Inventory management is one of those operational fundamentals that does not feel urgent until it goes wrong. Overselling a product that is out of stock damages customer trust and generates refund requests. Carrying too much stock ties up cash and creates storage costs. Running out of a best-seller during a peak period means lost revenue that is difficult to recover. For growing Shopify stores, the gap between what Shopify's built-in tools can handle and what the business actually needs tends to widen quickly.
Shopify's native inventory management covers the basics: tracking stock quantities, setting inventory at multiple locations, and receiving low-stock notifications. For a small store with a straightforward product range and a single sales channel, this may be sufficient. But once you add wholesale, marketplaces, production planning, or even just more than a few hundred SKUs, you need purpose-built tools.
I have helped configure inventory systems for Shopify stores ranging from startup DTC brands to established retailers doing thousands of orders per day. This guide covers the six leading inventory management apps for Shopify, with honest assessments of where each excels and where each falls short. For the broader context of how these tools fit into your technology stack, our guide to ERP integration with Shopify is worth reading alongside this one.
Why inventory management matters for ecommerce
Stockouts cost you revenue directly and indirectly. The direct cost is the lost sale. The indirect cost is the customer who goes to a competitor and may never return. Research consistently shows that 30-40% of customers who encounter an out-of-stock product will buy from a competitor rather than wait for a restock. For brands with strong competitors in the same category, a stockout is effectively a customer acquisition event — for your competitor.
Overstocking is equally problematic, though less immediately visible. Excess inventory ties up working capital that could be invested in marketing, product development, or operations. It generates warehousing costs. And for products with limited shelf lives (food, supplements, seasonal fashion), overstocking creates waste through expiry and markdowns.
The optimal inventory position — enough stock to meet demand without excessive overstock — requires accurate data, good forecasting, and efficient ordering processes. This is what inventory management apps provide: the tools to make informed decisions about what to order, when to order it, and how much to hold.
For stores selling across multiple channels (Shopify, Amazon, eBay, wholesale), inventory synchronisation is critical. Selling the last unit of a product on Amazon while it still shows as available on your Shopify store creates an oversell that requires a cancellation, refund, and apology email. Multi-channel sync apps prevent this by maintaining a single source of truth for stock levels across all platforms.
What to look for in a Shopify inventory app
Purchase order management
The app should allow you to create, send, and track purchase orders to suppliers. Automated PO generation based on reorder points saves time and reduces the risk of stockouts. The ability to track PO status, receive partial shipments, and reconcile received goods against ordered quantities is essential for any store ordering regularly from suppliers.
Demand forecasting
Forecasting uses historical sales data to predict future demand, helping you order the right quantities at the right time. The accuracy of forecasting varies between apps and depends heavily on having sufficient historical data. For seasonal products, the app should account for seasonality patterns rather than using simple linear projections.
Multi-location support
If you hold stock at multiple warehouses, retail locations, or fulfilment centres, the app must track inventory per location and allocate stock to orders based on proximity, availability, or custom rules. Shopify supports multi-location inventory natively, but dedicated apps provide more sophisticated allocation logic.
Multi-channel synchronisation
Stores selling on Amazon, eBay, Etsy, or wholesale platforms need real-time inventory sync across all channels. The app should update stock levels within seconds of a sale on any channel, preventing overselling. It should also support channel-specific stock allocation — reserving a portion of inventory for specific channels.
Reporting and analytics
Inventory reports should cover stock valuation, turnover rates, dead stock identification, and sell-through rates. These reports inform purchasing decisions and help identify products that are tying up capital without generating adequate returns.
Stocky (by Shopify)
Overview
Stocky is Shopify's own inventory management app, included free with Shopify POS Pro and available to all Shopify plans. It provides purchase order management, demand forecasting, stock transfers between locations, inventory analysis, and supplier management. As a first-party app, it integrates natively with Shopify's inventory system.
Pricing
Stocky is free for all Shopify merchants. There are no paid tiers, feature restrictions, or order volume limits.
Strengths
Stocky's greatest advantage is its price: free, with no limitations. The purchase order workflow is straightforward — create POs from suggested reorders, send them to suppliers, and receive stock against them. The demand forecasting uses your Shopify sales data to predict future demand and suggest reorder quantities, which is functional for stores with consistent sales patterns.
The stock transfer feature handles movement between Shopify locations cleanly. Inventory reports cover the basics: stock levels, incoming stock, and inventory analysis by product or supplier. The supplier management module stores supplier information and lead times, which feed into the demand forecasting calculations.
As a Shopify first-party app, there are no integration concerns. Data flows directly between Stocky and your Shopify admin without the latency or sync issues that can affect third-party apps. Updates and compatibility are handled by Shopify's own team.
Weaknesses
Stocky is limited in scope. It does not support multi-channel inventory sync (Amazon, eBay, etc.), barcode scanning for warehouse operations, batch and serial number tracking, or manufacturing and production planning. For stores that need any of these capabilities, Stocky is insufficient.
The demand forecasting is basic compared to dedicated tools. It works adequately for products with steady demand but struggles with seasonal products, new product launches (no historical data), and products with irregular purchase patterns. The forecasting algorithm is a simple moving average rather than a sophisticated model.
Stocky does not offer a mobile app for warehouse operations, which limits its usefulness for physical stock management tasks like receiving deliveries, conducting stock counts, and picking orders.
Best for
Small to mid-sized stores that need basic purchase order management and demand forecasting without additional cost. Stocky is an excellent starting point that covers the fundamentals. You should move to a dedicated tool only when you hit specific limitations that Stocky cannot address.
Katana
Overview
Katana is a cloud-based manufacturing and inventory management platform designed for brands that make, assemble, or customise their own products. Where most inventory apps focus on buy-and-resell workflows, Katana adds production planning, bill of materials (BOM) management, and manufacturing order tracking alongside standard inventory features.
Pricing
Katana offers a Starter plan at $199/month (up to 500 shipped sales orders), Standard at $399/month (up to 2,000 orders), and Professional at $899/month (up to 5,000 orders). There is a 14-day free trial but no free plan. Pricing is per-business, not per-user, which includes unlimited team members.
Strengths
Katana's production planning and BOM management set it apart from every other app on this list. If your brand manufactures, assembles, or processes products, Katana tracks raw materials, components, and finished goods as a unified system. You can see real-time material availability, schedule production runs, and automatically deduct raw materials from inventory when manufacturing orders are completed.
The shop floor interface allows production staff to update manufacturing order status in real time, providing visibility into what is being made, what is waiting, and what is complete. This is genuinely useful for brands with in-house production.
Katana integrates with Shopify, WooCommerce, and major accounting platforms (Xero, QuickBooks). The Shopify integration syncs orders, products, and inventory bi-directionally, keeping both systems in alignment.
Weaknesses
Katana is expensive, especially for stores that do not manufacture their own products. At $199/month for the Starter plan, it costs significantly more than alternatives that provide adequate inventory management for buy-and-resell operations. If you do not need BOMs and production planning, Katana's core differentiator has no value to you.
The multi-channel capabilities are more limited than dedicated multi-channel sync tools like Trunk or SKULabs. While Katana connects to Shopify and a few other platforms, it does not offer the breadth of marketplace integrations that specialist sync apps provide.
The learning curve is moderate. Manufacturing concepts like BOMs, routing, and production scheduling are not intuitive for merchants unfamiliar with production management. Initial setup, particularly for complex products with many components, takes time.
Best for
Brands that manufacture, assemble, or customise their own products in-house. Katana is the clear leader for this use case on Shopify. For brands that buy finished goods from suppliers, other apps offer better value.
inFlow
Overview
inFlow is a comprehensive inventory management system that connects to Shopify alongside other ecommerce platforms. It offers purchase order management, sales order processing, barcode scanning, multi-location management, reporting, and B2B features including showroom and order portals. inFlow positions itself as a mid-market alternative to full ERP systems.
Pricing
inFlow offers an Entrepreneur plan at $110/month (1 team member, 100 sales orders), Small Business at $279/month (5 team members, 1,000 orders), and Mid-Size at $549/month (10 team members, 5,000 orders). There is a 14-day free trial. Pricing includes hosting, updates, and support.
Strengths
inFlow provides a genuinely comprehensive inventory management experience. The purchase order workflow is more detailed than Stocky's, with support for partial receiving, backorder tracking, and supplier performance analytics. The barcode scanning functionality — using a mobile device or dedicated scanner — enables efficient warehouse operations: receiving deliveries, picking orders, and conducting stock counts by scanning rather than manual data entry.
The B2B features are a strong differentiator. inFlow's showroom lets wholesale customers browse your catalogue and place orders through a branded portal, which is valuable for brands with a wholesale channel. The B2B order portal integrates with your inventory, so wholesale orders and DTC orders draw from the same stock pool.
Reporting is detailed, covering inventory valuation (using FIFO, LIFO, or average cost methods), turnover rates, reorder analysis, and profit margins per product. For brands that need to understand the financial performance of their inventory, inFlow's reporting is more sophisticated than most Shopify-native options.
Weaknesses
inFlow is expensive for small stores. The Entrepreneur plan at $110/month with a single user and 100 sales orders is restrictive. Most growing Shopify stores will need the Small Business plan at $279/month, which is a significant operational cost.
