Sizer
A size guide fewer questions and returns
Sizer lets you build reusable size charts and show them on your WooCommerce products in an accessible modal. Build a chart once, assign it to products, and the guide appears on the product page.
Works with
See it in action
Size uncertainty ends in a return
A shopper is not sure the size will fit, so they either ask before buying or buy and return. Without a clear size chart, questions and returns climb and conversion drops.
- ✗ No size chart on the product page
- ✗ Shoppers do not know which size to pick
- ✗ More pre-sale questions and more returns
- ✗ Size charts that are not keyboard or screen-reader accessible
Sizer shows a clear size guide
- ✓ Reusable size charts built once and used everywhere
- ✓ Per-product chart assignment
- ✓ An accessible native dialog modal
- ✓ No-layout-shift rendering, with reduced-motion and dark mode
What you get in the free version
Everything you need to show a size guide on the product page.
Reusable size charts
Build a labelled table of rows and columns once and reuse it everywhere.
Per-product assignment
Assign a chart to a product from the Product data → Size guide tab.
Accessible modal
A native dialog element that is keyboard operable, focus-managed and screen-reader friendly.
No external requests
Charts and settings stay in your own database, with no tracking.
Configurable button text
Set the button label and the modal heading from one settings screen.
Themeable and responsive
No-layout-shift rendering that respects reduced-motion and dark mode.
Graceful by design
Nothing renders when a product has no chart assigned.
Template overrides
Override templates from your theme under a sizer/ folder; CSS exposes custom properties.
Up and running in three steps
Create a chart and show the first guide on a product page.
Install
Activate Sizer alongside WooCommerce.
Create a chart
In WooCommerce → Size Guides, build a chart.
Assign it
Assign the chart on a product and open the product page.
Who it is for
When size is uncertain, a clear chart that cuts questions and returns.
Fashion and apparel
A clear size chart on every product page.
- ✓ Accessible modal
- ✓ Per product
- ✓ Build once
Stores with many product lines
One reusable size chart assigned across many products.
- ✓ Build once
- ✓ Per-product assignment
- ✓ Same chart everywhere
Accessibility-minded stores
An accessible dialog modal operable by keyboard and screen readers.
- ✓ Native dialog
- ✓ Focus management
- ✓ Reduced-motion
What PRO adds, and why it matters
Store-wide default chart
Fallback chart for products with no per-product or category assignment (shipped).
Per-variation charts
Show a different chart depending on the variation the shopper selects (shipped).
Unit switching
Toggle the chart between cm and inch with one control (UnitSwitch, shipped).
Find my size
Measurement form that suggests a size from the chart (FindMySize, shipped).
Import / export
JSON backup for all charts or CSV for a single chart (ChartImportExport, shipped).
What you get: FREE vs PRO
PRO keeps everything in the free plugin and adds the modules below.
Sizer vs YITH Product Size Charts vs Woo Size Chart
How Sizer compares to the popular WooCommerce size-charts plugins.
| Sizer | YITH Product Size Charts | Woo Size Chart | |
|---|---|---|---|
| Free version | Yes | Yes | No |
| Reusable size charts | Yes | Yes | Yes |
| Per-product assignment | Yes | Yes | — |
| No external requests | Yes | — | — |
| Per-variation charts | Pro | — | — |
| Find my size | Pro | — | — |
| Open source (GPLv2) | Yes | Core GPL | Core GPL |
| Paid plan price | from €29/yr | Free + premium | Paid only |
Competitor data and pricing as of June 2026; check the vendors' sites for current pricing.
Need more? Sizer PRO
FREE covers reusable charts and per-product assignment. Sizer PRO adds a fallback default chart and per-variation charts.
- ✓ Default size chart (shipped)
- ✓ Per-variation charts (shipped)
- ✓ Unit switching cm/inch (shipped)
Support and resources
Every plugin has its own documentation with setup walkthroughs. Bugs and questions go to the public GitHub repository for that plugin, we answer in the open.
Frequently asked questions
Does it require WooCommerce?
Yes. Sizer extends WooCommerce single product pages and renders nothing without WooCommerce active. WooCommerce is declared as a required plugin. The plugin itself is free and GPLv2-licensed.
Where does the size guide appear?
On the single product page, Sizer adds a “Size guide” button right after the add-to-cart button. Clicking it opens the chart in an accessible modal dialog. The button only appears on products that have a chart assigned.
Can I use one chart on many products?
Yes. You build a chart once under WooCommerce → Size Guides, then assign it on each product from the Product data → Size guide tab. The same chart can be assigned to any number of products. Assignment is done per product.
Can I override the styling?
Yes. Sizer’s templates can be overridden from your theme by placing them in a sizer/ folder. The storefront stylesheet exposes CSS custom properties (accent colour, radius, dialog colours) you can re-theme. The stylesheet also ships dark-scheme and reduced-motion variants.
Is the modal accessible?
Yes. Sizer uses a native <dialog> element with a labelled heading, a close button and keyboard support. The dialog also respects the prefers-reduced-motion setting. It is screen-reader friendly.
What happens when a product has no chart?
Nothing is rendered. Sizer only adds the button and dialog when a product has a chart assigned. On products with no assignment the page is left untouched.
Does Sizer connect to external services?
No. Sizer makes no external requests and loads no remote scripts or fonts. Charts and settings are stored in the sizer_charts and sizer_settings options, and each product’s assignment in _sizer_chart_id post meta. No data leaves your site.
Does Sizer pair with Swatch and Shortlist?
Yes. Swatch shows variations as swatches and Shortlist adds a wishlist. Sizer complements the product page with a size guide.
How does Sizer compare to YITH Product Size Charts and Woo Size Chart?
Sizer is a free, open-source size guide with reusable charts, per-product assignment, and no external requests, adding per-variation charts and a find-my-size tool in its paid edition from €29/yr. YITH Product Size Charts is freemium with a premium tier, and the official Woo Size Chart is a paid Marketplace extension. All three are distributed under the GPL. Pricing as of June 2026.
Add a size guide
Reusable charts, an accessible modal or tab, per product and per category. The full FREE edition under GPL.
Read the docsFREE is a complete size guide, PRO adds a site-wide default chart, per-variation charts and unit switching.