I added search to all three of my AI-curated directory sites last month. The choice wasn't obvious — there are at least four options with real adoption — so here's the breakdown I actually ran through before landing on Pagefind.
The four options I considered
Pagefind is a Rust-based static search library. It runs at build time, generates an index in /_pagefind/, and serves everything as static files. No backend, no API key, no per-query billing. It ships a prebuilt UI (PagefindUI) that you can mount on any element, and it supports WebAssembly for in-browser querying.
Algolia DocSearch is free for open-source documentation sites, $49/month for commercial sites below a certain crawl limit. It indexes your content via their crawler (or an API push), stores it on Algolia's infrastructure, and gives you a hosted search widget. Fast, polished, and battle-tested — it's what most major docs sites use.
Lunr.js is a client-side search library. You build the index at build time, serialize it to JSON, and ship it with the page. The browser loads the entire index on first search. Works offline, no external dependency, but the index size grows linearly with content, and there's no incremental loading.
