Yes, requests to a Query Suggestions index are billed like any other search request. But whether they increase your total depends on how your frontend is built.
Query Suggestions requests are ordinary search requests
A Query Suggestions index is a normal Algolia index. When your application queries it, that call is counted as a billable search request, exactly as a query to any other index would be. See How Algolia counts search requests, operations, and records.
The question that matters for your bill is therefore not "are suggestions billable" but "how many network calls does each keystroke produce".
One request per keystroke (recommended)
You can retrieve both suggestions and result hits in a single request by bundling the two queries, which the Autocomplete library does using multi-query under the hood.
In this example, the Network tab shows only one call per keystroke, even though results come back from both the hits index and the suggestions index. That is one billable search request per keystroke for two indices.
Two requests per keystroke
In implementations where the suggestions menu and the results list are separate components, for example an Autocomplete menu handling suggestions alongside InstantSearch handling hits, each component issues its own request. That is two billable search requests per keystroke.
Summary
- Query Suggestions are billable search requests.
- Bundling suggestions and hits into one request keeps you at one billable request per keystroke, even across two indices.
- Your frontend implementation, not the use of Query Suggestions itself, determines whether your request volume goes up.