Find out which slow page is costing your store the most
SIUX Studio matches real-visitor Core Web Vitals with your orders, so every product, collection and checkout page comes with a monthly price and a clear first fix.
Your own sales dataDelivered in 48 hMoney-back guarantee
What to fix first
yourstore.com
Sample report, ranked by money at stake each month
- 1/products/best-sellerProduct photo is 2.4 MB$1,200/mo
- 2/collections/newFilters react in 420 ms$740/mo
- 3/cartShipping banner shifts the layout$310/mo
Fix #1 alone is worth about $14,400 a year.
The driver to watch
For a store, the driver is how fast the product photo shows up
Shoppers decide on the product page, and the product photo is usually the largest thing on it. On a phone, a heavy photo or a slow theme is the difference between a look and an add to cart.
What usually causes it
- Product photos uploaded at full size, not resized or in a modern format
- Theme and app scripts loading before the image
- Slow server responses on uncached product pages
LCPLargest Contentful Paint
4.1 s
/products/best-seller on mobile, in a sample report
+9.1%more shoppers went from product page to add to basket when retail sites got 0.1 s faster.
Source: Deloitte × GoogleOnline stores
Where speed costs a store money
Three kinds of page carry most of a store’s revenue. These are the problems that slow each of them down.
/products/…LCP
Product pages
The main photo is the largest thing on the page. A heavy image or a slow theme delays the moment shoppers see what they came for.
/collections/…INP
Collection pages
Filters, sorting and quick-add buttons all run on scripts. When apps pile up, every tap has to wait.
/cartCLS
Cart and checkout
Upsell widgets, shipping banners and payment buttons that load last push the layout around just as people are about to pay.
What we measure
Five signals, and what each one costs you
Speed metrics on their own are trivia. Each one below is tracked per page and tied to the sales that page brings in.
0.1s
Faster on mobile was enough to lift retail conversions by 8.4% in the Deloitte × Google study.
Read the Core Web Vitals guideLargest Contentful PaintWhen the main image or headline shows up.Good ≤ 2.5 s
Interaction to Next PaintHow fast the page reacts to a tap.Good ≤ 200 ms
Cumulative Layout ShiftHow much the page jumps while loading.Good ≤ 0.1
Time to First ByteHow long the server takes to answer.Good ≤ 0.8 s
Revenue per pageSales matched to the page that made them.Via webhook
Calculator
What a faster store is worth to you
Put in rough numbers from your store admin. The assumption behind every figure is spelled out below.
Extra annual revenue at 4.1 s
Drag the slider to the right to see what a faster page earns.
- Revenue today
- $46,800/mo
- Sales per month today
- 720
Assumes, for every 0.1 s faster, +1% more conversions and +0.4% more visitors (fewer people give up before the page loads, plus a light Google ranking boost), both halved below 2.5 s, with visitors capped at +10%. Deloitte × Google measured +8.4% conversions for retail from 0.1 s, so this is conservative. Your real report uses your own visitors and orders.
The research behind the maths
More retail conversions from a site just 0.1 s faster on mobile.
+8.4% conversionsDeloitte × Google
Higher average order value in the same study, same 0.1 s.
+9.2% order valueDeloitte × Google
More sales at Vodafone after improving LCP by 31%.
+8% salesweb.dev
Better mobile conversion at Lazada with a 3× faster LCP.
+16.9% mobileweb.dev
Ask the report
Questions the report answers for a store
Sample answers, from the kind of data a connected site produces.
Which products lose the most money to speed?
Your top 20 products bring in 70% of revenue. Six of them take over 4 s on mobile, with about $2,100 a month at stake between them.
Is an app slowing my store down?
The reviews app has added 0.6 s to product pages since it was installed on the 3rd. Checkout is not affected.
Where does mobile fall behind desktop?
Product pages. They are 1.8 s slower on mobile, and that is where most of the gap between mobile and desktop sales sits.
Inside the product
Three screens, one question answered
How much is my website costing me, and what do I fix first?
Loss
Last 28 daysAt stake
$3,140
/mo
Pages to fix
3
of 38
Mobile LCP p75
4.1 s
target 2.5 s
| Page | Problem | Fast vs slow conv. | At stake |
|---|---|---|---|
| 1/checkout | LCP 4.1 s | 41% vs 29% | $1,200/mo |
| 2/pricing | INP 480 ms | 2.6% vs 1.2% | $740/mo |
| 3/course/masterclass | CLS 0.24 | 2.1% vs 1.7% | $310/mo |
| 4/ | LCP 2.9 s | 1.9% vs 1.6% | $190/mo |
Fix #1 first: the hero image on /checkout is 1.8 MB and loads after two third-party scripts.
Then the alerts do the rest
Every signal flows into one place. When a deploy, a new app or a theme change makes things worse, you hear about it the same day, with the page and the price.
Deploy watch — A new release is compared with the week before it. If a page gets slower, you get an alert naming the page and what it now costs.
How it works
How it works for online stores
- 1
Get your revenue report
Share your store URL and a sales export. In 48 hours you know what each slow page costs you.
- 2
Add the tracker to your theme
One script tag in your theme. Under 2 KB, no cookies, no consent banner.
- 3
Connect your orders
Orders arrive by webhook and meet the speed data page by page, ranked by money at stake.
Store platforms
- ShopifyFirst integration
- WooCommerceNext
- PrestaShopOn the roadmap
- VTEXOn the roadmap
- MagentoOn the roadmap
- Any other storefrontTracker only
Using something else? Tell us, and we’ll prioritise what stores ask for.
FAQ
What store owners ask first
Talk to a person
Nothing here is a chatbot. Write to us and a founder answers, usually the same day.
Write to usDo I need to be on Shopify?
Do apps really slow a store down?
Will the tracker slow my site down?
What do you need from me for the report?
What if the report doesn’t find anything worth $99?
Is it GDPR friendly?
still guessing?
See what your slow pages cost your store, before your next sale
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