Stop retyping product data. Push your Shopify catalog to OnBuy automatically with synced listings and variants.
TL;DR: Manually recreating your Shopify product catalog on OnBuy means retyping titles, descriptions, prices, and variant details for every single product. With hundreds of SKUs, that’s days of work and a guaranteed source of errors. A Shopify OnBuy integration pushes your existing product data to OnBuy automatically.
Your Shopify store has 400 products. Each product has a title, description, 4-5 images, pricing, weight, and a barcode. Some have variants: sizes, colours, materials. That’s easily 1,200 individual SKUs with unique prices and stock levels.
Now you want to sell on OnBuy. Without automation, here’s your to-do list:
That’s not a task. That’s a punishment. And the real problem isn’t even the initial listing. It’s what happens next.
Products change. Prices go up. Descriptions get rewritten. New images replace old ones. Variants get added or discontinued. Every time you update something in Shopify, you need to remember to make the same change on OnBuy.
Forget to update a price on OnBuy after changing it in Shopify? You’re now selling at the wrong margin. Forget to mark a variant as out of stock? You’ll oversell and have to cancel the order, which damages your seller rating.
Manual listing isn’t just slow at the start. It creates an ongoing operational burden that grows with every product you add.
OnBuy listings require specific data fields. Here’s what maps from your Shopify catalog:
| OnBuy Field | Shopify Source | Notes |
|---|---|---|
| Product title | Product title | Direct mapping |
| Description | Product description (HTML) | OnBuy accepts HTML formatting |
| GTIN/Barcode | Variant barcode | Required. OnBuy won’t list without it |
| Price | Variant price | Can be synced or set independently |
| Stock quantity | Inventory level | Should update in real time |
| Images | Product images | Multiple images supported |
| Variants | Shopify variants | Size, colour, etc. |
| Weight | Variant weight | Used for shipping estimates |
Most of this data already lives in your Shopify admin. The question is how to get it across to OnBuy without retyping it.
This trips up more sellers than anything else. OnBuy requires a valid GTIN (barcode) for every product listing. No barcode, no listing. There’s no workaround.
If your Shopify products already have barcodes assigned (EAN-13, UPC, or ISBN), you’re set. The integration uses these to create and match OnBuy listings.
If your products don’t have barcodes, you’ll need to add them before listing on OnBuy. This is a hard requirement from the marketplace, not a limitation of any integration tool. Check your Shopify product pages: the barcode field is under each variant in the inventory section. Our complete seller guide covers all OnBuy requirements in detail.
An OnBuy Shopify integration replaces the entire manual process. Here’s the flow:
Step 4 is the part that matters long-term. The initial listing is a one-time effort either way. Keeping two platforms in sync forever is where automation pays for itself.
Variants are where manual listing really breaks down. A t-shirt in 4 sizes and 3 colours is 12 variants. Each needs its own barcode, price, and stock count on OnBuy. A shoe in 8 sizes is 8 variants. Multiply that across your catalog and you’re looking at thousands of individual data points.
An integration handles variant mapping automatically. Each Shopify variant with a barcode creates a corresponding OnBuy listing entry. Stock levels sync at the variant level, so selling out of “Medium / Black” on Shopify immediately shows that specific variant as unavailable on OnBuy, while other sizes and colours stay live.
Even if you decide to list manually (maybe you only have 15 products), doing it product by product through OnBuy’s seller panel is slow. OnBuy does support CSV uploads for bulk listing, which is faster than manual entry but still requires you to format a spreadsheet, map columns correctly, and re-export every time something changes.
The middle ground: CSV export from Shopify, reformat for OnBuy, upload. It works for the initial push. It falls apart for ongoing updates because you’d need to re-export and re-upload every time you change a price or add a product. That’s not sync. That’s a recurring export job.
A direct integration skips the spreadsheet entirely. Shopify is the source. OnBuy gets the data. Changes flow automatically.
If you’ve already listed some products on OnBuy manually, an integration can match them to your Shopify catalog using barcodes. The GTIN is the unique identifier on both platforms. When the integration sees a Shopify product with the same barcode as an existing OnBuy listing, it links them instead of creating a duplicate.
This means you don’t have to start from scratch even if you’ve already done some manual work. The integration picks up where you left off.
Product listing is just one piece of selling on OnBuy. Once products are live, you need order sync to pull OnBuy sales into Shopify and inventory sync to prevent overselling. All three work together: products go out, orders come in, stock stays accurate.
If you’re also considering which marketplace to start with, our OnBuy vs Amazon comparison breaks down fees, policies, and trade-offs. And if you’re interested in reaching European customers, OnBuy is now live in 12 EU countries.
Ready to skip the manual work? Check out the Shopify OnBuy integration.