Seller utilities · Free tool
SKU generator
Build a numbering system that actually tells you something: brand prefix, category, sourcing date, and a clean sequence. Generate up to 500 at once, export CSV, and turn the whole list into printable barcodes in one click.
By Cluzy editors · Verified August 30, 2026
Build your SKU pattern
Toggle the pieces you want. Every setting updates the example live.
Live example
…
Your SKU list appears here
Everything runs in your browser — your inventory scheme stays yours. Pairs with the barcode generator for printable labels.
Anatomy of a SKU that works
A good SKU answers three questions before you ever open a spreadsheet: whose is it, what is it, and when did you get it. Take THR-CLO-2608-0001:
| THR | Prefix | Your brand — separates your codes from any supplier codes on the same shelf |
| CLO | Category | What it is, at a glance — clothing here; SHO, VIN, JWL, ELE for the rest |
| 2608 | Sourcing date | August 2026 — instantly see how long anything has sat unsold |
| 0001 | Sequence | The unique part — four digits carries you to 9,999 items per pattern |
The sourcing-date segment is the quiet hero for resellers: sort your unsold inventory by SKU and your oldest, staleness — the death pile — surfaces itself.
Rules that save you a year from now
- Never reuseA sold item's SKU stays retired. Reuse it and every past report about that code becomes a lie.
- No lookalikesO vs 0 and I vs 1 vs l ruin hand-typed searches. The random segment here excludes them by design.
- Don't encode the priceBuyers at in-person sales can crack a readable cost code. If you must track cost, keep it in the spreadsheet, not on the tag.
- Stay consistentOne pattern, applied always — a half-migrated scheme is worse than a bad one. Batch generation exists so day one and day 400 look identical.
- Put it everywhereeBay's Custom label field, the bag or bin label, your spreadsheet. The code only pays off when every system speaks it.
SKU FAQ
What is a SKU, exactly?
A stock keeping unit — a code you invent to identify one specific item (or variant) in your own inventory. Unlike a UPC, nobody assigns it and no registration exists: it means whatever your system says it means, which is exactly why a consistent pattern matters.
What's the difference between a SKU and a UPC?
A UPC is a global, GS1-assigned product number — the same jar of peanut butter has the same UPC in every store. A SKU is yours alone: two resellers can use THR-CLO-0001 for completely different items and nothing breaks. Use SKUs for your inventory, UPCs only when a marketplace demands a registered product identifier.
How long should a SKU be?
Eight to sixteen characters is the sweet spot. Long enough to encode prefix, category, and a sequence; short enough to read aloud, type into a search box, and fit on a small label. Every segment should earn its place.
Letters or numbers?
Both — letters for meaning (CLO = clothing), numbers for uniqueness (0042). Avoid the ambiguous characters O, 0, I, 1, and L in any hand-written or read-aloud part; this generator's random segment excludes them automatically.
One SKU per item, or per size?
Per sellable variant. If you'd list a medium and a large separately, they need separate SKUs. For one-of-a-kind thrift finds this is easy — every item is its own SKU.
Can I change an item's SKU later?
Avoid it — a SKU is only useful because it never changes. If you must migrate to a new scheme, generate fresh codes for new inventory and let old codes retire as items sell, rather than relabeling a whole death pile.
Where do I put the SKU on eBay?
The "Custom label (SKU)" field on every listing — it's private, searchable, and shows up in your sold reports, which makes matching sales to storage bins painless. Print the same code as a barcode label for the bin or bag with our barcode generator.
Is this free? Is my scheme private?
Free, no signup, no limits that matter (500 per batch, run it as often as you like). Generation happens in your browser — your inventory scheme is never uploaded anywhere.
More free tools
See all free toolsFlip your inventory faster
Scan your inventory at the rack. List it to eBay before you leave.
Cluzy identifies your inventory, pulls real sold prices on eBay, Poshmark, and Depop, and posts an optimized eBay listing in one tap. No app-switching.
Free to download · iOS & AndroidSources
Verified August 30, 2026. SKUs are your private codes — no registration exists or is needed. Generation runs entirely in your browser.