Duplicate ID Remover: The Tiny Tool That Saves Big Headaches
Duplicate IDs in XML or HTML are subtle, easy to create, and surprisingly hard to find manually. This tool finds them in seconds.
In XML and HTML, an ID is supposed to be unique. One element, one ID. The whole point is that an ID lets you point precisely at one specific element — a link target, a script reference, a stylesheet anchor.
Duplicate IDs break this assumption silently. The document still looks valid. Browsers and parsers often don't error on them. But behavior becomes unpredictable: which element gets styled? Which one gets focused? Which one gets returned by getElementById?
Duplicate IDs usually appear during copy-paste operations (duplicating a section and forgetting to update the ID), automated generation (template systems that generate IDs without checking uniqueness), and merging (combining two documents without reconciling their ID spaces).
The Duplicate ID Remover finds every duplicate, shows you where each one appears, and gives you options: remove all duplicates automatically (keeping the first occurrence), rename them with sequential suffixes, or just show you a report so you can fix them manually.
This tool took one day to build. It has saved people weeks of debugging. Sometimes the smallest tools have the biggest impact.