Extensiv (formerly 3PL Central) and StockFlow solve different problems that both get called "inventory software." Extensiv is a warehouse management system purpose-built for third-party logistics (3PL) and fourth-party logistics (4PL) providers businesses that store and ship inventory on behalf of other companies and need to bill each client for the space and labor used. StockFlow is inventory-first software: it tracks a business's own stock and can also record a client as the owner of each product, so a smaller 3PL can keep client stock separate and report it per client, without an automated billing layer or client portal.
If you are evaluating both, the fastest filter is this: do you need to invoice separate client accounts for warehouse activity? If yes, a 3PL-specific platform like Extensiv is built for that from the ground up. If no, you are simply tracking your own stock across one or more locations, that entire layer of Extensiv's feature set goes unused, and a leaner, inventory-first tool is usually the better cost-to-value fit.
Feature-by-Feature Table
| Capability | StockFlow | Extensiv |
|---|---|---|
| Entry pricing model | Free starting path for SMB inventory teams | Entry-tier 3PL WMS plans commonly start around $599/month |
| Target market | SMBs, distributors, ecommerce and small 3PLs; own stock or client stock | 3PL and 4PL warehouse operators billing multiple client accounts |
| Client stock separation | Client (stock owner) per product; clients can share bins; Client Inventory report per client and location | Separate client accounts within the 3PL platform |
| Core focus | Inventory accuracy, barcode receiving/picking, purchase orders | Multi-client warehouse operations: billing, client portals, network visibility |
| Client billing | No automated billing; per-client stock, locations, receipts and shipments export to CSV as invoice input | Automated client billing based on storage and pick activity (Billing Manager) |
| Client portal | No client login | Client-facing portal into their own stock |
| Multi-warehouse | Multi-location support with stock transfers | Multi-warehouse and multi-client network management (Network Manager) |
| Integrations | Core ecommerce, accounting, and shipping integrations | Broad integration marketplace covering many carriers and sales channels |
| Best fit | A business managing its own stock across locations | A 3PL/4PL provider managing inventory on behalf of multiple client brands |
Pricing and Cost Reality
Entry-tier 3PL warehouse management plans, including Extensiv, commonly start around $599 per month, pricing built around 3PL-specific features like client billing, client portals, and multi-client network management. StockFlow starts free for businesses that just need accurate, barcode-driven stock control without that client-billing layer.
If you are a 3PL provider, Extensiv's pricing reflects real functionality you will use daily. If you are not a 3PL, you run your own retail, distribution, or manufacturing inventory, that pricing is paying for a feature set built for a different business model.
StockFlow Pros / Cons
- Pros: Free starting path for a single business tracking its own inventory.
- Pros: Fast rollout, barcode receiving, counts, and transfers without a 3PL onboarding process.
- Pros: Client stock separation and per-client inventory reports for smaller 3PLs, with CSV export for invoicing.
- Cons: No automated client billing or client portal, which larger 3PL/4PL operators rely on.
- Cons: Fewer carrier-specific 3PL integrations than a dedicated 3PL WMS.
Extensiv Pros / Cons
- Pros: Purpose-built billing, client portal, and multi-client network management for 3PL operators.
- Pros: Broad integration marketplace across carriers and sales channels.
- Cons: Higher entry price built around 3PL features a single business won't use.
- Cons: Overkill if you are managing only your own stock, not client accounts.
Who Should Choose Which
Choose StockFlow when you run your own business, retail, wholesale, ecommerce, or light manufacturing, and need accurate, barcode-driven stock control across one or more locations without paying for 3PL-specific tooling you won't use. It also fits a smaller 3PL that stores stock for a handful of clients and needs it separated and reported per client; see 3PL inventory management software.
Choose Extensiv when you operate a 3PL or 4PL business: you store and fulfill inventory on behalf of client brands, need to bill each client for storage and activity, and want a client-facing portal into their own stock.
Related comparisons: StockFlow vs Zenventory, StockFlow vs Cin7, and StockFlow vs ShipStation. Warehouse guide: warehouse management system process flow.
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What our customers say
“Super Kind! Quick replies from their support and very easy fixes, changed the dashboard a bit and customized it. Also gave me 450 items extra on the free plan just for me. Highly recommend and again great service!”
“Best customer service! Stockflow's customer support is fast and extremely helpful. They assisted me with customization of the software to improve my experience as a user.”