GTIN Lookup API: How to Search Products by Global Trade Item Number

GTIN (Global Trade Item Number) is the universal standard for product identification, managed by GS1. If you're building any e-commerce application that deals with product data, understanding GTIN lookup is essential.

What Is a GTIN?

A GTIN is a globally unique identifier for a trade item (product). It's an umbrella term that covers several barcode formats:

GTIN Format	Digits	Common Name	Usage
GTIN-8	8	EAN-8	Small packages
GTIN-12	12	UPC-A	North America
GTIN-13	13	EAN-13	International
GTIN-14	14	ITF-14	Case/carton level

Key Insight

Every UPC is a GTIN-12. Every EAN is a GTIN-13. GTIN is simply the standardized framework that unifies all barcode types under one system.

Why GTIN Lookup Matters

For Amazon Sellers Amazon requires a GTIN (UPC or EAN) to create new product listings. Without a valid GTIN, you can't list products unless you have a Brand Registry exemption.

For Developers E-commerce APIs, Google Shopping, Facebook Commerce, and most marketplace integrations use GTIN as the canonical product identifier.

For Supply Chain GTIN is the foundation of the GS1 system used by retailers, manufacturers, and distributors worldwide for tracking products from factory to shelf.

How to Look Up Products by GTIN

Using EcomSource GTIN Lookup API

# Look up by GTIN-12 (UPC)
curl -X POST "https://api.ecomsource.ai/api/v1/search/product" \
  -H "X-Access-Key: your_access_key" \
  -H "X-Secret-Key: your_secret_key" \
  -H "Content-Type: application/json" \

# Look up by GTIN-13 (EAN) curl -X POST "https://api.ecomsource.ai/api/v1/search/product" \ -H "X-Access-Key: your_access_key" \ -H "X-Secret-Key: your_secret_key" \ -H "Content-Type: application/json" \ -d '{"identifier": "0012345678901", "identifierType": "ean"}' ```

The API automatically detects the GTIN format and returns the complete product record including all associated identifiers.

Response Example

{
  "gtin": "0012345678901",
  "gtin_type": "GTIN-13",
  "upc": "012345678901",
  "ean": "0012345678901",
  "asin": "B08N5WRWNW",
  "title": "Product Name",
  "brand": "Brand Name",
  "category": "Electronics",
  "images": ["https://..."],
  "weight": "0.5 lbs",
  "dimensions": "6 x 4 x 2 inches"
}

GTIN Validation

Before looking up a GTIN, validate the check digit:

def validate_gtin(gtin: str) -> bool:
    """Validate a GTIN check digit."""
    digits = [int(d) for d in gtin]
    check = digits[-1]
    total = sum(
        d * (3 if i % 2 else 1)
        for i, d in enumerate(digits[:-1])
    )
    expected = (10 - (total % 10)) % 10

# Examples print(validate_gtin("012345678905")) # True (valid UPC) print(validate_gtin("012345678900")) # False (invalid) ```

GTIN vs Other Identifiers

GTIN vs UPC: UPC is a GTIN-12. They're the same thing.
GTIN vs EAN: EAN is a GTIN-13. They're the same thing.
GTIN vs ASIN: ASIN is Amazon-specific. One product can have both a GTIN and multiple ASINs (different marketplaces).
GTIN vs SKU: SKU is retailer-specific. GTINs are universal.

Best GTIN Lookup APIs

1EcomSource.ai — 1.6B+ products, all GTIN formats, sub-200ms, free tier available
2GS1 GTIN Registry — Official but limited API access and expensive
3Open Food Facts — Free but food products only
4Barcode Lookup — Good coverage but expensive at scale

Get Started with Free GTIN Lookups

EcomSource provides 100 free GTIN lookups per day with full product data.

Start Free GTIN Lookups →/signup

---

Queries already finding EcomSource on Google (Search Console)

These are real searches where ecomsource.ai already earns impressions — prioritize the same topics in your tooling and content:

asin to upc api — 139 impressions
b2b data api — 121 impressions
b2b api — 52 impressions
gtin vs upc — 43 impressions
upc vs ean vs gtin for selling products online differences how to choose — 11 impressions
upc code — 36 impressions
product data api — 36 impressions
b2b apis — 31 impressions
amazon api search for products — 4 impressions
difference between gtin and ean gtin-13 ean-13 — 1 impressions

Related searches: UPC, barcode & product identifier keywords

This section expands on GTIN Lookup API: How to Search Products by Global Trade Item Number with search terms sellers and developers use — including queries from Google Search Console and our keyword research. Whether you need asin to upc api, product data api, gtin vs upc, b2b data api, or bulk barcode lookup, the workflows below connect to EcomSource tools.

Upc lookup

Upc lookup is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use upc lookup to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run upc lookup free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Upc code lookup

Upc code lookup is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use upc code lookup to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run upc code lookup free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Upc code

Upc code is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use upc code to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run upc code free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Barcode lookup

Barcode lookup is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use barcode lookup to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run barcode lookup free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Search for upc

Search for upc is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use search for upc to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run search for upc free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Upc code search

Upc code search is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use upc code search to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run upc code search free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Upc codes

Upc codes is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use upc codes to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run upc codes free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Sku lookup

Sku lookup is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use sku lookup to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run sku lookup free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Upc number lookup

Upc number lookup is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use upc number lookup to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run upc number lookup free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Gtin lookup

Gtin lookup is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use gtin lookup to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run gtin lookup free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Barcode number search online

Barcode number search online is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use barcode number search online to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run barcode number search online free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Sku number lookup

Sku number lookup is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use sku number lookup to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run sku number lookup free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products.

