Building a Full-Text Search Engine Inside .NET MAUI with SQLite's FTS5 Extension

LIKE '%query%' and in-memory filtering fall apart as your data grows — they’re slow, unranked, and memory-hungry. This guide implements a production-ready, fully offline search engine in .NET MAUI using SQLite FTS5 for indexing and Shaunebu.Data.SQLite for clean, async, thread-safe data access.

What you’ll learn

• Why FTS5 beats traditional search: tokenization, prefix and phrase matching, BM25 relevance ranking, and blazing-fast offline queries
• What Shaunebu.Data.SQLite brings: a thread-safe singleton per database, async CRUD and batch operations, and fluent LINQ-style queries
• Step-by-step: defining a searchable model, creating the FTS5 virtual table, and keeping the index in sync automatically with triggers
• Batch inserts wrapped in transactions, running full-text queries, and binding search to a MAUI ViewModel and UI
• Performance best practices (index only what you search, limit results, prefer prefix search, avoid leading wildcards) and ideal use cases

Well worth a look if your MAUI app needs serious, offline search.