Size and fit are the single biggest reason apparel comes back. Industry estimates put fit-related returns at roughly half of all clothing returns, and McKinsey has put the figure as high as 70% of fashion returns. Yet the size chart — the one asset that directly answers "will this fit me?" — is usually the last thing a seller makes, exported at 800px from a spreadsheet screenshot, and uploaded to every channel unchanged.
It also stopped being optional. Shopee made size charts mandatory for a long list of Apparel and Footwear sub-categories from 23 June 2025: try to create or edit a listing in one of those sub-categories without a size chart and you cannot save it. Lazada throws "Product size chart is required" errors on the same category families. Amazon requires size information for most clothing product types too.
This guide covers the specs, the format decision (image or table), and how to build one master chart that survives every channel.
Marketplace size chart specifications
Size charts are handled in two different ways depending on the platform. Some marketplaces want a data template — you fill in measurements in a spreadsheet and the platform renders the chart itself. Others want an image that you upload like any other product photo. Several accept both, and the requirements differ.
| Platform | Format accepted | Image dimensions | Max file size |
|---|---|---|---|
| Shopee | Image upload (mandatory in listed apparel/footwear sub-categories) | Minimum 500 x 500 px; upload at 1,024 x 1,024 px or higher | 2 MB |
| Lazada | Image upload | Minimum 330 x 330 px, up to 5,000 x 5,000 px | 2 MB |
| Amazon | Excel size chart template (Catalog > Add size charts) plus optional PT-slot image | Gallery images 1,000 x 1,000 px minimum for zoom; 2,000 x 2,000 px recommended | 10 MB |
| Shopify | Your choice: HTML table, app, or image | Export at 1,200 px wide minimum for mobile legibility | 20 MB (practical target: under 200 KB) |
| Qoo10 / Carousell | Image, usually as a gallery slide | Match your gallery size (1,000 x 1,000 px or larger) | Varies; keep under 2 MB |
The Amazon distinction worth understanding
On Amazon, the native size chart is a data feed, not a picture. You go to Catalog, select "Add size charts", search your ASIN, download the template for that product type, fill in the measurement columns, and upload. Amazon renders it as the "Size Chart" link next to the variation selector. That version is searchable, translatable and works with screen readers — it is the one that actually gets read.
A size chart image in a PT slot (PT01, PT02 and so on) is a supplement, not a replacement. It is still worth adding, because most shoppers never click the size chart link but do swipe the gallery. Treat the second or third gallery slot as your fit-information slide.
Image or HTML table? Pick per channel, not per brand
On marketplaces you rarely get a choice — you upload what they ask for. On your own store you do, and the answer is not the same for everyone.
When an image wins
- You need one asset that works across Shopee, Lazada, Qoo10 and your own store without rebuilding it five times.
- Your chart includes a measurement diagram — where to put the tape for chest, waist, inseam, sleeve. Diagrams beat prose, and prose is what an HTML table forces you into.
- Your theme's table styling is unreliable inside a modal, which is common on older Shopify themes.
When a table wins
- Accessibility. A screen reader can read a real table cell by cell. It cannot read text baked into a JPEG, and accessibility compliance is a legal requirement in a growing number of markets. If you use an image on your own site, the alt text has to carry the actual numbers, not "size chart".
- Search. Text in a table is indexable; text in an image is not.
- Updates. Changing one measurement in a table is a two-second edit. Changing it in an image means re-exporting and re-uploading to every channel.
The pragmatic setup for most multi-channel sellers: an HTML table (or a size chart app) on your own store, and one well-built master image for the marketplaces that demand a file.
How to build a size chart image that is actually readable
Most size chart images fail for one reason: they were designed on a 27-inch monitor and viewed on a 6-inch phone. Marketplace traffic in Southeast Asia is overwhelmingly mobile, and a chart that renders at 340 px wide on a phone has to survive that.
Canvas and layout
- Build at 1,200 x 1,200 px minimum, export at 1,024 x 1,024 px or larger. Square is the safest single shape — it fits Shopee's 1:1 gallery, Lazada's 1:1 requirement, and Amazon's square gallery frame without cropping.
- Cap the columns at six. Size, chest, waist, length, shoulder, sleeve. Anything more and the text has to shrink below readable size. If you need more measurements, split into two slides.
