ISSN Barcode Generator is a lightweight, browser-based publishing utility for turning a standard eight-character ISSN into the EAN-13 / GTIN-13 barcode structure used for serial publications. It is designed for magazine publishers, journal teams, independent editors, designers, prepress operators, and anyone who already has an ISSN and needs a usable barcode asset for a publication layout. The project runs as a static website and is intended for deployment on GitHub Pages without a server, database, user account, or build pipeline.
The tool focuses on the complete task rather than asking the user to calculate barcode data manually. A user can enter a familiar value such as 0317-8471; the page validates the ISSN check digit, removes the ISSN check digit from the encoded base, adds the 977 serial-publication prefix, appends a two-digit publisher variant, calculates a new GTIN-13 check digit, and renders the result as an EAN-13 barcode. Optional two-digit and five-digit issue add-ons are available for workflows that use supplementary issue information.
The application accepts formatted or unformatted ISSNs, including values whose ISSN check digit is X. It normalizes spaces, hyphens, and an optional leading ISSN label before validation. Validation uses the ISSN Mod-11 rule with weights from 8 through 2 on the first seven digits. When the ISSN is valid, the application constructs the serial-publication GTIN with the structure 977 + first seven ISSN digits + two-digit publisher variant + GTIN check digit.
The GTIN check digit is calculated with the standard alternating Mod-10 weighting used for GTIN-13. The page shows the normalized ISSN, a readable structure such as 977 | 0317847 | 00 | 1, and the final GTIN-13. This makes the transformation visible rather than presenting only an unexplained barcode image.
Barcode drawing is dependency-free. The project contains its own EAN-13 encoding tables and the parity logic used by EAN-13, EAN-2, and EAN-5. The SVG renderer adds quiet space around the main symbol, creates the optional supplement beside it, and includes human-readable ISSN and GTIN text. Users can download the generated vector SVG or export a high-resolution PNG from the browser.
- Open the site in a modern browser.
- Enter an ISSN such as
0317-8471,03178471, orISSN 0317-8471. - Review the inline status beside the field. A valid ISSN immediately produces the GTIN and barcode. If the ISSN check digit does not match, the page displays the check digit expected from the first seven digits.
- Keep the publisher variant at
00for the common default workflow, or enter another two-digit value from00through99when your publishing workflow assigns a different variant. - Choose
None,2 digits, or5 digitsunder Issue add-on. When an add-on is selected, enter exactly the requested number of numeric characters. - Confirm the GTIN structure and final GTIN-13 shown below the preview.
- Use Copy to place the GTIN-13 on the clipboard, Download SVG for a scalable vector file, or Download PNG for a raster image.
- Place the exported asset into your page-layout, illustration, publishing, or prepress workflow.
The interface updates while the user types and does not use disruptive browser alert dialogs. Desktop screens use a two-column layout so inputs and output are visible together. Mobile screens automatically stack the same controls into a single-column workflow.
- Formatted ISSN:
0317-8471 - Compact ISSN:
03178471 - ISSN with label:
ISSN 0317-8471 - ISSN with an
Xcheck digit, for example1050-124X - Two-digit publisher variants from
00to99 - Optional two-digit EAN add-on
- Optional five-digit EAN add-on
- Live EAN-13 barcode preview
- EAN-13 with optional EAN-2 supplement
- EAN-13 with optional EAN-5 supplement
- SVG download
- PNG download
- Copyable GTIN-13 text
SVG is the preferred editable output because it remains vector-based when resized in compatible design software. PNG export is generated at a higher raster scale for convenient placement in applications that prefer bitmap images.
The site uses semantic HTML5, responsive CSS, and native JavaScript ES modules. There are no runtime package dependencies. js/issn.js contains deterministic ISSN and GTIN calculations. js/barcode.js contains the EAN digit patterns, first-digit parity rules for EAN-13, two-digit supplement modulo-4 parity, five-digit supplement checksum/parity logic, and SVG rendering. js/app.js connects these pure functions to the interface and implements copy and download actions.
The PWA manifest provides standalone installation metadata and 192-pixel, 512-pixel, and SVG application icons. sw.js pre-caches every runtime local asset needed by the page. On later requests it follows a network-first strategy: the service worker requests the server version first, stores a successful same-origin response in the current cache, and uses the cached response when the network request fails. This keeps normal visits fresh while preserving an offline fallback after a successful visit.
Automated tests use Node.js's built-in test runner, so no npm dependencies are required for verification. Tests cover ISSN normalization, numeric and X check digits, invalid ISSN detection, the known 0317-8471 conversion to 9770317847001, publisher variants, GTIN check digits, EAN-13 module structure, EAN-2 parity, EAN-5 parity, SVG output, SEO requirements, PWA asset coverage, README length, and repository configuration.
issn-barcode-generator/
├── index.html
├── css/
│ └── styles.css
├── js/
│ ├── app.js
│ ├── barcode.js
│ └── issn.js
├── icons/
│ ├── icon.svg
│ ├── icon-192.png
│ └── icon-512.png
├── tests/
│ ├── barcode.test.mjs
│ ├── issn.test.mjs
│ └── static-check.test.mjs
├── docs/
│ └── superpowers/
├── manifest.json
├── sw.js
├── repo.config.json
├── package.json
├── LICENSE
└── README.md
The repository intentionally does not contain a .github directory. No generated dist folder is needed because GitHub Pages can serve the source files directly.
The project has no production build step. For GitHub Pages, push the repository to GitHub, use the main branch as the default branch, and configure Pages to publish the repository root. The expected production URL is:
https://yeshan-jun.github.io/issn-barcode-generator/
The canonical tag in index.html, the PWA paths, and the repository configuration are already aligned with this URL structure. Because all runtime paths are relative, the application also works from a local static HTTP server during development. For a quick local test, run a static server in the repository directory and open its local address in a browser. Run npm test before deployment to execute all automated checks.
The intended GitHub repository is:
https://github.com/yeshan-jun/issn-barcode-generator
Repository metadata is stored in repo.config.json. It specifies the public visibility, GitHub Pages homepage, default main branch, source stack, Pages stack, and focused topics such as ISSN, EAN-13, GTIN-13, magazine barcodes, journal publishing, and PWA.
Barcode generation happens locally in the browser. The application does not require a user account, backend endpoint, analytics API, database, or file upload. ISSN values entered into the form are processed by local JavaScript to validate the identifier, calculate the GTIN, and render the barcode. The service worker stores only the site's static runtime resources in the browser cache for offline use.
This project is released under the MIT License.
See the LICENSE file for the full license text.
The implementation and project documentation were designed around the following standards and technical references:
- ISSN International Centre — Identification with the EAN-13 barcode:
https://www.issn.org/understanding-the-issn/issn-uses/identification-with-the-ean-13-barcode/ - Library of Congress — ISSN check digit basics:
https://www.loc.gov/issn/basics/basics-checkdigit.html - GS1 — GTIN check digit calculation:
https://www.gs1.org/services/how-calculate-check-digit-manually - GS1 General Specifications — EAN/UPC two-digit and five-digit add-on structures and parity rules.
These references define the identifier transformation and barcode structures implemented by the project. The automated test suite preserves known examples and structural checks so later changes can be verified before deployment.