Turn product attributes like brand, category, model, size and color into short, consistent SKU codes. Set the segment order, code length and separator once, generate every size and color variant at once or paste a CSV product list, and download the result as a spreadsheet.
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Every size × color combination becomes one SKU. Leave a list empty to skip that attribute.
Recognized columns: brand, category, product (or name/model), extra (or material/style), size, color (or colour). Other columns are kept in the export. You can also .
Example SKU–
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How to use the SKU Generator
Enter the product attributes: brand, category, product name and the lists of sizes and colors (or switch to Bulk from CSV).
Arrange the segments in the SKU rules: tick the parts you want and move them left or right.
Pick the code length, style and separator, and add custom codes such as Forest Green = FGR.
Click Generate SKUs; the table also updates as you type.
Download the CSV or copy the SKUs into your inventory, store or spreadsheet.
Anatomy of a well-structured SKU
A SKU reads from general to specific. With the default rules, a medium black organic-cotton T-shirt from the Northwind brand's Classic Crew line can look like this:
Segment
Value
Code
Why
Brand
Northwind
NRT
Separates product lines if you sell several brands
Category
T-Shirt
TSH
Groups similar items when sorting
Product / model
Classic Crew
CCR
Identifies the design
Size
Medium
M
Standard size code
Color
Black
BLK
Standard 3-letter color code
Result: NRT-TSH-CCR-M-BLK. Turn on the Extra segment to include material (OC for organic cotton), or add a sequence number for items without distinguishing attributes.
Common size and color codes
Size
Code
Color
Code
Color
Code
Extra small
XS
Black
BLK
Gray / Grey
GRY
Small
S
White
WHT
Brown
BRN
Medium
M
Navy
NVY
Beige
BGE
Large
L
Blue
BLU
Charcoal
CHR
X-Large
XL
Green
GRN
Olive
OLV
XX-Large
XXL
Red
RED
Natural
NAT
One size
OS
Yellow
YLW
Multicolor
MLT
SKU best practices
Decide the format once. Changing SKUs later breaks reports, reorder history and marketplace listings.
Keep codes fixed-length per segment so SKUs sort neatly and are easy to read on a shelf label.
Use only letters, digits and one separator. Spaces, slashes and symbols cause trouble in URLs, barcodes and spreadsheets.
Don't encode things that change such as price, supplier or warehouse location.
Never recycle a SKU. When a product is discontinued, retire its SKU rather than giving it to a new item.
Print it as a barcode if you scan stock: a Code 128 barcode can hold any SKU made of letters, numbers and dashes.
Frequently asked questions
What is a SKU?
A SKU (stock keeping unit) is an internal code a business assigns to each distinct product variant it stocks, for example NOR-TSH-CCR-M-BLK for a medium black T-shirt. Unlike a UPC or EAN barcode number, you create SKUs yourself, so they can be readable and follow your own rules.
How do I create a good SKU format?
Start with the broadest attribute and end with the most specific, such as brand, category, model, size, color. Keep every SKU short (8 to 12 characters is common, rarely over 20), use the same code length and separator everywhere, use letters and numbers only, and never reuse a SKU for a different product.
Should a SKU start with a zero or contain O and I?
It is best to avoid starting with 0, because spreadsheets may strip leading zeros, and to avoid the letters O and I, which are easily confused with 0 and 1. The 'Avoid look-alike letters' option removes O and I from generated codes.
What is the difference between a SKU and a UPC?
A UPC (or EAN/GTIN) is a globally unique number bought from GS1 and printed as a barcode so any retailer can scan it. A SKU is internal to your business and can follow any format you like. Many sellers have both for each variant.
How does the tool abbreviate words?
Smart style takes the first letter and then the consonants, so Northwind becomes NRT and Charcoal becomes CHR. Multi-word values use initials plus letters of the last word, so Classic Crew becomes CCR. Standard sizes and colors use common codes like XL and BLK, and you can override any value with a custom code.
What happens if two products get the same SKU?
The tool detects duplicates and adds a numeric suffix (for example -2) so every SKU stays unique, highlights those rows in red and reports how many were fixed. It is usually better to then add a custom code or another segment so the SKUs are meaningful.
Can I import my product list?
Yes. In Bulk from CSV, paste or load a CSV with a header row. Columns named brand, category, product (or name/model), extra (or material/style), size and color are used to build the SKU; any other columns are kept and included in the downloaded CSV.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.