If the rows are different products, give each one its own URL handle. If the rows are variants of one product, put an option name on the first row (for example Size) and a different option value on each row. Rows that only add an extra image should have the handle and the image link, and nothing in the price, option or inventory columns.

Shopify import error: "Validation failed: The variant 'Default Title' already exists"

What it means: Several rows share one URL handle, but the product has no option names or values. Shopify names a variant without options "Default Title", so the second such row is a duplicate. It often happens when rows meant as separate products were given the same handle, or when variant rows were left without Option1 name and value.

Find the rows in your file

Shopify product import

Choose file

The product CSV you are about to import into Shopify, or the one Shopify just rejected.

Your file stays on this device

It is read and converted by this page, inside your browser. Nothing from the file is uploaded, and the tool keeps working offline once the page has loaded.

Loading the converter...

How to fix it

If the rows are different products, give each one its own URL handle.
If the rows are variants of one product, put an option name on the first row (for example Size) and a different option value on each row.
Rows that only add an extra image should have the handle and the image link, and nothing in the price, option or inventory columns.

Example

A file with this problem

Title,URL handle,Status,Option1 name,Option1 value,Price,Inventory tracker,Inventory quantity,Continue selling when out of stock,Fulfillm...
Cotton Tee,cotton-tee,active,,,20.00,shopify,5,deny,manual,
Linen Tee,cotton-tee,,,,24.00,shopify,5,deny,manual,

What the checker says about it

Line 2: "cotton-tee" has 2 variant rows but no option names, so the variants cannot be told apart ("options are not unique").
Line 3 repeats the handle "cotton-tee" with a different Title ("Linen Tee"). If this is a different product, give it its own handle.

Once the listed rows are fixed, check the file again; the checker also looks for every other problem Shopify documents, so you do not trade one error for the next.

Questions

What does "Validation failed: The variant 'Default Title' already exists" mean in Shopify?: Several rows share one URL handle, but the product has no option names or values. Shopify names a variant without options "Default Title", so the second such row is a duplicate. It often happens when rows meant as separate products were given the same handle, or when variant rows were left without Option1 name and value.
How do I fix it?: If the rows are different products, give each one its own URL handle. If the rows are variants of one product, put an option name on the first row (for example Size) and a different option value on each row. Rows that only add an extra image should have the handle and the image link, and nothing in the price, option or inventory columns.

Other Shopify import errors

Sources

Shopify Help Center: Solutions to common product CSV import problems: https://help.shopify.com/en/manual/products/import-export/common-import-issues

Based on Shopify's help pages for product CSV import. Not tested on a live store.