VSI alternative for shared stock

At a glance

	VSI	OneShelf
How it works	You group variants into one shared inventory. A sale takes from that inventory. A quantity multiplier is available.	One base stock holds the real count. Each linked listing gets its Shopify quantity from it.
Price	$4.99 to $9.99/month, by your Shopify plan. 7-day free trial. No free plan.	Free for up to 10 base stocks. Pro is $9.99/month with no limit and a 30-day free trial.
Online and at POS	The listing does not say.	Yes. A sale online or at the register takes from the same base stock.
Kits and bundles	The listing says it is for composite products and has a quantity multiplier.	Yes. A listing can use several base stocks, with a number per sale such as 2 or 0.5.
Stops a cart before payment	The listing does not mention a checkout check.	Yes, if you turn it on. The checkout rule stops a cart that needs more base stock than you have.
Preview before it changes stock	The listing does not mention a preview or test mode.	Yes. Preview mode writes nothing to Shopify until you press Go live.
Several stores	The listing does not say.	No. OneShelf works inside one store.
On the App Store since	August 30, 2024	October 5, 2026
Rating	2.9 stars from 15 reviews	New. See the listing.

The VSI facts are from its App Store listing on November 4, 2026. "The listing does not say" means that the fact is not on the listing. It does not mean that the app cannot do it.

What reviewers report

These are recent reviews with 1 to 3 stars, from the VSI reviews. One review is one store's experience. Read the full reviews and the developer's replies before you decide.

1 star · February 15, 2026

“It still allowed people to purchase beyond what the allowed inventory that I set.”

2 stars · March 2, 2026

“it want me to turn off track inventory functions, that all the point of sales are not able to check the quantity of the stock”

2 stars · April 29, 2026

“it suddenly started to really bog down our website causing add to cart buttons to load very slowly”

When VSI is the better choice

You have a few groups, and a low fixed price is the most important thing for you.
You only need variants grouped, with no kits that use several items.

When OneShelf fits better

You sell at a Shopify POS register and need the count to show there.
You want a cart that asks for too much to stop before payment.
You want to watch real orders in Preview mode before anything changes.

How to move from VSI to OneShelf

Export your inventory from Shopify. Go to Products, then Export. Keep the file as a record of your numbers today.
Install OneShelf. It starts in Preview mode, so it writes nothing to Shopify.
Create a base stock for each shared item. Count the real shelf. Link the listings that sell it. OneShelf shows each listing's quantity now and after, before you save.
Watch a few real orders in Preview mode. The Activity page shows what OneShelf would take for each order.
Turn off the sync in VSI for the listings you linked. Only one app should set the stock of a listing. OneShelf warns you if a listing changes outside OneShelf.
Press Go live. Then turn on the checkout rule in Settings, if you want a cart that asks for too much to stop before payment.
Uninstall VSI when you are sure. Check a few listings after, and compare them with your export.

If you need help with the move, write to support@oneshelf.app. A real person answers.

Questions

Is OneShelf a good alternative to VSI?

It is if your listings share one real stock in one store, such as blanks, materials, or bulk stock. If you need to share stock between several stores, OneShelf does not do that.

Can I keep VSI installed while I try OneShelf?

Yes. OneShelf starts in Preview mode and writes nothing to Shopify. Before you press Go live, turn off the sync in VSI for the listings you link. Only one app should set the stock of a listing.

Will I lose my stock numbers when I move?

Export your inventory from Shopify first, so you have a record. When you create a base stock, OneShelf shows each listing's quantity now and after, and it changes nothing until you save.

How much does OneShelf cost?

OneShelf is free for up to 10 base stocks. Pro is $9.99/month with no limit, and it has a 30-day free trial.

Try OneShelf in Preview mode

OneShelf gives your listings one base stock. Every sale, online or at the register, takes from that one number. It is free for up to 10 base stocks.

Install on Shopify Open the demo store

The demo store password is shesta.

VSI: Variants Shared Inventory is a product of Addify. OneShelf is not related to Addify. If a fact on this page is wrong or old, write to support@oneshelf.app and we will correct it.