Best Shopify Size Chart Apps [1M-Store Study]

TL;DR

• Our October 25 analysis of Shopify size chart apps found tracked size-chart or fit-tool names on 10,646 of 1,053,913 recently scanned records (1.01%).
• Kiwi matched 9,662 records, or 90.76% of that matched group.
• Compare actual measurements, product mapping, mobile placement and recommendation requirements.

October 25 refresh: recent size-chart signals

We extracted one consistent cohort on October 25, 2026: 1,053,913 store-domain records, each with a successful full snapshot from September 25 through October 24 (UTC observation dates). We selected the latest qualifying snapshot per record, required recorded app and pixel lists, and excluded 3,048 records currently marked confirmed dead. Scans with no detected apps or pixels remain in the denominator. This is our recent scan coverage, not a representative census of live Shopify merchants.

Traffic tiers come from the same snapshots. Detector versions were not recorded in this cohort, so treat the older and newer studies as separate snapshots. The query and aggregate output record the counting rules and observation window.

We matched 17 specified size-chart and fit-tool name groups, using the aliases from the earlier research, normalized for case and surrounding spaces. The following twelve groups had matches; the other five had none in this cohort.

Provider groups can overlap on a record. These percentages use the 10,646 matched records, not all Shopify stores, so do not add them as exclusive market shares.

Only 26 records occupy the 1M–5M tier, so its 6 matches are a small sample. For an account review, inspect the actual size guide before using an app-name match to prioritize research.

The June tables below keep their original dates and denominators. This October cohort is larger and requires a recent successful scan.

Our June size-chart findings

Our June 27, 2026 extraction matched size-chart, size-guide, or fit-tool names on 8,083 of 750,598 store records with app data: 1.08%. Kiwi appeared on 7,121 records, or 88.1% of the matched group, and Fashion accounted for 7,327 records, or 90.6%.

A theme section, image, product-description table, metafield, or custom fit flow can supply sizing information without a matching app name.

Method and scope

We used stored app-name records and recorded category, traffic, theme, catalog, pixel, and contact fields. Confirmed-dead records were excluded. No maximum scan or contact-verification age was imposed. Counts below describe the June extraction.

Names and categories identify candidate app families. Vendor co-detections overlap, so percentages can exceed 100% in total.

Current vendor capabilities were checked separately on October 25, 2026 using App Store listings.

Avada is a historical name match in this table, not a current installation recommendation.

Chart-tool and fit-tool name families

The original script placed Kiwi and conventional chart-tool names in one family, and True Fit, Smartsize, Sizebay, Bold Metrics, EasySize, Virtusize, and Fit Analytics in another:

This partition follows the script's app-name rules. It is not a static-chart versus AI-feature split: Kiwi itself offers AI fit and custom size recommenders.

The 83 figure is the union of the named fit-tool family (69 plus 14), not a count of all enabled fit technology.

Match rates by estimated traffic

The higher-traffic groups had higher match rates. The traffic query's total was 750,598; a separately run no-app comparison returned one additional record, so the two outputs are kept separate.

For context, 6,255 matched records were in 50K+ tiers and 7,011 had five or more detected apps. These attributes help allocate account-review effort.

Current tools to evaluate

Start with the measurements and maintenance workflow your products require. A simple theme-native table can be sufficient when it is accurate, accessible, and maintained. An app helps with reusable rules, collection mapping, unit conversion, or a validated recommendation requirement.

Kiwi's October 25 USD monthly pricing listed Free for up to three published charts, Premium $7.99 for up to ten charts, Plus $14.99 for up to twenty charts and ten custom recommenders, and Ultimate $26.99 for unlimited charts/recommenders. Plus and Ultimate disclose additional order-volume charges; import credits can be extra. A low headline subscription price is therefore not the whole cost. Recheck the chosen plan before subscribing.

The listings show advertised capabilities. Test them, and any effect on returns, with your own product and order data.

A concrete sizing inspection

On October 10, our public review of a Gymshark product page found seven listed sizes, XXS through XXL, and a size-guide control.

That is already enough to prevent the claim "no detected chart app means no size guidance." A follow-up review should inspect the guide's measurements, units, product specificity, and mobile accessibility, then use authorized support or returns evidence to determine whether sizing is a problem.

Candidate pools for inspection

The June rules found 104,431 records in fit-sensitive categories with 50K+ estimated traffic, no tracked size/fit-family match, and at least one stored contact. The fashion-only cut contained 56,242.

"Contact" means any stored contact row, which can be a social profile or generic address, so treat these totals as account-research candidates.

Before an account-specific pitch:

1. Inspect theme-native, image, description, and custom sizing information.
2. Check product measurements, units, measuring instructions, and garment-specific exceptions.
3. Test mobile placement and accessibility.
4. Confirm sizing questions, return reasons, and the merchant's objective using authorized evidence.
5. Identify and verify the current person responsible for product content or merchandising.
6. Apply current email verification and campaign exclusions separately.

Use the T-shirt store examples for manual product-page research and the contact enrichment workflow for the contact layer.

FAQ

Is Kiwi the best size-chart app?

It is the most detected: it had the largest matched footprint in both our June study and October refresh, and it currently advertises both chart and recommendation features. Choose using your measurement, rule, localization, and maintenance requirements, then test the relevant feature on your products.

Does 1.08% mean most Shopify stores have no size guides?

No. It is the matched app-family rate in the historical app-record dataset. Native theme sections, images, custom code, and other implementations can supply guides without those names.

How common are AI fit recommendations?

Named fit-tool apps are rare: the June query's fit-tool family matched 83 records. Kiwi and other chart-family tools also offer recommendations, and that count does not include them.

Should a merchant choose a chart or a recommender?

Start with clear, maintained product measurements. Consider a recommender when a documented requirement needs additional logic and the required product data is available. Confirm accuracy and economic outcomes before replacing an adequate native or app-based guide.