GS1 Digital Link Validator

GS1 Digital Link Validator — Frequently Asked Questions

What does this GS1 Digital Link validator check?

It reads the URI in three passes. Structure first: where the GS1 identifier sequence begins, so a path prefix such as /products/01/… is accepted while a URL that merely looks like a Digital Link is not. Then identity: the primary key must be one of the sixteen listed in the reference table above, and on the fixed-length numeric keys the check digit is worked out again from the digits in front of it rather than taken on trust — two transposed digits are the usual way a link ends up pointing at somebody else's product. Then values, each against the rule its own AI carries: GS1 character set 82 — letters, digits and twenty punctuation marks, with any text field capped at 20 characters — the digit counts the numeric fields allow, and dates that have to land on a day that exists. What comes back is every application identifier decoded with its label, a list of errors and warnings, and — as long as there are no errors — the canonical form to copy, with the GTIN padded to 14 digits and the qualifiers back in the order the standard fixes. Warnings don't withhold it; the rewrite is how you clear them.

Can I check a QR code that's already printed on my packaging?

Yes. Drop in a photo or a screenshot of the symbol, or pick an image file, and the code is read and its URI validated like any other. The decoding runs on your own device — the image is never uploaded, and the decoder is only fetched once you actually hand over an image, so pasting a URI never downloads it. Images up to 10 MB are accepted and anything larger than 2,000 pixels on its longest side is scaled down before reading, which costs nothing in accuracy at QR densities. Both normal and inverted symbols are attempted, so light-on-dark printing is fine. If nothing is found, the usual culprit is a glossy label shot at an angle: crop closer to the symbol and use even, flat lighting.

Is the validator free, and do I need an account?

It's free, there's no account, and there's no usage cap — check as many URIs as you like. Parsing runs entirely in your browser: the URI you paste is never sent to our servers, logged, or stored, and neither is any image you drop in for decoding. The one limit is on length. Anything over 4,096 characters is rejected as a paste accident, which is far beyond what a QR symbol could carry anyway.

What's the difference between an error and a warning?

An error means the URI is not a conformant GS1 Digital Link and a scan can fail or return the wrong product: a check digit that doesn't recompute, no recognised primary key in the path, a second primary key, a qualifier that doesn't belong to the key it follows, or a value that breaks its format. A warning means the link still resolves but drifts from the canonical form the standard asks for — a GTIN that hasn't been padded to 14 digits, a data attribute in the path instead of the query string, qualifiers out of the fixed order, http instead of https, an uppercase host, or an application identifier we don't recognise. The canonical rewrite is only offered when there are no errors left.

Why does my GTIN need to be 14 digits?

The Digital Link URI syntax always expresses AI 01 in its 14-digit form, so a GTIN-8, GTIN-12, or GTIN-13 is left-padded with zeros. Padding never changes the check digit, which is why the validator accepts the short form and shows you the padded version instead of failing it — a warning rather than an error. Print the padded version: it is the form the canonical rewrite hands back, and the one the syntax defines.

Can it decode a compressed GS1 Digital Link?

No. A compressed Digital Link packs every application identifier into a single encoded path segment to save QR modules. The validator recognises that shape and says so explicitly, rather than reporting a confusing "no GS1 identifier" error, but it can't expand it. Paste the uncompressed form to check it.

Which application identifiers are supported?

Sixteen primary keys (GTIN, SSCC, GMN, GRAI, GIAI, GDTI, GCN, GINC, GSIN, CPID, ITIP, the location, party and pay-to GLNs, and the provider and recipient GSRNs), all seven key qualifiers defined by the standard, and the data attributes most likely to appear on packaging — the six date and date-time AIs, internal product variant, variable count, net weight in kilograms, country of origin, TPX, customer part number, and the national healthcare reimbursement numbers for Germany, France, Spain, Brazil and Portugal. The reference table above lists every one, with the path alias shown for the keys and qualifiers that have one — the standard defines no aliases for data attributes, so those are addressed by their numeric AI. An AI outside that set is flagged as unrecognised so you can double-check it instead of assuming it passed.

The link is valid — how do I turn it into a QR code?

The validator only reads a URI; it doesn’t render one. Paste the canonical form into the GS1 Digital Link QR code generator, or let that page assemble the URI for you from the GTIN and optional batch, serial, variant and expiry fields. GS1 codes are static on QRKIT, so no scan limit applies and downloads carry no watermark on any plan: designing and previewing need no account, and downloading the image needs a free one. For a whole catalogue, bulk generation from a CSV with one row per SKU is available on the Plus, Pro and Ultra plans.

Does a valid Digital Link mean my packaging is Sunrise 2027 ready?

It means the data carrier is right, which is the part this tool can check. Sunrise 2027 also depends on things outside the URI: your GTINs being licensed through your local GS1 member organisation, the resolver at your domain answering correctly, and the symbol being printed at a readable size with adequate quiet zone and contrast. See the generator page for what Sunrise 2027 actually requires.