switchMap vs mergeMap

Updated May 6, 2026

Short answer

switchMap cancels previous; mergeMap runs all concurrently.

Deep explanation

switchMap is ideal for latest-only requests.

Real-world example

Search autocomplete API calls.

Common mistakes

  • Using mergeMap when cancellation is needed.

Follow-up questions

  • What is concatMap?
  • Which is fastest?

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