Check Your Book Metadata Online
Built for publishing editors and metadata managers, this free tool validates your ONIX XML file against the official EDItEUR schemas, groups every problem by book record, and explains what to change — in publishing language, not parser jargon.
Free ONIX file check
Drag your ONIX file here
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Supports ONIX 2.1 / 3.0 / 3.1 · XML, ONX, and ONIX files
No sign-up required. Your file is uploaded over HTTPS, processed temporarily on the validation service, and deleted after validation. Privacy details Maximum file size: 25 MB.
Example report
IllustrativeEvery result starts with a clear file summary, then points you to the affected record, explains why the issue matters, and gives you a safe next step.
2
schema errors
3
quality warnings
42
product records checked
Record 18 · ISBN 9780000000000 · Line 122
This record does not include the title information required for a product listing.
How to repair
Add the required title composite to the affected product record, then validate the exported file again.
ONIX for Books is the international standard XML format for communicating book product metadata. Maintained by EDItEUR, it defines a precise vocabulary for describing titles, contributors, identifiers, prices, territorial rights, and supporting resources so that trading partners can exchange catalog data without manual re-keying.
Publishers create ONIX messages; distributors, wholesalers, retailers, and library suppliers receive them. A single ONIX message contains a header plus one product record per book or format, and each record can carry hundreds of fields — from the ISBN and title to subject classifications, descriptions, and supply terms.
Because the format is strict, a single misplaced element or invalid code can make an entire feed fail. That is why validation matters: errors found here are errors that Amazon, Ingram, and other recipients would otherwise find during ingestion.
This validator supports ONIX 2.1, 3.0, and 3.1 — the versions in active use across the industry — in both reference-tag and short-tag formats.
Schema validation errors. The file breaks the official ONIX specification: unexpected or misspelled elements, elements in the wrong order, missing required elements or composites, and values that violate the format the schema requires (for example a malformed publication date).
Invalid code-list values. ONIX fields such as product form, contributor role, and price type draw from EDItEUR code lists. A value outside the list is meaningless to receiving systems.
ISBN and identifier problems. Our project quality rules flag records with no usable product identifier, ISBNs that fail check-digit rules, and duplicate record references — issues that pass schema validation but break distribution.
Metadata-quality warnings. Clearly separated from official schema errors, these recommendations cover problems like missing titles, contributors without roles, and prices without currencies — the mistakes that cause silent rejections and wrong product pages.
Validation runs against the official XML Schemas for ONIX 2.1, 3.0, and 3.1, bundled with the pinned onixcheck 0.9.11 engine. The engine version and active schema are shown with every report.
Honest limits: a schema-valid file is not guaranteed to be accepted by Amazon, Ingram, Google, or any other channel — recipients apply their own additional rules. This tool does not verify that your metadata is commercially complete, and project warnings are recommendations, not official ONIX errors.
An ONIX validator checks whether an ONIX for Books XML file follows the official EDItEUR schema. It finds structural errors, missing required elements, and invalid code values, and — in this tool — explains each problem in publishing language with repair steps.
The validator supports ONIX 2.1, ONIX 3.0, and ONIX 3.1, in both reference-tag and short-tag formats, validated against the official XSD schemas bundled with onixcheck 0.9.11.
Yes. The file is uploaded over HTTPS so the onixcheck engine and our quality rules can run on it. The file is held only in an isolated temporary location on the validation server while your request is processed.
Your file exists only for the duration of the validation request. This service does not intentionally save uploaded XML files or validation history after processing completes.
Errors come from the official ONIX schema: the file violates the specification and is likely to be rejected by recipients. Warnings are project recommendations about metadata quality — the file is schema-valid, but something is likely to cause problems in distribution.
No. Schema-valid means the file conforms to the official ONIX specification. Retailers and distributors apply their own additional requirements, so a schema-valid file can still be rejected by a specific channel.
Today the validator explains each problem and tells you how to repair it — it never silently changes your metadata. A future version may offer a small set of safe, mechanical fixes with a visible diff and your explicit approval before anything changes.
No sign-up, no installation — validate ONIX 2.1, 3.0, and 3.1 files right here.
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