Size charts that help customers buy with confidence
Fitly lets Shopify merchants create professional size guides and display them on product pages — without touching code or their theme. When customers know their size before they buy, they buy with confidence and keep what they order.
The problem
For online fashion and apparel stores, the number one reason customers return clothing is wrong size — not quality, not appearance, not shipping.
- Shoppers leave product pages without buying because they're unsure which size fits.
- When they guess wrong, they return the item — costing reverse shipping, inspection, and restocking.
- Both outcomes cost merchants money: lost sales on one side, returns on the other.
How Fitly helps
Fitly removes sizing uncertainty at the moment of decision. A merchant can be set up in three guided steps, and every assigned product page gets a clear “Size Guide” button.
- Build professional size charts from templates or from scratch — no coding.
- Assign a chart to a product, collection, vendor, or tag, with inheritance so coverage scales.
- Customers open the guide, find their size, and buy with confidence.
Features
Key features
Everything Fitly does, in one focused feature set.
No-code chart builder
Build charts from flexible blocks — rich text, size tables, and measurement-diagram images — with drag-and-drop and a live preview. Start from 15+ templates or a blank chart for any vertical.
Assign by product, collection, vendor or tag
Bulk-assign one chart across hundreds of products. Charts inherit down the hierarchy, so a product without a direct chart resolves from its collection, vendor, then tag.
Built-in analytics
A dashboard tracks views, engagements, click-through rate, return-rate trend, per-chart performance, and a per-product confusion score — so the impact is measurable.
Unit conversion
Mark which columns are measurements and let shoppers toggle between cm and inches (and other length, weight, area, and volume units) right inside the guide.
Flexible display
Show a floating button, an inline button, an in-sentence text link, or a mix — with separate desktop and mobile positioning. Opens as a modal, side panel, or mobile bottom sheet.
Fast and always in sync
Charts are delivered through Shopify metafields, so the widget loads with the page — no external requests slowing the product page down — and stays in sync when charts change.
Chart builder
Build any chart, no code required
Charts are built from flexible blocks — rich text, size tables, and measurement-diagram images — arranged in any order with drag-and-drop, next to a live preview.
15+ ready-made templates
Men's and women's fashion and footwear, each shipping with a measurement diagram, guidance text, and a pre-filled size table.
Start from scratch, any vertical
Templates are a head start, not a requirement. Build a chart from a blank canvas and still get every feature.
Spreadsheet-style tables
Add, delete, duplicate, and reorder rows and columns inline; orient sizes along the first row or the first column.
Measurement-aware columns
Mark which columns are measurements so labels like “Cup” or “US / EU / UK” stay untouched by the unit toggle.
Live preview
See exactly how the chart will look to shoppers as you edit it, block by block.
Duplicate charts
Reuse a layout across product lines instead of rebuilding it each time.
Display & placement
Show the guide exactly where it fits
Choose how and where the size guide appears — floating, inline, or both at once — with separate desktop and mobile behaviour.
Floating button
A persistent button fixed to the product page, with separate desktop and mobile positions (corners or edge-centered), pixel offsets, and vertical or horizontal orientation.
Inline button
Dropped into the product template from the theme editor so it looks like a native part of the page.
In-sentence text link
A natural link woven into a sentence — e.g. “Find your perfect fit with our size guide” — with independently coloured prefix, link, and suffix text.
Clean overlays
Opens as a centered modal or a left/right side panel on desktop, and a bottom sheet on mobile.
Display rules
- Show the button only on products that have a size option.
- Show it only on products with an assigned size chart.
- Both rules are on by default, so the button never appears where it doesn't belong.
- Stores without size variants (jewelry, furniture) simply switch the size-option rule off.
Customization
Make it look like your store
A visual editor with live preview gives merchants full control over how the size guide looks — no code required (though code is available when you want it).
