# BF.INFO

> Show a Bloom filter's capacity, size, layers, item count and expansion rate.

URL: https://docs.hotkv.com/commands/bf-info/

```
BF.INFO key [CAPACITY | SIZE | FILTERS | ITEMS | EXPANSION]
```

- Group: Bloom filter
- Complexity: O(1)
- HotKV Cloud: all plans
- On-Premise: no license needed

`BF.INFO` describes the Bloom filter at `key`. Pass one field name to get only
that value.

## Fields

| Field | Option | Meaning |
| --- | --- | --- |
| `Capacity` | `CAPACITY` | Items the filter is sized for, across all its layers. |
| `Size` | `SIZE` | Memory taken by the filter, in bytes. |
| `Number of filters` | `FILTERS` | Layers: 1, plus one for each time a scaling filter grew. |
| `Number of items inserted` | `ITEMS` | Items added (as [BF.CARD](https://docs.hotkv.com/commands/bf-card/index.md) reports). |
| `Expansion rate` | `EXPANSION` | The growth factor, or nil for a non-scaling filter. |

Option names are case-insensitive.

## Return value

| Case | RESP2 | RESP3 |
| --- | --- | --- |
| All fields | Flat array of field names and values | Map |
| One field | Array with the one value | Map with the one field |

Error replies: `ERR not found` when the key does not exist,
`Invalid information value` for an unknown field, and `WRONGTYPE`.

## Examples

```
127.0.0.1:6379> BF.RESERVE signups 0.01 1000
OK
127.0.0.1:6379> BF.ADD signups alice
(integer) 1
127.0.0.1:6379> BF.INFO signups
 1) Capacity
 2) (integer) 1000
 3) Size
 4) (integer) 1480
 5) Number of filters
 6) (integer) 1
 7) Number of items inserted
 8) (integer) 1
 9) Expansion rate
10) (integer) 2
127.0.0.1:6379> BF.INFO signups ITEMS
1) (integer) 1
```

## Compatibility

Same fields and values as `BF.INFO` in RedisBloom: a filter created with the
same settings reports the same capacity and size.

## See also

[BF.CARD](https://docs.hotkv.com/commands/bf-card/index.md), [BF.RESERVE](https://docs.hotkv.com/commands/bf-reserve/index.md)