On the Feasibility and Implications of Self-Contained Search Engines in the Browser

TL;DR

This paper investigates the potential of building a fully self-contained JavaScript search engine within browsers, leveraging browser APIs like IndexDB, to enable offline, private, and hybrid search applications despite performance limitations.

Contribution

It demonstrates the feasibility of client-side search engines using JavaScript and browser APIs, highlighting new possibilities for offline and privacy-preserving search architectures.

Findings

Prototype is responsive enough for interactive use

Performance is lower than traditional search engines like Lucene

Enables offline, private, and hybrid search applications

Abstract

JavaScript engines inside modern browsers are capable of running sophisticated multi-player games, rendering impressive 3D scenes, and supporting complex, interactive visualizations. Can this processing power be harnessed for information retrieval? This paper explores the feasibility of building a JavaScript search engine that runs completely self-contained on the client side within the browser---this includes building the inverted index, gathering terms statistics for scoring, and performing query evaluation. The design takes advantage of the IndexDB API, which is implemented by the LevelDB key-value store inside Google's Chrome browser. Experiments show that although the performance of the JavaScript prototype falls far short of the open-source Lucene search engine, it is sufficiently responsive for interactive applications. This feasibility demonstration opens the door to interesting applications in offline and private search across multiple platforms as well as hybrid split-execution architectures whereby clients and servers collaboratively perform query evaluation. One possible future scenario is the rise of an online search marketplace in which commercial search engine companies and individual users participate as rational economic actors, balancing privacy, resource usage, latency, and other factors based on customizable utility profiles.