ISSN
GET/v0/issn
Validates an International Standard Serial Number (ISSN) — the global identifier assigned to periodical publications such as journals, magazines and newspapers. Accepts the standard XXXX-XXXX format as well as the 8-character form without a hyphen. The check digit (last character, which may be 0–9 or X for 10) is verified using a mod-11 weighted sum. Spaces and hyphens are stripped automatically before validation.
Try it
Query Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
| value | string | Yes | The ISSN to validate (with or without hyphen, e.g. 0378-5955 or 03785955) |
Example Request
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://api.isvalid.dev/v0/issn?value=0378-5955"
Response Fields
| Field | Type | Description |
|---|---|---|
| valid | boolean | Whether the ISSN passed check digit validation |
| issn | string | Normalized ISSN in the canonical XXXX-XXXX format. Present only when valid is true |
Example Response
{
"valid": true,
"issn": "0378-5955"
}Example Response — invalid
{
"valid": false
}