Differences between multi-search and federated search

This article defines multi-search and federated search and then describes the different uses of each.

Multi-search, also called multi-index search, is a search operation that makes multiple queries at the same time. These queries may target different indexes. Meilisearch then returns a separate list results for each query. Use the /multi-search route to perform multi-searches.

Multi-search favors discovery scenarios, where users might not have a clear idea of what they need and searches might have many valid results.

Federated search is a type of multi-index search. This operation also makes multiple search requests at the same time, but returns a single list with the most relevant results from all queries. Use the /multi-search route and specify a non-null value for federation to perform a federated search.

Federated search favors scenarios where users have a clear idea of what they need and expect a single best top result.

Because multi-search groups results by query, it is often useful when the origin and type of document contain information relevant to your users. For example, a person searching for shygirl in a music streaming application is likely to appreciate seeing separate results for matching artists, albums, and individual tracks.

Federated search is a better approach when the source of the information is not relevant to your users. For example, a person searching for a client's email in a CRM application is unlikely to care whether this email comes from chat logs, support tickets, or other data sources.