Part of the OpoShop ecosystem

Let shoppers put your products side by side.

Filters narrow a list. Sideby answers the question that comes next — which of these is right for me? — with a comparison drawer built from the specs you already wrote.

No code Installs in minutes ★★★★★ 4.9/5 from 1,400+ stores

Built for OpoShop · Trusted by stores like

Harbour & Pine Northsong Supply Velle Cosmetics Ridgeline Tools Solva Nutrition
2–5
products a shopper can weigh at once
0px
of layout shift added to your storefront
2
read-only scopes — Sideby never writes
1
click to build your sheet automatically

Why Sideby

A comparison your shoppers
can actually decide from.

Most stores answer "which one?" with a longer product description. Sideby answers it the way electronics retailers figured out decades ago: put them next to each other and let the differences do the talking.

Builds its own sheet

Sideby reads your catalogue once and finds what your products already say about themselves — the fields you wrote, the options you sell in — then proposes the rows worth comparing on. You press one button.

Marks the best value

The lowest price, the highest rating, the lightest weight — marked in your accent colour. Only ever where the values are numbers and they genuinely differ, so the mark always means something.

Hides what matches

One toggle folds away every row where the products agree, leaving only the lines a decision actually turns on. It is the difference between a spec dump and an answer.

Never moves your store

The Compare control sits below your buy box; the card pill floats inside the card's own box. Nothing is repositioned, nothing is covered, and there is no layout shift. Remove Sideby and your DOM is exactly what it was.

Always your live prices

Every cell is read from your storefront's own product data at the moment the drawer opens. Change a price or sell out a size and the comparison is right immediately — there is no copy of your catalogue to go stale.

Tells you what they can't tell apart

Sideby records which pairs of products keep ending up next to each other. That list is your merchandising problem, written down — and nothing else in your stack can produce it.

How it works

Three steps, and only one of them is yours.

Sideby does the reading. You look at what it proposes and decide whether you agree.

1

Install it

One click from the OpoShop App Store. No theme editing, no code, no snippet to paste. Nothing appears on your storefront yet.

2

It reads your catalogue

While you read the first sentence of setup, Sideby is finding the attributes your products already carry and measuring how many of them share each one.

3

You turn it on

Glance at the live preview of what a shopper will see, then press one button. Compare appears on your product pages and collection cards.

On your storefront

A tray that follows them, a sheet that answers them.

Shoppers tag products as they browse. The tray docks at the bottom of the page and comes with them from the collection grid to the product page and back. When they're ready, it opens into the sheet.

  • Compare on product pages and collection cards
  • Picks survive a page change — kept in their browser, never on our servers
  • Sticky row labels; two columns visible on a phone, all of them on a laptop
  • Sold-out, low-stock and sale prices shown honestly
  • Sits above any sticky buy bar — it can never cover Add to Cart
Your product page
Heavyweight Crew — Bone
$38.00
Size · XS–2XL  ·  Colour · 3
Add to cart
Compare
Added below the buy box — your Add to Cart button does not move.

In your admin

One column, in the order a shopper reads it.

Sideby's admin is laid out as the thing it edits. Drag a row and it moves in the live preview beside it. Rename it, decide whether the lowest or highest value gets the mark, or fill in the products that had a gap.

  • Coverage on every row — how many of your products can answer it
  • One row can absorb several spellings, so "Material" and "Fabric" land on one line
  • Type a value by hand for any product; yours always wins
  • Matches your theme's own button colour and corner radius automatically
  • Every shopper-facing word is yours to rewrite
Your compare sheet
Price100%
Availability100%
Rating72%
Fabric88%
Sizes94%
SKU100%

Loved by merchants

What changed after they installed it.

MK
Maya K.
Apparel · 240 products
★★★★★

We sell four weights of the same tee and support answered "what's the difference?" every single day. It found the fabric field we'd already written and turned it into a row. That question mostly stopped.

DR
Dan R.
Tools & hardware
★★★★★

The pairs list was the surprise. Two of our drills were being compared constantly and one was winning every time. We stopped stocking the other one.

SO
Sofia O.
Supplements
★★★★★

I was nervous about anything that touches the storefront. It genuinely doesn't move a thing — I screenshotted before and after and they were identical apart from the button.

FAQ

The things merchants ask first.

Do I have to enter specs for every product?
No — that's the point. Sideby reads your catalogue and builds the sheet out of what your products already carry: your own product fields, the option axes you sell in, and the facts every store has (price, stock, rating, delivery time). If a handful of products have a gap you care about, you can type those values in by hand, and yours always wins.
Will it change how my storefront looks?
Only by adding one control. Nothing existing is moved, restyled, hidden or wrapped. The product-page button goes below your buy box in normal flow, so your Add to Cart cannot shift. The card pill floats inside the card's own box and takes up no layout space. The tray and the sheet are fixed overlays. Screenshot your store with Sideby on and off — they should be identical apart from the intended addition.
What if it fails to load?
Your store looks and behaves exactly as if Sideby were not installed. Every network call, DOM operation and storage access is guarded, and the failure mode is always "show nothing" rather than "show something broken". It also never runs on cart or checkout pages, and never in your theme editor.
Is this the same as my store's filters?
No. Filters and sorting narrow a list down — they answer "show me fewer things". Sideby starts where that ends: the shopper already has three candidates and wants to know how they differ. Laying products alongside each other is a different job, and it is the one that closes the sale.
What data does Sideby collect about shoppers?
Counts, and nothing else. How many comparisons were opened, which products were in them, and which were clicked through to. No shopper id, no session, no IP address, no user agent, no cookies of our own. A shopper's selection lives in their own browser. There is nothing in our database that could identify a person.
What access does it ask for?
Two read-only scopes: your user record (to confirm you own the store you're opening it from) and your products (to find comparable attributes). No orders, no customers, no write access of any kind, and no webhooks. The shopper-facing half needs no access at all — it reads your products the same way your own product pages do.
Does it work on phones?
Yes, and it's designed for them first. On a phone the sheet fills the screen, the row labels stay pinned to the left, and the product columns scroll sideways — two visible at a time, which is how people actually compare on a small screen. The tray shrinks to thumbnails and a button.
How many products can be compared at once?
Two to five, and you choose the ceiling. Four is the default because it fits comfortably on a laptop and still scrolls cleanly on a phone. Past five the columns get narrow enough that a shopper is squinting instead of deciding.

Stop making shoppers hold three tabs open.

Install Sideby, glance at the sheet it builds from your own catalogue, and turn it on. The whole thing takes about as long as reading this page.

Get it on the OpoShop App Store