This script, built entirely using pure JavaScript without any third-party libraries or tools. The script enables easy searching and filtering of one or more JSON data files which share the same key/value formatting structure.

• Load and search multiple json files/datasets.
• Uses flat locally stored files, no database or API (however can be modified for these use cases).
• Effective keyword matching ensuring accuracy and relevancy of results.
• Users can input additional search keywords to further narrow down the search results.
• Also includes ability to sort by JSON keys or values.
• To enhance performance and user experience, the script incorporates an infinite scrolling feature.

The live demo shows a mock product pricing and sale comparison between two stores (using two JSON files/datasets).