Direct comparison
ISSN vs. eISSN: What's the Difference?
ISSN is a print edition's identifier; eISSN is the online edition's own distinct 8-digit code — not a format variant of one number.
Side-by-side comparison
| Dimension | ISSN (Print) | eISSN (Online) |
|---|---|---|
| What it identifies | The print edition of a continuing serial title | The online/electronic edition of the same serial title |
| Governing standard | ISO 3297 | ISO 3297 (same standard, separate registration) |
| Format | 8 digits, NNNN-NNNC, modulus-11 check digit | 8 digits, NNNN-NNNC, modulus-11 check digit — same format, different digits |
| Assigned by | National ISSN Centre (or ISSN International Centre / CIEPS directly) | Same assigning body, as a separate registration for the online medium |
| Same code as its counterpart? | No — a distinct code from the eISSN | No — a distinct code from the print ISSN |
| If only one edition exists | Print-only title: only an ISSN is registered | Online-only title: only an eISSN is registered, and it typically also serves as the ISSN-L |
| Linking mechanism | Conventionally designated the ISSN-L when a print edition exists | Not usually the ISSN-L when a print counterpart exists, but can be if the title is online-only |
| Implies peer review or quality? | No | No |
Common questions
FAQ
Is eISSN just the ISSN written differently for online use?+
No. eISSN is a separate, independently assigned eight-digit code — not a reformatted version of the print ISSN. A title published in both editions genuinely has two different numbers.
Can a journal have an eISSN but no print ISSN?+
Yes. An online-only journal is registered once, for the online medium, and that single eISSN typically also functions as the title's ISSN-L since there's no print edition to link to.
Which number should I cite, ISSN or eISSN?+
Cite whichever matches the edition you used if a style requires it specifically; use the ISSN-L when a single number needs to represent the title regardless of format.
Do ISSN and eISSN ever end up as the same digits?+
No — they're assigned independently and there's no mechanism that produces a matching pair by design; an apparent match would be a data error worth reporting.
Going deeper
