"My product CSV is too big to upload" — 15 MB file size limit

Why a plain-text CSV gets this big

A CSV has no formatting, images, or styling to bloat it — it's just text — so a file crossing 15 MB usually means a large amount of actual text data, not accidental cruft. The biggest contributor in Shopify's format specifically is that every variant row repeats the entire product record: title, vendor, product type, tags, and the full Body (HTML) description are written out again on each size/color row rather than stored once per product. A product with 20 SKU variants carries its description 20 times over.

Where the text itself piles up

Descriptions are the other major factor. Pasting formatted text from a Word document or a webpage into the Body (HTML) field often brings along a large amount of inline styling markup that a browser never shows you but that still counts as text — a paragraph that looks like a few sentences can carry several kilobytes of wrapping tags and inline styles. Multiply that by thousands of variant rows and the file grows fast.

How to get under the limit

Split the catalog into multiple smaller CSV files and upload them one after another — Shopify's product import adds or updates products by Handle, so it doesn't need your entire catalog in a single file. Separately, clean up Body (HTML) fields to strip unnecessary pasted markup down to simple text or minimal HTML; that alone can shrink a heavily-formatted file substantially without touching a single product's data.