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Vitest · Method

vi.useFakeTimers

vi.useFakeTimers replaces supported timer APIs with fake ones that tests can control. It keeps them mocked until vi.useRealTimers() is called.

Last updated 2 November 2026

Syntax

function useFakeTimers(config?: FakeTimersConfig): Vitest

In-depth API docs are only for subscribers: parameters, examples, common mistakes and interview practice.

vi.useRealTimers
vi.advanceTimersByTime
vi.runAllTimers
vi.runAllTimersAsync
vi.setTimerTickMode
fakeTimers.now
fakeTimers.toFake
fakeTimers.toNotFake

Source: Vi | Vitest. Checked 2026-11-03.