Terminology & search intent reference

Understanding *why* a query matters helps you pick the right tool. High-volume navigational searches like upc lookup (22K+), upc code lookup (15K+), and barcode lookup (12K+) expect an instant free tool. Commercial queries such as barcode lookup api, upc api, and bulk barcode lookup expect documentation, pricing, and batch endpoints — all available on EcomSource.

Search term	Google impressions	Semrush vol. (est.)	Intent
asin to upc api	139	—	GSC
b2b data api	121	—	GSC
b2b api	52	—	GSC
gtin vs upc	43	—	GSC
upc vs ean vs gtin for selling products online differences how to choose	11	—	GSC
upc code	36	12.1K	Informational
product data api	36	—	GSC
b2b apis	31	—	GSC
amazon api search for products	4	—	GSC
difference between gtin and ean gtin-13 ean-13	1	—	GSC
what's the difference between a gtin and a regular barcode number?	1	—	GSC
amazon product advertising api official 2026	27	—	GSC
amazon api product	26	—	GSC
upc vs ean vs gtin differences for selling products online 2025 or 2026	11	—	GSC
amazon product advertising api current status 2026	22	—	GSC
amazon product data api	22	—	GSC
amazon product advertising api 2026	21	—	GSC
best amazon product data api 2026	20	—	GSC
gtin lookup	—	1.9K	Informational
gtin search	—	1.0K	Informational

Additional long-tail searches in this topic cluster

gtin check digit
gtin-14
gtin vs ean
gtin database
gtin look up
api shoes
go upc api
free barcode lookup api

Free lookup tools on EcomSource.ai

[GTIN lookup tools](/gtin-lookup)
[API lookup tools](/product-data-api)

[All guides & blog posts](/blogs)
[API documentation](/docs)
[Pricing for high-volume barcode lookup](/pricing)

Frequently asked questions

Upc vs ean vs gtin for selling products online differences how to choose?

Searchers looking for upc vs ean vs gtin for selling products online differences how to choose usually need fast, accurate product identification — not a generic description. EcomSource supports this query as part of unified UPC, EAN, GTIN, and ISBN lookup/gtin-lookup with Amazon catalog mapping, variation trees, and bulk batch endpoints. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Product data api?

Product data api is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use product data api to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run product data api free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Amazon api search for products?

Searchers looking for amazon api search for products usually need fast, accurate product identification — not a generic description. EcomSource supports this query as part of unified UPC, EAN, GTIN, and ISBN lookup/gtin-lookup with Amazon catalog mapping, variation trees, and bulk batch endpoints. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Difference between gtin and ean gtin-13 ean-13?

Searchers looking for difference between gtin and ean gtin-13 ean-13 usually need fast, accurate product identification — not a generic description. EcomSource supports this query as part of unified UPC, EAN, GTIN, and ISBN lookup/gtin-lookup with Amazon catalog mapping, variation trees, and bulk batch endpoints. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Amazon product advertising api official 2026?

Amazon product advertising api official 2026 is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use amazon product advertising api official 2026 to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run amazon product advertising api official 2026 free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Amazon api product?

Amazon api product is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use amazon api product to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run amazon api product free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Upc vs ean vs gtin differences for selling products online 2025 or 2026?

Searchers looking for upc vs ean vs gtin differences for selling products online 2025 or 2026 usually need fast, accurate product identification — not a generic description. EcomSource supports this query as part of unified UPC, EAN, GTIN, and ISBN lookup/gtin-lookup with Amazon catalog mapping, variation trees, and bulk batch endpoints. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Amazon product advertising api current status 2026?

Amazon product advertising api current status 2026 is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use amazon product advertising api current status 2026 to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run amazon product advertising api current status 2026 free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Amazon product data api?

Amazon product data api is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use amazon product data api to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run amazon product data api free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Amazon product advertising api 2026?

Amazon product advertising api 2026 is one of the highest-intent searches in product data — and it is exactly what this guide on *GTIN Lookup API* helps you solve. Sellers and developers use amazon product advertising api 2026 to identify products, validate supplier manifests, and connect barcodes to Amazon ASINs. With EcomSource.ai you can run amazon product advertising api 2026 free on the web, via [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb)Chrome Extensionhttps://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb, or through our barcode lookup API/gtin-lookup across 1.6B+ indexed products. Use the free search on [ecomsource.ai](https://www.ecomsource.ai)ecomsource.aihttps://www.ecomsource.ai or read the related sections above for step-by-step workflows tied to API Guide.

Step-by-step: run your first lookup after reading this guide

1Copy a UPC, EAN, GTIN, ISBN, or ASIN from packaging or your supplier sheet.
2Open [ecomsource.ai](/) or a dedicated tool page ([UPC lookup](/upc-lookup), [barcode lookup](/barcode-lookup), [GTIN](/gtin-lookup), [ISBN](/isbn-lookup)).
3Paste the code and search — results include brand, title, images, and Amazon identifiers.
4For lists of 20+ codes, use [bulk barcode lookup](/bulk-barcode-lookup) via the API ([docs](/docs)).
5Pin the [Chrome Extension](https://chromewebstore.google.com/detail/upc-lookup/pglhhlcbcbmfebnagjgmbchpmgokbmpb) for on-page Amazon/Walmart lookups.

Why EcomSource for barcode & UPC data

Competitors excel at single-purpose pages; EcomSource combines free online lookup, Amazon-native ASIN mapping, variation intelligence, and real-time bulk barcode lookup in one platform. If you are outgrowing BarcodeLookup pricing, Go-UPC email bulk turnaround, or EAN-Search rate limits, start with a free account/signup and run your first asin to upc api in seconds.

Try free UPC & barcode lookup →/

Get API keys for bulk search →/signup