest.
How Product Labeling Works
Every labeling tool follows roughly the same three-step process, regardless of how sophisticated the UI is:
- Pull performance data. The tool reads metrics from Google Ads (clicks, cost, conversions, revenue, ROAS) and sometimes from Merchant Center (price competitiveness, availability, impressions).
- Apply rules. Each product is evaluated against a set of conditions. A simple example: if ROAS is above 3 and clicks are above 20, label it "Hero." If cost is above $50 and conversions are zero, label it "Cut."
- Push to Merchant Center. The tool writes the resulting label to one of the five custom label slots (custom_label_0 through custom_label_4) via a supplemental feed or API connection.
The differences between tools come down to how many conditions you can define, how flexible the rule logic is, and what else the tool does beyond labeling. Some are standalone labelers. Others are full platforms with feed management or analytics built in.
Pro Tip
Google allows five custom label slots per product. If your feed already uses some slots for seasonal tags or margin groups, make sure the labeling tool lets you pick which slot it writes to. Overwriting an existing label with performance data can break other workflows.
1. ProductHero Labelizer
ProductHero is the best-known product labeling tool in the Google Shopping space, largely because of its memorable four-bucket framework: Hero, Sidekick, Villain, and Zombie. The Labelizer classifies every product into one of these buckets based on click volume and ROAS thresholds.
- Label categories: 4 fixed buckets (Hero, Sidekick, Villain, Zombie)
- Conditions: Click threshold and ROAS are the primary classification dimensions
- MC push: Direct connection to Merchant Center
- Additional features: Products AI for title optimization with GPT-based suggestions, PMax Insights dashboards, CSS partnership offering a 20% bidding advantage in EU markets
- Pricing: From EUR 39/month
The simplicity is both the strength and the limitation. You get a working labeling setup in under 10 minutes, but you cannot add your own conditions. If you need labels that factor in price competitiveness, brand, or product type alongside performance, the four fixed buckets will feel constraining.
ProductHero has grown into more than a labeler. The CSS program is a significant draw for EU advertisers, and Products AI adds title optimization with AI-generated suggestions. Worth looking at if you want labeling plus CSS in one package.
2. Optmyzr
Optmyzr is a full Google Ads management platform, and its Smart Product Labeler is one module among many. It uses five performance-based buckets and lets you set threshold rules for each.
- Label categories: 5 configurable buckets
- Conditions: Performance-based rules using Google Ads metrics
- MC push: Direct connection to Merchant Center
- Additional features: Full PPC management suite, bid management, reporting, campaign builder
- Pricing: From approximately $249/month (includes full platform)
The labeler is solid but it is a small part of a much larger platform. If you already use Optmyzr for campaign management, adding product labeling is a natural extension. If labeling is all you need, the price is hard to justify. The reporting features are campaign-centric, not product-centric, so you will not get deep SKU-level analytics from it.
3. Channable (with ProductHero Integration)
Channable is primarily a feed management platform with 2,500+ marketplace integrations. Its product labeling capability comes through a built-in ProductHero integration that uses a similar four-bucket system with different names: Stars, Potentials, Underperformers, and Invisibles.
- Label categories: 4 fixed buckets (Stars, Potentials, Underperformers, Invisibles)
- Conditions: Click volume and ROAS
- MC push: Via Channable's feed rules
- Additional features: Full feed management, rules engine, PPC automation, Insights analytics module
- Pricing: From approximately $69/month plus additional modules
The value here is getting labeling inside your existing feed management workflow. If you already use Channable for feed optimization, the labeling module saves you from adding another tool. The Insights module adds basic analytics, though it is not comparable to dedicated analytics platforms. Our Channable alternatives guide covers when Channable makes sense and when simpler options work better.
4. Shoptimised
Shoptimised is a UK-based product labeling and optimization platform. It stands out from other labeling tools by offering configurable time windows for its performance analysis, ranging from 24 hours to 90 days.
