---
acl_categories:
- '@keyspace'
- '@read'
- '@slow'
arguments:
- display_text: key
  key_spec_index: 0
  name: key
  type: key
arity: 3
categories:
- docs
- develop
- stack
- oss
- rs
- rc
- oss
- kubernetes
- clients
command_flags:
- readonly
complexity: O(1)
description: Returns the internal encoding of a Redis object.
group: generic
hidden: false
hints:
- nondeterministic_output
key_specs:
- RO: true
  begin_search:
    spec:
      index: 2
    type: index
  find_keys:
    spec:
      keystep: 1
      lastkey: 0
      limit: 0
    type: range
linkTitle: OBJECT ENCODING
railroad_diagram: /images/railroad/object-encoding.svg
since: 2.2.3
summary: Returns the internal encoding of a Redis object.
syntax_fmt: OBJECT ENCODING key
title: OBJECT ENCODING
---
Returns the internal encoding for the Redis object stored at `<key>`

Redis objects can be encoded in different ways:

* Strings can be encoded as: 

    - `raw`, normal string encoding.
    - `int`, strings representing integers in a 64-bit signed interval, encoded in this way to save space.
    - `embstr`, an embedded string, which is an object where the internal simple dynamic string, `sds`, is an unmodifiable string allocated in the same chuck as the object itself.
      `embstr` can be strings with lengths up to the hardcoded limit of `OBJ_ENCODING_EMBSTR_SIZE_LIMIT` or 44 bytes. 

* Lists can be encoded as:
 
    - `linkedlist`, simple list encoding. No longer used, an old list encoding.
    - `ziplist`, Redis <= 6.2, a space-efficient encoding used for small lists.
    - `listpack`, Redis >= 7.0, a space-efficient encoding used for small lists.
    - `quicklist`, encoded as linkedlist of ziplists or listpacks.

* Sets can be encoded as:

    - `hashtable`, normal set encoding.
    - `intset`, a special encoding used for small sets composed solely of integers.
    - `listpack`, Redis >= 7.2, a space-efficient encoding used for small sets.

* Hashes can be encoded as:

    - `zipmap`, no longer used, an old hash encoding.
    - `hashtable`, normal hash encoding.
    - `ziplist`, Redis <= 6.2, a space-efficient encoding used for small hashes.
    - `listpack`, Redis >= 7.0, a space-efficient encoding used for small hashes.

* Sorted Sets can be encoded as:

    - `skiplist`, normal sorted set encoding.
    - `ziplist`, Redis <= 6.2, a space-efficient encoding used for small sorted sets.
    - `listpack`, Redis >= 7.0, a space-efficient encoding used for small sorted sets.

* Streams can be encoded as:

  - `stream`, encoded as a radix tree of listpacks.

All the specially encoded types are automatically converted to the general type once you perform an operation that makes it impossible for Redis to retain the space saving encoding.

## 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; Standard</span><br /><span title="Not supported"><nobr>&#x274c; Active-Active</nobr></span> | <span title="Supported">&#x2705; Standard</span><br /><span title="Not supported"><nobr>&#x274c; Active-Active</nobr></span> | For Active-Active databases, use `CRDT.DEBUG ENCODING` instead. |

## Return information

{{< multitabs id="object-encoding-return-info" 
    tab1="RESP2" 
    tab2="RESP3" >}}

One of the following:
* [Nil reply](../../develop/reference/protocol-spec#bulk-strings): if the key doesn't exist.
* [Bulk string reply](../../develop/reference/protocol-spec#bulk-strings): the encoding of the object.

-tab-sep-

One of the following:
* [Null reply](../../develop/reference/protocol-spec#nulls): if the key doesn't exist.
* [Bulk string reply](../../develop/reference/protocol-spec#bulk-strings): the encoding of the object.

{{< /multitabs >}}