Commons:Cross-wiki media upload tool
The Cross-wiki media upload tool is a upload tool available in VisualEditor and wikitext editor which allows the remote upload of files from any Wikimedia wiki to Wikimedia Commons. Uploaded files are tagged as Cross-wiki upload in the recent changes.
The tool is affected by a severe long-standing bug: upload of files bigger than 5 MB is broken with reaching of this limit!
- mw:Upload dialog - Extended documentation at MediaWiki.org