﻿---
title: The refresh parameter
description: The Index, Update, Delete, and Bulk APIs support setting refresh to control when changes made by this request are made visible to search. These are the...
url: https://www.elastic.co/elastic/docs-builder/docs/2841/reference/elasticsearch/rest-apis/refresh-parameter
products:
  - Elasticsearch
applies_to:
  - Elastic Stack: Generally available
---

# The refresh parameter
The [Index](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-create), [Update](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-update), [Delete](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-delete), and [Bulk](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-bulk) APIs support setting `refresh` to control when changes made by this request are made visible to search. These are the allowed values:
<definitions>
  <definition term="Empty string or true">
    Refresh the relevant primary and replica shards (not the whole index) immediately after the operation occurs, so that the updated document appears in search results immediately. This should **ONLY** be done after careful thought and verification that it does not lead to poor performance, both from an indexing and a search standpoint.
  </definition>
  <definition term="wait_for">
    Wait for the changes made by the request to be made visible by a refresh before replying. This doesn’t force an immediate refresh, rather, it waits for a refresh to happen. Elasticsearch automatically refreshes shards that have changed every [`index.refresh_interval`](/elastic/docs-builder/docs/2841/reference/elasticsearch/index-settings/index-modules#index-refresh-interval-setting).
    Calling the [Refresh](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-indices-refresh) API or setting `refresh` to `true` on any of the APIs that support it will also cause a refresh, in turn causing already running requests with `refresh=wait_for` to return.
    <note>
      In Elastic Stack, the default value for `index.refresh_interval` is `1s`.
      In Elastic Cloud Serverless, the default value for `index.refresh_interval` is `5s`.
      The `index.refresh_interval` setting is [dynamic](https://www.elastic.co/elastic/docs-builder/docs/2841/reference/elasticsearch/index-settings).
    </note>
  </definition>
  <definition term="false (the default)">
    Take no refresh related actions. The changes made by this request will be made visible at some point after the request returns.
  </definition>
</definitions>


## Choosing which setting to use

Unless you have a good reason to wait for the change to become visible, always use `refresh=false` (the default setting). The simplest and fastest choice is to omit the `refresh` parameter from the URL.
If you absolutely must have the changes made by a request visible synchronously with the request, you must choose between putting more load on Elasticsearch (`true`) and waiting longer for the response (`wait_for`). Here are a few points that should inform that decision:
- The more changes being made to the index the more work `wait_for` saves compared to `true`. In the case that the index is only changed once every `index.refresh_interval` then it saves no work.
- `true` creates less efficient indexes constructs (tiny segments) that must later be merged into more efficient index constructs (larger segments). Meaning that the cost of `true` is paid at index time to create the tiny segment, at search time to search the tiny segment, and at merge time to make the larger segments.
- Never start multiple `refresh=wait_for` requests in a row. Instead batch them into a single bulk request with `refresh=wait_for` and Elasticsearch will start them all in parallel and return only when they have all finished.
- If the refresh interval is set to `-1`, disabling the automatic refreshes, then requests with `refresh=wait_for` will wait indefinitely until some action causes a refresh. Conversely, setting `index.refresh_interval` to something shorter than the default like `200ms` will make `refresh=wait_for` come back faster, but it’ll still generate inefficient segments.
- `refresh=wait_for` only affects the request that it is on, but, by forcing a refresh immediately, `refresh=true` will affect other ongoing request. In general, if you have a running system you don’t wish to disturb then `refresh=wait_for` is a smaller modification.


## `refresh=wait_for` can force a refresh

If a `refresh=wait_for` request comes in when there are already `index.max_refresh_listeners` (defaults to 1000) requests waiting for a refresh on that shard then that request will behave just as though it had `refresh` set to `true` instead: it will force a refresh. This keeps the promise that when a `refresh=wait_for` request returns that its changes are visible for search while preventing unchecked resource usage for blocked requests. If a request forced a refresh because it ran out of listener slots then its response will contain `"forced_refresh": true`.
Bulk requests only take up one slot on each shard that they touch no matter how many times they modify the shard.

## Examples

These will create a document and immediately refresh the index so it is visible:
```json

{"test": "test"}

{"test": "test"}
```

These will create a document without doing anything to make it visible for search:
```json

{"test": "test"}

{"test": "test"}
```

This will create a document and wait for it to become visible for search:
```json

{"test": "test"}
```