Duplicate SKU Finder
Find duplicate SKUs in your catalog in seconds. Free in-browser tool that flags exact, normalized, and near-duplicate SKUs with no upload or login.
Paste a column of SKUs or upload a CSV to find duplicate SKUs instantly — exact repeats, plus near-duplicates that hide behind inconsistent casing, padding, and punctuation. It runs entirely in your browser, so nothing leaves your machine.
Duplicate SKU Finder
Runs in your browser · no uploadThe tool flags duplicates; it never merges or deletes. Decide which record is canonical before you merge. See how Claro deduplicates catalogs with reversible merges →
What it checks
The Duplicate SKU Finder groups your identifiers and surfaces every collision it can detect, with a plain-language reason for each:
- Exact duplicates — identical SKU strings repeated across rows, the simplest and most common case.
- Normalized duplicates — values that are the same once you strip leading/trailing whitespace, collapse case, and remove separators like hyphens, dots, slashes, and spaces (for example
ABC-1024,abc1024, andABC 1024). - Zero-padding collisions — numeric SKUs that differ only by leading zeros, such as
004500vs4500, which Excel and ERP exports routinely mangle. - Whitespace and hidden-character issues — trailing spaces, tabs, and non-breaking spaces that make two “identical” SKUs sort apart in a spreadsheet.
- Near-duplicates — SKUs one keystroke apart (transposed digits, a dropped or extra character) and, when you map a title or MPN column, different SKUs that share an MPN or carry near-identical titles. These often signal a fat-fingered re-key rather than a genuinely distinct part.
- Duplicate counts and row references — how many times each value appears and where, so you can jump straight to the conflicting rows.
How it works
There is no official standard for SKU formatting — unlike a GTIN, a SKU is an internal identifier each company defines for itself. That freedom is exactly why duplicates accumulate: a furniture retailer might key the same chair as OAK-DESK-01 and oakdesk1, an MRO distributor might import GLOVE-L from one supplier and GLOVE_L from another, and a CPG team migrating between systems can double-load a row when an export is re-run.
To find duplicate SKUs reliably, the tool applies the same logic a deduplication pipeline uses, in two passes:
- 1Normalize
Each SKU is trimmed, lowercased, and stripped of common separators and hidden characters to produce a comparison key. Identical keys are grouped as exact-or-normalized duplicates.
- 2Compare for near-matches
Remaining values are compared for near-misses so transpositions and dropped characters surface as likely-but-not-certain duplicates for you to review, rather than being silently merged. A single changed character is how sequential SKUs differ (
SKU-10001vsSKU-10002), so those pairs are not flagged on the SKU alone; they show up as similar titles when you map a title column and the titles agree.
This is a fast, honest first pass. It is intentionally conservative: it flags candidates and explains why, but it will not auto-merge records. Deciding which of two duplicates is canonical — and merging them reversibly without losing pricing, supplier, or transaction history — is the harder problem that a canonical product record and a real entity-resolution layer are built to solve. Claro’s deduplication and identity-resolution platform does this across millions of records with full provenance and write-back, so a flagged duplicate becomes a tracked, reversible merge instead of a one-off spreadsheet edit.
Related resources
Playbook
How to Deduplicate a Product Catalog
A step-by-step process for finding, reviewing, and merging duplicate products at scale.
Guide
How Duplicate SKUs Corrupt Pricing and Analytics
Why a single duplicate SKU distorts inventory counts, margins, and reporting.
Glossary
What Is Entity Resolution?
The discipline of deciding when two records describe the same real-world product.
Glossary
SKU vs MPN vs GTIN
Which identifier means what — and why only some of them are safe to dedupe on.
Tool
Product Record Diff
Compare two product records attribute by attribute before you decide which to keep.
Tool
MPN Normalizer
Normalize manufacturer part numbers so designations match across suppliers.
Tool
Catalog Overlap Analyzer
Compare two catalogs to see shared, unique, and near-match SKUs.
FAQ
How do I find duplicate SKUs in Excel?
You can use Excel’s Conditional Formatting → Highlight Duplicate Values or a COUNTIF formula, but both only catch exact string matches. They miss case differences, leading zeros, trailing spaces, and separators — so ABC-100 and abc100 look distinct. This tool normalizes those variations first, then also flags near-duplicates, which a spreadsheet cannot do.
Why do duplicate SKUs happen in the first place?
Most duplicates come from data entering a catalog through more than one path: two suppliers using different formatting for the same part, a re-run export that double-loads rows, a manual re-key with a typo, or a migration between two systems that each had their own conventions. Because a SKU has no governing standard, nothing stops the same product from being represented two different ways.
Is it safe to just delete one of every duplicate pair?
No. The two records may carry different and still-needed data — one might hold the correct supplier and the other the active pricing or order history. Blindly deleting can break references in your ERP or analytics. The safe approach is a reversible merge into a single canonical record that preserves the history of both, which is why this tool flags rather than deletes.
Can two products legitimately share the same SKU?
Generally no — a SKU is meant to be unique within your own system. If you see the same SKU on two genuinely different items, that is itself a data-quality defect to fix, not a real coincidence. The exception is when you are comparing SKUs across different companies, where unrelated firms can reuse the same string by chance.
What is the difference between a duplicate SKU and a near-duplicate?
A duplicate SKU is the same identifier appearing more than once (exactly, or after normalization). A near-duplicate is two different SKUs that are suspiciously similar — a transposed digit or a dropped character — which usually means a typo created a phantom product. The tool reports both but keeps them separate so you can confirm near-matches before acting.
Claro
See where your catalog breaks — free
Claro runs this automatically: resolve identity, fill missing attributes, validate updates, and write clean records back into your PIM/ERP. Upload a sample supplier file for a free catalog audit.
Get a free catalog audit