Which Pacer Utility Should I Choose?

TanStack Pacer provides five strategies for controlling when operations run. The right choice depends on what should happen to calls that arrive faster than your application can process them.

Compare the utilities

Utility	What happens to frequent calls?	Best fit
Debouncer	Earlier calls are discarded. The latest call runs after activity stops.	Search input, validation, autosave
Throttler	Calls are limited to a steady interval. A trailing call can retain the latest arguments.	Scroll, resize, progress, repeated UI updates
Rate Limiter	Calls run until a quota is reached. Additional calls are rejected until capacity returns.	Client-side quotas and burst limits
Queuer	Calls wait in an ordered buffer and run individually.	Work that must not be lost
Batcher	Items accumulate and run together as one batch.	Bulk requests, writes, and analytics events

Choose by required behavior

Only the final value matters

Use a debouncer. Every call restarts a timer, and the most recent call runs after the activity becomes quiet.

Work should continue at a steady pace

Use a throttler. It limits execution frequency without waiting for activity to stop completely.

A fixed quota must be enforced

Use a rate limiter. It accepts calls until the configured limit is reached, then rejects additional calls within the window.

Every operation must run

Use a queuer. It preserves pending operations and processes them according to FIFO, LIFO, or priority ordering. A finite maxSize can still cause new items to be rejected.

Several items should run together

Use a batcher. It collects items until a size, time, or custom condition triggers one batch execution.

Synchronous or asynchronous

Each utility has a synchronous and asynchronous version. Start with the synchronous version unless the utility must manage Promise-specific behavior.

Use the asynchronous version when you need to:

Await the wrapped function's result.
Track success, error, and settlement state.
Configure error propagation.
Retry failed executions.
Abort in-flight operations.
Run queued tasks concurrently with AsyncQueuer.

Passing an async function to a synchronous utility does not provide these features. The synchronous utility invokes the function but does not await or manage its Promise.

Synchronous	Asynchronous
Debouncing	Async debouncing
Throttling	Async throttling
Rate limiting	Async rate limiting
Queuing	Async queuing
Batching	Async batching

The async utilities use AsyncRetryer internally for retry and abort support.

Core package or framework adapter

Use @tanstack/pacer when you need the core classes and functions without component lifecycle integration.

Use a framework adapter in an application that needs automatic cleanup and reactive state:

Framework adapters provide several API shapes around the same underlying utility:

Instance APIs such as useDebouncer expose lifecycle methods and selected state.
Callback APIs such as useDebouncedCallback return a function to call.
State and value APIs connect the utility to framework state.

Choose the narrowest API that provides the control you need. Use the instance API when you need methods such as cancel() or flush().

Pacer Lite or Pacer

@tanstack/pacer-lite is intended for libraries that need smaller, non-reactive utilities. It omits TanStack Store integration, framework adapters, Devtools support, and some advanced options.

Use the regular core package or a framework adapter for application code. Consider Pacer Lite when bundle size is the primary constraint and reactive state is unnecessary.