---
acl_categories:
- '@bloom'
- '@read'
- '@slow'
arguments:
- name: key
  type: key
- name: item
  type: string
categories:
- docs
- develop
- stack
- oss
- rs
- rc
- oss
- kubernetes
- clients
complexity: O(k), where k is the number of hash functions used by the last sub-filter
description: Checks whether an item exists in a Bloom Filter
group: bf
hidden: false
linkTitle: BF.EXISTS
module: Bloom
railroad_diagram: /images/railroad/bf.exists.svg
since: 1.0.0
stack_path: docs/data-types/probabilistic
summary: Checks whether an item exists in a Bloom Filter
syntax_fmt: BF.EXISTS key item
title: BF.EXISTS
---
Determines whether a given item was added to a Bloom filter.

This command is similar to [`BF.MEXISTS`](/content/commands/bf.mexists.md), except that only one item can be checked.

## Required arguments

<details open><summary><code>key</code></summary>

is key name for a Bloom filter.

</details>

<details open><summary><code>item</code></summary>

is an item to check.
</details>

## Examples

{{% redis-cli %}}
redis> BF.ADD bf item1
(integer) 1
redis> BF.EXISTS bf item1
(integer) 1
redis> BF.EXISTS bf item2
(integer) 0
{{% /redis-cli %}}

## Redis Software and Redis Cloud compatibility

| Redis<br />Software | Redis<br />Cloud | <span style="min-width: 9em; display: table-cell">Notes</span> |
|:----------------------|:-----------------|:------|
| <span title="Supported">&#x2705; Supported</span><br /> | <span title="Supported">&#x2705; Flexible & Annual</span><br /><span title="Supported">&#x2705; Free & Fixed</nobr></span> |  |

## Return information

{{< multitabs id="bf-exists-return-info" 
    tab1="RESP2" 
    tab2="RESP3" >}}

One of the following:
* [Integer reply](/content/develop/reference/protocol-spec.md#integers), where a value of `1` means the item was probably already added to the filter. A value of `0` means the item was definitely not added, `key` does not exist, or `key` contains a value of the wrong type.
* [Simple error reply](/content/develop/reference/protocol-spec.md#simple-errors) if invalid arguments are passed.

-tab-sep-

One of the following:
* [Boolean reply](/content/develop/reference/protocol-spec.md#booleans), where a value of `true` means the item was probably already added to the filter. A value of `false` means the item was definitely not added, `key` does not exist, or `key` contains a value of the wrong type.
* [Simple error reply](/content/develop/reference/protocol-spec.md#simple-errors) if invalid arguments are passed.

{{< /multitabs >}}