The Shopify integration, while functional, is not as seamless as Stocky's native integration. Sync delays can occur during high-volume periods, and initial setup requires careful mapping of products and variants between systems. Data conflicts (where inFlow and Shopify disagree on stock levels) can occur if the sync is disrupted.
The interface is powerful but can feel overwhelming. inFlow tries to be a near-ERP for SMEs, and the feature density reflects that ambition. Stores that need simple inventory tracking may find it overly complex.
Best for
Mid-sized stores that need comprehensive inventory management including B2B capabilities, barcode scanning, and detailed financial reporting. inFlow is the right step before graduating to a full ERP system. For context on when that transition makes sense, see our ERP integration guide.
Trunk
Overview
Trunk is a specialist multi-channel inventory synchronisation app. Where other apps on this list focus on warehouse operations and purchase orders, Trunk focuses specifically on keeping inventory levels accurate across multiple sales channels: Shopify, Amazon, eBay, Etsy, Walmart, and more. It does one thing and does it well.
Pricing
Trunk offers a free plan (up to 25 SKUs, 2 channels), Merchant at $35/month (up to 100 SKUs, unlimited channels), Growth at $55/month (up to 1,000 SKUs), and Enterprise at $99/month (up to 5,000 SKUs). Custom pricing is available for larger catalogues.
Strengths
Trunk's sync speed and reliability are its defining features. Inventory updates propagate across all connected channels within 15 minutes in most cases, with near-instant sync available on higher plans. For stores selling on multiple marketplaces, this speed prevents the overselling that causes cancellations and negative reviews.
The setup is remarkably simple. Connect your channels, map your products (Trunk auto-matches where possible), and the sync begins. There is no warehouse management complexity, no purchase order workflow to learn — just clean, reliable inventory synchronisation.
Trunk also supports inventory buffering, allowing you to reserve a percentage of stock for specific channels. This is useful for brands that want to ensure their own Shopify store always has stock available, even if marketplace inventory runs low. Channel-specific rules add a layer of strategic control.
Weaknesses
Trunk is a sync tool, not an inventory management system. It does not handle purchase orders, demand forecasting, warehouse operations, or stock receiving. If you need these capabilities, Trunk must be paired with another tool (Stocky, inFlow, or an ERP).
The SKU-based pricing means costs can escalate for stores with large product ranges. A store with 3,000 SKUs across variants is on the Enterprise plan at $99/month, and stores with 5,000+ SKUs need custom pricing.
The free plan's 25 SKU limit is useful for testing but not viable for production use by most stores.
Best for
Stores selling on multiple marketplaces that need reliable, fast inventory synchronisation. Trunk is the specialist tool for multi-channel sync, and it pairs well with Stocky or another inventory management app for the operational features it does not provide.
SKULabs
Overview
SKULabs combines multi-channel inventory sync with order management and warehouse operations in a single platform. It is designed for stores that ship high volumes and need barcode-verified picking, packing, and shipping workflows alongside inventory tracking and channel synchronisation.
Pricing
SKULabs offers a Core plan at $299/month (up to 2,000 orders), Standard at $499/month (up to 5,000 orders), and Premium at $699/month (up to 10,000 orders). All plans include unlimited users and channels. There is a free trial available.
Strengths
SKULabs' warehouse management features are strong. Barcode-verified picking reduces shipping errors by ensuring the correct items are packed for each order. The batch picking workflow handles multiple orders simultaneously, significantly improving warehouse throughput. Packing verification confirms that the right items are in the right box before the shipping label is printed.
Multi-channel sync is comprehensive, supporting Shopify, Amazon (FBA and FBM), eBay, Walmart, Etsy, and BigCommerce. Inventory updates are fast and reliable. The order management module consolidates orders from all channels into a single queue for processing.
SKULabs also supports kit and bundle management, automatically deducting component inventory when bundled products are sold. This is useful for stores that sell product bundles without maintaining them as separate physical SKUs.
Weaknesses
SKULabs is expensive. At $299/month for the Core plan, it is one of the most costly options on this list. The pricing is justified for high-volume operations where warehouse efficiency savings exceed the subscription cost, but smaller stores will struggle to see a positive ROI.
The platform is complex. SKULabs is designed for operations teams, not solo merchants. The setup process involves configuring warehouse zones, pick paths, and verification workflows. Stores without dedicated operations staff may find the system overwhelming.
Purchase order management and demand forecasting are less developed than inFlow or Katana. SKULabs' strength is outbound operations (picking, packing, shipping) rather than inbound operations (ordering, receiving, forecasting).
Best for
High-volume stores that ship hundreds or thousands of orders per day and need warehouse management alongside multi-channel sync. SKULabs is the right choice when shipping accuracy and warehouse throughput are your primary operational challenges, as part of your broader Shopify operations strategy.