- Cap the rows at eight to ten sizes. Longer size runs need a taller canvas — go to 1,200 x 1,600 px and accept it will be a separate export for the 1:1 channels.
Type and contrast
- Minimum 28 px type on a 1,200 px canvas. That is roughly 2.3% of the canvas height, which stays legible when the image scales to phone width. Test it: shrink your export to 400 px wide and read it at arm's length.
- Pure black text on white, or near-black on very light grey. Avoid mid-grey on white — it looks refined in the design tool and disappears on a phone in daylight.
- Alternate row shading at about 4% grey. It costs almost nothing in file size and dramatically reduces mis-reads across a wide row.
- One font, two weights. Bold for the header row and the size column, regular for everything else.
Content that prevents the return
- State the unit twice — in the header ("Chest (cm)") and in a footnote. Cross-border buyers assume the wrong unit constantly. If you sell to both metric and imperial markets, show both, or export two unit variants.
- Say whether measurements are garment or body. "Garment laid flat" and "body measurement" produce numbers that can differ by 8 cm on the same item. This single omission drives an enormous share of fit returns.
- Add a tolerance note — "measurements may vary by 1-2 cm due to manual measurement" is standard and heads off disputes.
- Include a "model is wearing" line if you use on-model photography. Height, usual size, and the size worn in the photos. It is the cheapest fit-confidence signal you can add.
File format and compression
A size chart is flat colour and sharp text — the exact content type where JPEG performs worst. JPEG compression smears the edges of small numerals, which is how a chart that looked fine on export becomes an unreadable "8 or 3?" on a phone.
| Format | Use for size charts? | Why |
|---|---|---|
| PNG-24 | Best quality | Lossless, crisp text edges; typically 150-400 KB at 1,200 px for a simple chart |
| PNG-8 | Best size and quality balance | A chart uses few colours; 8-bit often lands under 100 KB with no visible loss |
| JPEG | Only if required | Acceptable at quality 90 or above; below that, numerals degrade. Amazon prefers JPEG for gallery images |
| WebP | Own store only | Excellent for text graphics, but inconsistently accepted by marketplace uploaders |
Where a marketplace only accepts JPEG, export at quality 92 and check the smallest numerals at 100% before uploading. If you are pushing the same master chart to Shopee at 1,024 x 1,024 px, Lazada at 1:1, and your Shopify store at 1,200 px wide, a batch tool such as PixelPrep will handle the resizing and format conversion for the whole set in one pass rather than five manual exports per product line.
Keeping charts consistent across a catalogue
The failure mode at scale is not one bad chart — it is forty charts built by three people over two years, in four fonts, with inconsistent measurement definitions. Fix it with structure:
- One template file per product family (tops, bottoms, footwear, outerwear). Duplicate and change the numbers only; never rebuild the layout.
- Name the exports predictably —
sizechart_tops_unisex_cm_1024.png. When Shopee changes a requirement you need to find and replace every affected file without opening them. - Version the source. Keep the editable file next to the export. The chart you cannot edit is the chart you will eventually rebuild from scratch.
- Re-measure when you change supplier. A "same" garment from a new factory is routinely 1-3 cm different. Reusing the old chart guarantees a return spike you will end up blaming on marketing.
Your size chart checklist
- Built at 1,200 px or larger on the short side; exported square for marketplaces
- Shopee: 1,024 x 1,024 px or higher, under 2 MB, uploaded to every mandated apparel and footwear sub-category
- Lazada: at least 330 x 330 px, under 2 MB — but match your Shopee export rather than going minimum
- Amazon: fill in the Excel size chart template first, then add an image to PT01 or PT02 as a gallery slide
- Six columns maximum, eight to ten rows maximum, larger canvas if you need more
- Type no smaller than 28 px at 1,200 px canvas; verified legible at 400 px wide
- Units stated in the header and repeated in a footnote
- Garment-flat versus body measurement stated explicitly
- Tolerance note included
- PNG where allowed; JPEG at quality 92 or higher where it is not
- Real alt text carrying the key measurements on your own site, not "size chart"
- Editable source file kept and named to match the export
A size chart will not rescue a listing with weak photography — it works as confirmation for a shopper who already believes the product is right for them. But it is the cheapest fit tool you own, it is now mandatory on the largest marketplaces in the region, and getting it wrong is one of the few image mistakes that costs you money twice: once on the return shipping, and again on the review.