- Label categories: Configurable threshold-based buckets
- Conditions: Performance metrics with adjustable time windows (24h, 7d, 30d, 60d, 90d)
- MC push: Direct connection to Merchant Center
- Additional features: 7-day performance dashboard, product optimization recommendations
- Pricing: From GBP 120/month
The time window flexibility is useful. A product that performed well over 90 days but tanked in the last 7 days is in a different situation than one that has been consistently bad. Most other tools use a single lookback window. The dashboard is basic compared to dedicated analytics tools but covers the essentials.
5. Shopstory
Shopstory is an automation platform for ecommerce that handles product labeling through pre-built workflow templates. Its labeling framework uses four buckets: Overindex, Nearindex, Underindex, and Noindex.
- Label categories: 4 fixed (Overindex, Nearindex, Underindex, Noindex)
- Conditions: Configured via automation flow templates
- MC push: Outputs to Google Sheets, which you connect as a supplemental feed
- Additional features: Broader ecommerce automation workflows, integrations with Shopify and other platforms
- Pricing: From EUR 39/month
The indirect Sheets-based push adds a step compared to tools that write directly to Merchant Center. On the plus side, you get visibility into the label assignments before they reach MC, and you can manually override individual products in the sheet. The automation platform goes beyond labeling with flows for inventory management, ad copy updates, and brand performance monitoring.
6. Flowboost Script (Free)
The Flowboost script is a free Google Ads script with over 5,000 downloads. It is the go-to option for advertisers who want performance-based labeling without paying for a tool. Four buckets: Over-index, Near-index, Under-index, and No-index.
- Label categories: 4 fixed (Over-index, Near-index, Under-index, No-index)
- Conditions: Click threshold and ROAS
- MC push: Outputs to Google Sheets, connected as supplemental feed
- Additional features: None (script only)
- Pricing: Free
The trade-off is maintenance. You need to install and configure the script in your Google Ads account, set up the Google Sheets connection, and connect that sheet as a supplemental feed in Merchant Center. When Google changes its Ads Scripts API, the script can break. Thresholds need manual adjustment as your account scales. There is no UI, no preview, and no analytics. But for a free tool, it does the core job.
7. SKU Analyzer
SKU Analyzer takes a different approach to product labeling. Instead of fixed buckets, it offers a rule builder with 40+ condition fields that you combine with AND logic. You define exactly what "Hero" or "Cut" means for your business.
- Label categories: 8 defaults (Hero, Scale, Cash Cow, Opportunity, Fix Price, Fix Listing, Cut, Monitor) plus unlimited custom labels with your own names and colors
- Conditions: 40+ fields across performance (ROAS, cost, revenue, conversions, CTR, CPC), pricing (price position, price gap, benchmark price), feed attributes (brand, product type, availability), Google signals (click potential), and computed dimensions (performance tier, spend weight). Rules support AND logic and reorderable priority with a fallback label.
- MC push: Direct to Merchant Center via supplemental feed, with auto-recalculation and push during daily refresh
- Additional features: 13-page analytics dashboard covering SKU-level performance, competitive visibility, price benchmarking with daily history, title optimization with before/after impact tracking and A/B testing, feed intelligence with change detection, search term analysis, and PMax channel decomposition
- Pricing: Invite-only
The flexibility gap compared to other tools is significant. Where ProductHero classifies by clicks and ROAS only, SKU Analyzer lets you build rules like "ROAS above 3 AND price position is Competitive AND product type contains Sneakers." You preview the distribution before saving, so you see how many products fall into each label before anything gets pushed.
The bundled analytics is the other differentiator. Most labeling tools stop at the label itself. SKU Analyzer lets you track how each label group performs over time, compare price competitiveness across groups, and see whether label changes actually moved the needle on campaign metrics.