ShipHero
Overview
ShipHero is a warehouse management system (WMS) that also provides fulfilment services. It offers two products: a software platform for brands that manage their own warehouse, and a full 3PL fulfilment service for brands that want to outsource. The WMS integrates with Shopify and other channels for inventory tracking and order processing.
Pricing
ShipHero's WMS software starts at $499/month for smaller operations. The 3PL fulfilment service pricing is per-order and varies based on volume, item weight, and complexity. Both products include Shopify integration. Custom pricing is available for larger operations.
Strengths
ShipHero's WMS is enterprise-grade. It supports advanced warehouse operations including zone-based picking, wave planning, cycle counting, and automated replenishment from bulk to pick locations. For brands operating warehouses at scale, these features drive significant efficiency improvements.
The 3PL option is unique on this list. If you are at the point where managing your own warehouse is no longer practical or cost-effective, ShipHero can handle fulfilment for you from their network of warehouses. This is a significant operational decision, but having the option within the same platform that handles your inventory provides a smooth transition path.
Multi-channel support is comprehensive, and the Shopify integration handles inventory sync, order import, and fulfilment status updates reliably at high volumes.
Weaknesses
ShipHero is designed for large operations and priced accordingly. At $499/month minimum for the WMS, it is the most expensive option on this list. For stores doing fewer than 500 orders per day, the cost is difficult to justify.
The platform's complexity reflects its enterprise positioning. Setup requires warehouse layout configuration, bin location mapping, and workflow design. This is not a plug-and-play solution — it is a warehouse management system that requires proper implementation.
ShipHero does not focus on purchasing or demand forecasting. Like SKULabs, its strengths are in outbound operations rather than inventory planning.
Best for
Enterprise Shopify stores with their own warehouses or brands considering outsourcing fulfilment to a 3PL. ShipHero is the right choice for operations at scale, not for growing brands still finding their feet with inventory management.
Side-by-side comparison
Price: Stocky is free. Trunk starts at $35/month. inFlow at $110/month. Katana at $199/month. SKULabs at $299/month. ShipHero at $499/month.
Purchase orders: Stocky, Katana, and inFlow handle POs well. SKULabs and ShipHero provide basic PO support. Trunk does not handle POs.
Multi-channel sync: Trunk and SKULabs lead for marketplace synchronisation. ShipHero is strong. Katana and inFlow have limited multi-channel support. Stocky does not sync with external marketplaces.
Warehouse operations: ShipHero and SKULabs lead with barcode scanning, pick/pack workflows, and WMS features. inFlow offers barcode scanning. Katana focuses on manufacturing rather than warehousing. Stocky and Trunk do not provide warehouse operations.
Manufacturing: Katana is the only option with production planning and BOM management. All other apps focus on finished goods inventory.
Best value: Stocky for free basic management. Trunk for affordable multi-channel sync. inFlow for comprehensive mid-market inventory management.
Our recommendations
Just getting started: Stocky. It is free, it covers the basics, and it integrates natively with Shopify. Start here and upgrade only when you hit specific limitations.
Multi-channel sellers: Trunk + Stocky. Use Stocky for purchase orders and forecasting, and Trunk for keeping inventory synchronised across channels. This combination is affordable and effective.
Manufacturers and assemblers: Katana. There is no viable alternative for production-focused inventory management on Shopify.
Mid-market growth: inFlow. It provides comprehensive inventory management with B2B features at a price point below full ERP systems.
High-volume fulfilment: SKULabs or ShipHero. Choose SKULabs for warehouse operations combined with multi-channel sync. Choose ShipHero if you need enterprise WMS or are considering 3PL fulfilment.
When to upgrade to an ERP
Inventory apps serve most Shopify stores well up to a point. But there comes a stage where you need a unified system that handles inventory, accounting, CRM, purchasing, and potentially manufacturing in a single platform. That is when an ERP (Enterprise Resource Planning) system makes sense.
Common signals that you have outgrown inventory apps include: you are spending significant time reconciling data between separate systems, your accounting team needs inventory data in a format your inventory app cannot produce, you are managing supplier relationships and purchase orders across multiple disconnected tools, or your operation has grown to the point where the total cost of separate apps approaches the cost of an ERP.
For most Shopify stores, this transition point comes somewhere between 5,000 and 15,000 orders per month, though it varies based on operational complexity. Our ERP integration guide covers the major ERP options for Shopify and the integration approaches available. If you need help assessing whether your store is ready for an ERP or can continue scaling with inventory apps, auditing your current app stack is a good first step.
Good inventory management is invisible to customers — they simply receive what they ordered, on time. Poor inventory management creates stockouts, overselling, and delays that erode trust. The app you choose should match your current operational complexity while providing room to grow. If you need help choosing and implementing the right inventory system for your Shopify store, get in touch. We configure inventory solutions as part of our Shopify development services.