Check the math on a real order
Draft: 15% off orders over $100. Preview with test order #1042 ($128)
Preview shows the rule matched and $19.20 off, before any shopper sees it.
Tab Promo lets you preview a draft discount against a real order from your store, check it for setup errors, and only then publish it. Every publish is saved as a version, so if a live offer is wrong you can roll back to an earlier version from Publish history. Campaigns can also be scheduled with start and end dates.
See it work

Campaign · quantity tiers
Leather Edit tiers
v3 draftPreview on recent orders
Publish history
v3 is live in your store
Examples
Draft: 15% off orders over $100. Preview with test order #1042 ($128)
Preview shows the rule matched and $19.20 off, before any shopper sees it.
Stack Simulator: replay one order against your active campaigns, or active and scheduled ones
You see which campaigns match that order and get warnings about how they combine.
Active dates: Friday 00:00 to Sunday 23:59
The discount starts and stops on schedule without anyone logging in.
Version 3 went live at 30% instead of 20%. Rollback to this version: version 2
The 20% rules are published again as a new version; the history of version 3 is kept.
Setup
Good to know
Plan: Free — up to 20 promotion orders a month; Starter — $49/month for unlimited orders. Compare plans
FAQ
Yes. Drafts, preview on real orders and the publish check never touch checkout, on any plan. Nothing reaches shoppers until you publish.
Preview and Stack Simulator use real orders from your store (last 60 days). Storefront sandbox uses a sample cart you build, to check the offer messages shoppers will see.
It republishes the rules of an earlier version as a new version. The campaign's current combination settings, schedule and title stay as they are. Nothing in the history is deleted, so you can see what changed and when.
If Tab Promo needs to restore a discount (for example when you switch a campaign off) and finds it was changed in Shopify, it shows the differences instead of overwriting them. You choose: keep the current Shopify settings or overwrite them with the previous settings.
Yes. Set Active dates on the campaign. The schedule is saved with the discount in Shopify.
More with Tab Promo