TL;DR: We are removing the PHP‑serialized output format from Special:EntityData on May 28. URLs like Q42.php and Accept: application/vnd.php.serialized requests will stop working. Please switch to JSON (example Q42.json) instead.

Hi everyone,

We are making a significant change to the LinkedData interface on Wikidata. Starting May 28, the Special:EntityData page will no longer support the PHP‑serialized output format.

This means

• URLs like https://www.wikidata.org/wiki/Special:EntityData/Q42.php will return an error (HTTP 415 Unsupported Media Type).

• Requests like https://www.wikidata.org/wiki/Special:EntityData/Q42 with the Accept: application/vnd.php.serialized header will return an error (HTTP 406 Not Acceptable).

Why are we removing this format?

• The PHP‑serialized format is not a stable or standardised data format. It can only be used by PHP applications and poses potential security risks.

• Maintaining it adds unnecessary complexity and technical debt.

• Usage is extremely low (approx. 2000 requests per day, mostly from bots), especially compared to JSON (millions) and RDF/Turtle (tens of millions).

What should you use instead?

Please use the JSON format, which is fully supported and stable. For example: https://www.wikidata.org/wiki/Special:EntityData/Q42.json

For more details on all available formats and how to access them, see the Linked Data Interface section of the Data access page.

Timeline

• May 20: The change is deployed to Test Wikidata and the Beta cluster, where you can already test the new behaviour.

• May 22: This announcement

• May 28: The change will be deployed to Wikidata production.

If you have any questions or concerns, please write directly on the Phabricator task (phab:T98035).

Cheers,