Button
- Custom text per placement (e.g. “Size Guide”, “Find My Size”)
- Solid, outline, or text-only style
- Button and text colors
- Font size, padding, and border radius
Icon
- Ruler, tape, measure, scale, scissors, none, or a custom upload
- Placement before text, after text, icon-only, or text-only
Popup & advanced
- Header text, position (center / side panel), corner radius, font size
- Floating position and offsets, set separately for desktop and mobile
- Custom CSS on Growth and Pro for pixel-perfect control
- Changes apply instantly across the storefront — no redeploy
A closer look
Inside the app
A preview of Fitly's interface.
Illustrated interface previews with sample data. See the live app on the Shopify App Store.
How it works
Set up in three steps
From install to insight — no heavy lifting required.
Enable the widget
One toggle in the theme editor, reached through a direct deep link from the app — no code and no theme editing.
Build a size chart
Pick a template, fill in the measurements, and preview it live. Or start from a blank chart for a non-apparel vertical.
Assign it to products
Assign by individual product, collection, vendor, or tag. From then on, every assigned product page shows a Size Guide button.
Measurable results
See the impact, don't just assume it
A built-in analytics dashboard (with date ranges from 7 days to a full year) makes the impact of your size guides measurable — not just assumed.
Returns prevented
Compares your return rate after installing against the pre-install baseline.
Revenue protected
Puts a dollar value on that reduction in returns.
Views, engagements & CTR
How often size guides are seen and opened across the store.
Return-rate trend
A before/after timeline with your install date marked.
Per-chart performance
Views, engagements, CTR, and a health rating for every chart.
Per-product confusion score
Highlights products where shoppers hesitate between sizes, with the top selected size and a size-distribution breakdown.
Reported figures are calculated by the app from your own store's data. Results vary by store, catalogue, and traffic.
Speak your customers' language
Stores selling in multiple languages can localize the entire experience per published Shopify locale.
- Widget text — button labels, the inline text-link sentence, and the popup header.
- Chart content — text blocks, table headers and cells, and image alt text, edited chart-by-chart with a language switcher.
- Measurement values are deliberately never translated, so numbers stay accurate.
- Locales fall back sensibly (for example, fr-CA falls back to fr).
Full translations are available on the Pro plan.
Who it's for
Made for the right stores
Where Fitly makes the biggest difference.
Fashion & apparel
Boutiques and DTC brands where a medium-vs-large decision makes or breaks the sale.
Footwear & sportswear
Stores where fit is technical and shoppers routinely check measurements before buying.
International stores
Sellers who need unit conversion and (on Pro) translated size guides per published locale.
Beyond apparel
Jewelry, furniture, sporting goods, and pet supplies — any store where customers need dimensions can build charts from scratch.
A good fit for
Why Fitly
How Fitly compares
What many size-chart apps stop at — and what Fitly does instead.
Pricing
Start free, upgrade when you're ready
Every plan includes the templates, customization, display rules, unit conversion, and analytics.
Free
Try & explore
3 published charts
- All 15+ chart templates
- Fully customizable charts
- All assignment & display rules
- Unit conversion
- Full analytics dashboard
Growth
Convert more
or $49.99 / yr
15 published charts
- Everything in Free
- Custom CSS for pixel-perfect styling
Pro
Maximize fit accuracy
or $149.99 / yr
Unlimited published charts
- Everything in Growth
- Full widget & chart translations per locale
- Ideal for large or international stores
Billed monthly or annually (annual saves roughly 17%). Every install starts with a free trial that unlocks all features, and billing is handled entirely through Shopify's native billing — no separate payment details. Prices shown in USD; check the App Store listing for the latest details.
Trust & compliance
Built to be dependable
The operational details that matter once it's running on your store.
Native Shopify billing
Billing runs entirely through Shopify's billing API — merchants never enter payment details separately.
GDPR compliant
Full GDPR webhook coverage: customer data request, customer redact, and shop redact.
Public policies
Privacy policy and terms of service are accessible outside the app.
In-app live chat
Support is built into the app admin, so help is a message away during setup and beyond.
FAQ
Common questions
No. Setup happens in the app admin plus a single toggle in the Shopify theme editor, reached through a direct deep link. No code and no developer required.
Ready to get started?
Install Fitly from the Shopify App Store and start with a free trial that unlocks every feature.