Sustainable Identity on Every Thing

Sustainable Identity Generator
for Every Thing

QSeq mints Barcodes, QR Codes and Data Matrix carriers for SGTINs, GS1 Digital Links and EPC URIs — with a print-true physical-size calculator so what you design is exactly what prints.

Open QSeq Download for macOS Download for Windows

Native macOS app (Apple silicon, signed & notarized) & Windows x64 · the Windows build is also signed and SmartScreen reputation is accruing — click “More info → Run anyway” past SmartScreen · © 2026 Meerv Inc.

Codes & Labels App

Label designer Serialization Workspace Data source GS1 identifier type

GTIN (Global Trade Item Number) — identifies a trade item (a product or service) at any packaging level, from a single retail unit to a case or pallet. Structure: GS1 Company Prefix + Item Reference + 1 check digit (8, 12, 13 or 14 digits total). SGTIN adds an optional alphanumeric Serial (≤20 chars, AI 21) when Serialization is on.

GTIN length GTIN-14

✓ check digit valid

Serial Format Resolver Digital Link domain

https://id.gs1.org/01/80614141123458/21/6789

2D symbology Error correction

Resolution (DPI) X-dimension (mm)

Rulers

Show rulers around the preview Include rulers in the PDF export

Logo

Outer size

20.8 × 34.9 mm

0.82 × 1.37 in

At 300 DPI

246 × 412 px

Geometry

Version 4 · 33×33 modules

Bytes

44 / 62

Module 6 dots @ 300 DPI · print at 300 DPI for exact size

Why this is source-available

QSeq is released as source-available (PolyForm Noncommercial) to accelerate the transition to Sustainable Identity on Every Thing: a future where every physical object carries an open, web-resolvable, standards-based identity — GS1 Digital Links, SGTINs and compatible carriers — that anyone can read, verify and build upon without proprietary lock-in.

Durable, interoperable identity is the foundation of the circular economy. Reuse, repair, recall, provenance and end-of-life tracking all depend on a code that still resolves years after it was printed. Keeping the tools that mint those identities open means the infrastructure of identity stays a public good — not a toll booth.

Standards-first

GS1 Digital Link, SGTIN, EPC Tag URI, GS1-128, Data Matrix — no bespoke formats.

Print-true

Exact-DPI sizing with mm + inch + vernier rulers so the print matches the intent.

Yours to fork

Raw parameters export to editable JSON. Generate designs from your own pipelines.

Source code

https://github.com/Meerv-Inc/QSeq

Why “QSeq”?

Seq is sequence — QSeq exists to mint ordered, serialized identities. The Q is chosen deliberately: every reading of it lands on exactly what a well-formed sequence of identity codes must be — ordered, robust and resolvable.

Q — Quality factor. In physics, Q measures how well a resonator preserves energy against loss; a higher Q survives more disturbance. A QSeq code is engineered the same way: its error-correction budget and structure-aware dead-space are a literal quality factor for how much damage an identity can take and still resolve.
Q — Time quanta. A quantum is the smallest indivisible step. Serialization advances one quantum at a time — each code is the next discrete tick in the sequence, never skipped, never repeated.
Q — Queue. A queue is an ordered set processed in order. A serialized sheet is a queue of identities, minted and consumed first-to-last.
Q — Cue. A cue is the signal that triggers the next action. Every scannable code is a cue: scan it, it resolves, and the next supply-chain step fires.
Q — QR. And of course the canonical 2D carrier itself begins with Q.

Quality factor, quanta, queue, cue, QR — four meanings and a carrier, each independently true, all pointing to the same idea: a quality-assured, ordered, resolvable sequence of identity codes. That is QSeq.

Why Flutter & Dart?

QSeq is written in Flutter / Dart so a single codebase serves every surface. The macOS and Windows desktop apps are built from it, and the same Dart core powers this website: the web generator now runs the exact encoders and sizing engine as the desktop, compiled to the browser. One implementation of the encoders, capacity tables and sizing math means an identity minted on macOS, Windows or the browser is byte-for-byte the same.

Support

Questions, bug reports or feature requests? We read every message — QSeq is built in the open and we want it to work for you.

Email support@meerv.com and we'll get back to you. Telling us your QSeq version and your platform — macOS, Windows or web — helps us help you faster.

Email support@meerv.com Open a GitHub issue →

What “Sustainable Identity” requires

The phrase is a double condition, and both halves must hold — implicitly, anything that fails either one is outside it.

It must be an Identity. A Stock Keeping Unit (SKU) — or any bare, class-level GTIN — names a kind of thing, not a thing. Unserialized, it is shared by every unit in the batch and can never resolve to the record of this one; it is ultimately not resolvable to a Digital Product Passport. So an SKU is not an Identity. Identity begins at serialization: an SGTIN carried in a web-resolvable GS1 Digital Link, where each physical item resolves to its own passport.
It must be Sustainable. An identity printed in a way that is not sustainable is not sustainable either. A code printed at the wrong physical size, with its error-correction budget spent on a logo, or with no margin left for the scuffs, fading and curvature of real life stops scanning — and an identity that stops resolving takes reuse, repair, recall and end-of-life tracking with it. Print-true sizing and a protected error-correction margin are what let the identity survive as long as the thing it marks.

An SKU alone fails the first condition; a fragile print fails the second. Sustainable Identity on Every Thing means meeting both — and QSeq exists so every code it mints does.

Sister app: QRPic

QRPic is QSeq's sister app — an Android tool that measures exactly how much of a QR code's Reed–Solomon error-correction budget a center logo consumes. Point the camera at a logo'd QR code and QRPic reads its version and error-correction level, maps the modules the logo covers to their codewords and Reed–Solomon blocks, and simulates scaling the logo up or down so you can see — before you print — whether the code still has the recovery headroom to survive real life.

It is the natural companion to QSeq's print-true, error-correction-aware philosophy: QSeq mints sustainable identities; QRPic verifies that a branded code hasn't spent its survival budget on a logo.

Error-budget aware

Maps logo-covered modules to Reed–Solomon codewords and reports erasure-view and field-decoder recovery.

Live from camera

Detects QR symbols with ZXing, reading version, EC level and decoded payload on device (CameraX).

MIT licensed

Unlike QSeq (PolyForm Noncommercial), QRPic is released under the permissive MIT License — free to use, modify and ship commercially.

Download the Android APK Source on GitHub →

Android app (Kotlin + Jetpack Compose, min SDK 24). Prebuilt signed APKs on the GitHub releases page. QR engine: ZXing (Apache-2.0). Released under the MIT License.