> ## Documentation Index
> Fetch the complete documentation index at: https://dev.jup.ag/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Reduce Latency

> Get faster swap quotes with fast mode

Set `mode=fast` on `/build` to reduce routing latency at the cost of quote optimality.

```
GET /build?inputMint=...&outputMint=...&amount=...&taker=...&mode=fast
```

<Note>
  The feature `mode=fast` on `/build` is new and in BETA. Note that there may be changes to the implementation as we continue to improve and evaluate.
</Note>

## How it works

Fast mode optimises for speed in two ways:

* **Bellman-Ford with no splitting:** the routing algorithm uses Bellman-Ford without splitting the route across multiple pools. This reduces computation time significantly, at the cost of potentially missing better multi-pool routes.
* **Parallel priority fee lookup:** the `getRecentPriorityFee` RPC call runs in parallel with the call to Metis routing engine to get the swap instructions, instead of sequentially. This eliminates the RPC round-trip from the critical path.

<Note>
  When the `getRecentPriorityFee` is done in parallel and not sequentially, this can impact the final priority fee estimation.

  When done sequentially, the Metis routing result provides the writable accounts (hot accounts/local fee market) that we will use in `getRecentPriorityFee` to further estimate accurately.

  When done parallelly, those accounts are not yet known, hence `getRecentPriorityFee` will estimate globally based on global fees.
</Note>

## When to use

* You are swapping high-frequency and need low latency
* The pair is well-known (e.g. SOL/USDC) and doesn't benefit from complex routing
* You are building a trading bot where speed matters more than optimising the last basis point

## Trade-offs

Fast mode may return suboptimal pricing compared to the default mode because:

* Less accurate priority fee estimation as mentioned above
* No route splitting means the entire amount goes through a single pool path
* Fewer route combinations are explored

For most major pairs and typical sizes, the pricing difference is negligible. For large swaps or illiquid pairs, the default mode will find better routes.

## Related

* [Reduce Transaction Size](/swap/advanced/reduce-transaction-size) for controlling account count
* [Build](/swap/build) for the full `/build` workflow
* [Transaction Submission](/transaction/submit) to submit via Jupiter's transaction landing infrastructure with SOL tips for priority processing