The 10 Best Shopify Size Chart Apps in 2026 (Ranked & Tested)

Kiwi Sizing is the market leader for standard Shopify sizing apps. It covers three things: size chart display, a fit quiz, and — on higher plans — AI-powered size recommendations trained on your order and return data.

The size chart builder is solid. Charts sync to product variants, handle international size conversions (US, UK, EU, AU, JP) automatically, and can be configured per product category. The fit quiz asks for height, weight, and fit preference, and outputs a size recommendation. At higher tiers, the recommendation learns from your historical data and gets more accurate over time.

Size Matters does one thing: it builds size charts and puts them on product pages. No fit quiz, no AI, no measurement collection. Clean interface, minimal configuration, works in under 30 minutes.

If you have straightforward sizing, a small catalog, and you just want a guide visible on each product page without buying a platform, this is the right call. Cheaper than Kiwi. Faster than everything.

Octane AI's Fit Quiz is part of a larger conversational commerce platform. The quiz is highly configurable — every question, branching logic, and recommendation output is under your control. It works well for brands that want sizing tied into a broader product recommendation flow, not just a standalone widget.

Unlike simpler fit quizzes, Octane AI factors in lifestyle and style profile alongside body measurements. The output can be a size recommendation, a product recommendation, or both in sequence. For brands where personalisation drives serious conversion uplift, this is the most flexible option available on Shopify.

Sizebay started in Brazil and has expanded globally. Its specific strength is international size conversion — it handles US, UK, EU, BR, AU, IT, FR simultaneously, and it does this more cleanly than most apps that treat international conversion as an afterthought.

For brands selling across multiple regions — a European label shipping to North America and Australia, for instance — Sizebay reduces the size-conversion friction that drives international returns. It also runs a fit quiz and includes a virtual fitting room feature for some categories.

Modelier takes a different approach. Instead of asking customers to interpret a measurement chart, it shows them what the garment looks like on a virtual model matched to their body type. Put in your height and build, see the shirt on someone who looks like you.

For fashion-forward brands where the visual fit experience is part of the brand identity, this reduces purchase uncertainty in a way that numbers can't. A customer who can see how the cut falls on their frame is less likely to return it because it "looked different online."

Tolstoy is a shoppable video platform. Where it applies to sizing: brands use it to embed short-form video on product pages showing how a garment fits, how to measure, and how the fabric moves on a real person.

It doesn't build size charts. What it does is eliminate the "I can't tell how this fits from photos" problem — which drives a lot of returns that a size chart alone won't fix. A 60-second video of someone measuring their chest and matching it to the chart outperforms a static image of the same information. Most stores know this and don't do it anyway, usually because the video production feels like a separate project.

Smart Size Chart is worth mentioning specifically for stores with large catalogs. You can assign one size chart to an entire collection rather than configuring each product individually. For stores managing hundreds of SKUs, that matters — per-product configuration at scale is a real time cost.

It handles the basics: chart display, popup or inline layout, inch/cm toggle, basic international conversions. It won't win on fit analytics or AI recommendation. It also won't eat your afternoon setting up.

Bonjour combines size conversion and localisation, which is a smarter pairing than it might sound. European stores typically need both — the right size standards and the right language — and most tools treat these as separate installs.

For brands based in France, Germany, Italy, or Spain, or brands with significant European customer bases, Bonjour handles EU sizing conventions and multilingual Shopify setups together. It's not the most globally comprehensive tool, but it's the cleanest for the European use case.

Shopify's own size guide block is available in all Online Store 2.0 themes (Dawn, Sense, Craft, and most commercial themes). You add it to your product template in Theme Customizer, drop in a table or image, and it shows as a link that opens a popup on the product page.

It does nothing sophisticated. No quiz, no AI, no measurement capture. But it takes 10 minutes to set up, costs nothing, and works without introducing a third-party dependency.

If you're early stage, testing a product, or running a store where sizing is genuinely simple, start here. When you outgrow it, you'll know exactly what you need next.