Full Comparison Table
| Tool | Labels | Conditions | MC Push | Analytics | Price |
|---|---|---|---|---|---|
| ProductHero | 4 fixed | Clicks + ROAS | Direct | PMax Insights | From EUR 39/mo |
| Optmyzr | 5 buckets | Performance rules | Direct | Campaign-centric | From ~$249/mo |
| Channable | 4 fixed | Clicks + ROAS | Via feed rules | Basic (Insights) | From ~$69/mo |
| Shoptimised | Configurable | Performance + time windows | Direct | 7-day dashboard | From GBP 120/mo |
| Shopstory | 4 fixed | Via automation flows | Via Sheets | None | From EUR 39/mo |
| Flowboost | 4 fixed | Clicks + ROAS | Via Sheets | None | Free |
| SKU Analyzer | 8 default + custom | 40+ fields, AND logic | Direct, auto-daily | 13-page dashboard | Invite-only |
How to Choose the Right Tool
The right labeling tool depends on what you already have and what else you need beyond labels.
You just want basic labeling and nothing else
Start with the Flowboost Script. It is free, it works, and it will show you whether performance-based labeling makes a difference for your account. If it does, you can upgrade to a paid tool later. If you need something more polished but still affordable, ProductHero at EUR 39/month gives you direct MC push and a clean setup experience.
You already use a feed management tool
If you are on Channable, use their built-in ProductHero integration rather than adding a separate tool. For Feedonomics or other feed platforms without built-in labeling, ProductHero or Flowboost work well as standalone additions.
You manage Google Ads across many features
Optmyzr makes sense if you already use it for bid management, reporting, or campaign creation. The product labeler is a natural fit inside that workflow. Paying $249/month just for labeling does not make sense.
You need flexible rules and analytics
If four fixed buckets feel limiting and you want to factor in pricing data, feed attributes, or Google signals alongside performance metrics, SKU Analyzer is the option with the most granular rule builder. The bundled analytics means you can track how your labeling strategy performs over time without switching between tools. Try the demo dashboard to see the rule builder and analytics in action.
Key Takeaway
Labeling is only as good as the ROAS improvement it delivers. Before committing to a paid tool, test the concept with Flowboost or a manual spreadsheet. Once you confirm that labeled campaigns outperform unlabeled ones, invest in a tool that matches your scale and needs.
Frequently Asked Questions
What is product labeling in Google Shopping?
Product labeling uses Google Merchant Center custom labels (custom_label_0 through custom_label_4) to classify products by performance data such as ROAS, clicks, or conversion rate. Campaigns can then bid differently on each label group. High-ROAS products get more budget while zero-conversion products get reduced bids.
Can I use custom labels with Performance Max campaigns?
Yes. Performance Max listing groups support custom label filters the same way Standard Shopping campaigns do. You can create separate asset groups per label to control budget allocation. Most labeling tools push labels to Merchant Center via supplemental feeds, which works with both campaign types.
What is the cheapest product labeling tool for Google Shopping?
The Flowboost Script is free and handles basic 4-bucket labeling based on clicks and ROAS. It outputs to Google Sheets, which you connect as a supplemental feed. For a paid tool, ProductHero and Shopstory both start at EUR 39 per month.
How often should product labels be updated?
Daily updates are ideal because product performance changes constantly. Most paid labeling tools recalculate labels automatically on a daily schedule. If you use a script-based approach with Google Sheets, weekly updates are the minimum to keep labels relevant. For more on tracking performance changes, see our metrics glossary.
Do I need a labeling tool if I only have 50 products?
With fewer than 50 products, you can manage labels manually in a spreadsheet. Export your shopping performance data, classify products by ROAS and conversion rate, and upload the labels via a supplemental feed CSV. A labeling tool becomes worth it when you have 200+ products, because manually tracking metrics and updating labels becomes error-prone at that scale.
Conclusion
Product labeling is one of the highest-leverage optimizations for Google Shopping. The tools range from a free script to full analytics platforms, and the right choice depends on your catalog size, budget, and how much you need beyond the labels themselves.
For most advertisers, the path looks like this: start with Flowboost or manual labeling to prove the concept, move to ProductHero or Channable's integration when you want direct MC push and less maintenance, and consider a platform like SKU Analyzer or Optmyzr when you need flexible rules, deeper analytics, or both.
Whatever tool you pick, the labels are step one. The real value comes from acting on them: structuring your campaigns around label groups, setting differentiated bid strategies, and tracking whether the segmentation actually improves your ROAS. If you are not measuring the impact, you are just sorting products into buckets for fun.