SKU CSV checker

Catch duplicate identifiers, missing SKUs and small differences that are easy to miss. Your original values — including leading zeros — stay intact.

Runs in your browser
No signup or file uploads

Check your SKU list

01 / FILE REVIEW

Product CSV

Drop your CSV here

UTF-8 CSV or TSV · up to 10 MB · 20,000 records

Files are processed in this browser. No records are merged or edited. This tool checks SKU data quality; it does not validate a complete Shopify import.

Choose a CSV, paste your data or try an example to begin.

How to use this tool

Choose a UTF-8 CSV or TSV, paste a file, or try an example.
Select the column that contains your SKU. Choose whether case and outer whitespace should also be checked for potential collisions.
Run the check, review the original values and record numbers, then download the issue report.

A worked example

00123 and 123 are different SKUs. Two rows with 00123 produce an exact-duplicate warning; the output keeps both records so you can decide whether they belong together. Download the example CSV.

Know the limits

This is a general SKU preflight check, not a complete Shopify import validator or live inventory check.
Exact duplicates can be intentional. We flag them for review and never automatically delete or rewrite rows.
Record numbers count logical CSV records, including the header. A quoted multiline field can span more than one text line.
Inputs are limited to 10 MB, 20,000 non-empty data records and 150 columns. Spreadsheet reports guard common formula prefixes.

A few useful answers

Will 00123 become 123?

No. Identifiers are read as text. The checker can flag leading zeros because spreadsheet software may alter them when you open a CSV; your original input is not changed.

Are ABC-1 and abc-1 duplicates?

Exact matching treats them as different identifiers. Enable the case comparison to report them as a potential collision, then decide which meaning is correct for your business.

What happens to whitespace?

We show suspicious outer whitespace and invisible characters. The optional comparison finds likely collisions without changing the original values.

Are my product files uploaded?

No. This version processes file contents in your browser and generates downloads locally. Normal page assets still load from the website.