Zotero ISBN lookup fails, DOI works

Hekkens · 2026-03-14T14:04:40+00:00

Hello,

“Add Item by Identifier” fails for ISBNs, but DOI lookup works.

Example ISBN that fails:
9789403189215

Error message:
“Zotero could not find an item for the specified identifier. Please verify the identifier and try again.”

DOI lookup works when I enter only the DOI itself.

I tested this on Windows 10 and on Android, and it also fails on mobile data, so it does not seem to be limited to my Wi-Fi connection.

Debug ID:
D1883996170

Could you please check what is failing in the ISBN lookup?

Thank you.

Hekkens · 2026-03-18T13:31:11+00:00

Update: no updates are available, and I have no plugins installed. DOI lookup works, but ISBN lookup still fails. The problem still persists.

Hekkens · 2026-03-18T14:00:43+00:00

Update: ISBN lookup is not completely broken. An English-language book ISBN worked, but Dutch book ISBNs still fail. I also tested a Dutch Bible, which also failed.

adamsmith · 2026-03-18T16:04:39+00:00

There is no standard database of ISBNs as there is for (almost all) DOIs. Zotero does lookup in a range of library catalogs (I'd have to check the full list, but it includes the Library of Congress, the German K10+ catalog, the Bibliotheque de France and I believe Polish and Brazilian catalogs for for Polish/Brazilian ISBN ranges - the ability to do so for a given country depends on the availability of decent APIs.
Zotero does try to look in Worldcat (which does have the above ISBN/book), but since Worldcat is using very aggressive anti-bot measures, that often fails.

tresor700 · 2026-03-19T02:03:43+00:00

I also have this issue on my Macbook. I've tried to reinstall the program but the error keeps showing up. ISBN number doesn't work, but DOI works fine tho.

https://s3.amazonaws.com/zotero.org/images/forums/u16658904/x2priqj1tsvdm5qb2t4y.png

dstillman · 2026-03-19T02:05:43+00:00

@tresor700: It has nothing to do with your installation. WorldCat has just gotten more aggressive at blocking automated lookups of ISBNs, so ISBNs for which there isn't metadata elsewhere sometimes can't be resolved at the moment.

Hekkens · 2026-03-20T11:57:51+00:00

Thanks for the explanation — that helps, and it matches what I’m seeing in practice. One English-language ISBN worked, while several Dutch book ISBNs failed.

Would it be possible for Zotero to use a Dutch source such as Bureau ISBN / CB as an additional fallback for Dutch ISBNs, if they offer suitable metadata access? Since Dutch books used to work much better for me a few months ago, I’m wondering whether the recent WorldCat anti-bot issues are now affecting Dutch ISBN lookup disproportionately.

adamsmith · 2026-03-20T12:13:28+00:00

Bureau ISBN and similar services don't offer metadata lookup. KB does offer a lookup, but it returns a quirky metadata format (DCX, an extended Dublin core) so would require some work