Walidator ISSN: Sprawdz numery publikacji seryjnych

What Is an ISSN?

An ISSN (International Standard Serial Number) is an 8-digit code used to uniquely identify serial publications such as journals, magazines, newspapers, and periodicals. Managed by the ISSN International Centre in Paris, the system ensures that every continuing publication has a distinct identifier.

Unlike ISBNs (which identify specific book editions), ISSNs identify a serial title as a whole. Each medium of the same publication receives its own ISSN — the print version and online version of a journal have different ISSNs.

ISSN Format and Structure

An ISSN consists of 8 digits displayed in two groups of four, separated by a hyphen: XXXX-XXXY where Y is the check digit.

• The first seven digits are assigned sequentially by the ISSN Centre — they do not encode any meaning about the publication
• The eighth digit is a check digit calculated using modulo 11, which can be 0-9 or X (representing 10)
• ISSNs are typically displayed with the prefix ISSN followed by the number: ISSN 2049-3630

How ISSN Validation Works

ISSN validation verifies the format and checks that the mathematical check digit is correct.

• Format check — the ISSN must contain exactly 8 characters (7 digits plus a check character), optionally separated by a hyphen after the fourth digit
• Check digit calculation — multiply each of the first 7 digits by weights 8, 7, 6, 5, 4, 3, 2 respectively. The check digit is the value that makes the sum divisible by 11
• Check digit values — when the remainder calculation yields 10, the check digit is represented as X (uppercase only)

Common Use Cases

ISSN validation supports library science, publishing, and academic research workflows.

• Library cataloging — librarians use ISSNs to identify and catalog serial holdings, preventing confusion between similarly-titled publications
• Citation databases — academic databases like Scopus, Web of Science, and PubMed use ISSNs to index and link journal articles
• Subscription management — publishers and distributors use ISSNs to manage subscription fulfillment and renewals
• Open access repositories — ISSN is used to link preprints and open access articles to their parent journals

ISSN-L and Linking

ISSN-L (Linking ISSN) connects different media versions of the same serial publication.

• A single publication available in print (ISSN for print) and online (ISSN for online) receives an ISSN-L that links both
• The ISSN-L is typically the ISSN of the first published medium — it serves as the canonical identifier
• ISSN-L enables discovery across formats: searching by ISSN-L returns all media versions of the publication

Frequently Asked Questions

Does every blog or website need an ISSN?

No. ISSNs are intended for ongoing serial publications with a clear editorial process — journals, magazines, newspapers, annual reports. Personal blogs, company websites, and one-off publications do not qualify for ISSN assignment.

Can an ISSN have X as the last digit?

Yes. Like ISBN-10, the ISSN check digit is calculated modulo 11. When the check digit calculation yields 10, it is represented as X. For example, ISSN 0378-595X is a valid ISSN.

How do I get an ISSN for my publication?

Apply through your national ISSN centre. The application is free in most countries. You will need to provide details about the publication title, publisher, frequency, and medium (print or online).