Wikipedia Duplicate Reference Detector

This is a small prototype built to demonstrate one of the core ideas behind Lusophone Wishlist Wish 3, detecting when a Wikipedia editor is about to add a reference that already exists in the article. Built by EileenBlessing · Outreachy Round 32.

Article Scanner
Editor Simulation
Enter any Wikipedia article title below. This tool fetches the article using the real Wikipedia API, extracts all references, normalizes URLs, DOIs and ISBNs, and reports which ones appear more than once in the article.
Fetching article...
Error:

Metric Value Notes
Total references found All <ref> tags extracted from article wikitext
Duplicate groups detected
References affected These could be merged or reused
No duplicate references found. All references in this article are unique.
This simulates how the duplicate reference checker would work inside the Wikipedia Visual Editor while an editor is actively editing. Load a real Wikipedia article, then click Cite and enter a URL that already exists in the article to see the duplicate alert.
Loading article references...
Load an article above to begin editing
Once loaded, click Cite in the toolbar to add a new reference. If the reference already exists in the article, a duplicate alert will appear.
References currently in this article (0) — these are checked when you add a new reference

Add a Reference

As you type, this tool checks if the reference already exists in the article.
Duplicate Reference Detected
Existing reference in this article: