Redis Cheat Sheet

The Redis cheat sheet includes basic syntax and methods to help you use Redis. Redis is an open-source (BSD licensed), in-memory data structure store used as a database, cache, message broker, and streaming engine. Redis provides data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs, geospatial indexes, and streams.

Redis has built-in replication, Lua scripting, LRU eviction, transactions, and different levels of on-disk persistence, and provides high availability via Redis Sentinel and automatic partitioning with Redis Cluster.

String

Redis strings store sequences of bytes, including text, serialized objects, and binary arrays. As such, strings are the simplest type of value you can associate with a Redis key. They’re often used for caching, but they support additional functionality that lets you implement counters and perform bitwise operations, too.

APPEND	Append
BITCOUNT	Count set bits
BITOP	Bitwise operations
BITPOS	Find the first set of bit
DECR	Decrement integer
DECRBY	Subtract from integer
GET	Get by key
GETBIT	Get bit by index
GETRANGE	Get substring
GETSET	Set, returning the old value
INCR	Increment integer
INCRBY	Add to integer
INCRBYFLOAT	Add to float
MGET	Get multiple
MSET	Set multiple
MSETNX	Set multiple if don’t exist
PSETEX	Set with expiry (ms)
SET	Set
SETBIT	Set bit by index
SETEX	Set with expiry (seconds)
SETNX	Set if doesn’t exist
SETRANGE	Set substring
STRLEN	Get length
Strings can be used as numbers, arrays, bit sets, and binary data

Lists

Redis lists are implemented via Linked Lists. This means that even if you have millions of elements inside a list, the operation of adding a new element in the head or in the tail of the list is performed in constant time.

BLPOP	Blocking left pop
BRPOP	Blocking right pop
BRPOPLPUSH	Blocking rotate
LINDEX	Access by index
LINSERT	Insert next to
LLEN	Get length
LPOP	Pop from start
LPUSH	Push onto start
LPUSHX	Push if the list exists
LRANGE	Access Range
LREM	Remove
LSET	Set item by index
LTRIM	Remove start and/or end items
RPOP	Pop from end
RPOPLPUSH	Rotate
RPUSH	Push onto end
RPUSHX	Push onto the end if a list exists

Hashes

Redis hashes are record types structured as collections of field-value pairs. You can use hashes to represent basic objects and to store groupings of counters, among other things.

HDEL	Delete item
HEXISTS	Check for item
HGET	Get item
HGETALL	Return all items
HINCRBY	Add to the integer value
HINCRBYFLOAT	Add to float value
HKEYS	Return all keys
HLEN	Get the number of items
HMGET	Get multiple items
HMSET	Set multiple items
HSCAN	Iterate items
HSET	Set item
HSETNX	Set item if doesn’t exist
HVALS	Return all values

Sets

A Redis set is an unordered collection of unique strings (members). You can use Redis sets to efficiently:

• Track unique items (e.g., track all unique IP addresses accessing a given blog post).
• Represent relations (e.g., the set of all users with a given role).
• Perform common set operations such as intersection, unions, and differences.

SADD	Add item
SCARD	Get size
SDIFF	Get difference
SDIFFSTORE	Store difference
SINTER	Inters­ection
SINTERSTORE	Store inters­ection
SISMEMBER	Check for item
SMEMBERS	Get all
SMOVE	Move item to another set
SPOP	Pop random item
SRANDMEMBER	Get random item
SREM	Remove matching
SSCAN	Iterate items
SUNION	Union
SUNIONSTORE	Store union

Sorted sets

A Redis sorted set is a collection of unique strings (members) ordered by an associated score. When more than one string has the same score, the strings are ordered lexicographically. Some use cases for sorted sets include:

ZADD	Add item
ZCARD	Get number of items
ZCOUNT	Number of items within score range
ZINCRBY	Add to score
ZINTERSTORE	Store inters­ection
ZLEXCOUNT	Lexico­gra­phical range count
ZRANGE	Get items within rank range
ZLEXRANGE	Get items within lexico­gra­phical range
ZRANGEBYSCORE	Get items within score range
ZRANK	Get item rank
ZREM	Remove item(s)
ZREMRANGEBYLEX	Remove items within lexico­gra­phical range
ZREMRANGEBYRANK	Remove items within rank range
ZREMRANGEBYSCORE	Remove items within score range
ZREVRANGE	ZRANGE in reverse order
ZREVRANGEBYSCORE	ZRANGE­BYSCORE in reverse order
ZREVRANK	ZRANK in reverse order
ZSCAN	Iterate items
ZSCORE	Get item score
ZUNIONSTORE	Store union
Lexico­gra­phical commands require all items to have the same score

Redis Streams

A Redis stream is a data structure that acts like an append-only log but also implements several operations to overcome some of the limits of a typical append-only log. These include random access in O(1) time and complex consumption strategies, such as consumer groups. You can use streams to record and simultaneously syndicate events in real time.

XADD	Adds a new entry to a stream.
XREAD	Reads one or more entries, starting at a given position and moving forward in time.
XRANGE	Returns a range of entries between two supplied entry IDs.
XLEN	Returns the length of a stream.

Redis Geospatial

Redis geospatial indexes let you store coordinates and search for them. This data structure is useful for finding nearby points within a given radius or bounding box.

GEOADD	Adds a location to a given geospatial index (note that longitude comes before latitude with this command).
GEOSEARCH	Returns locations with a given radius or a bounding box.

Redis Bitmaps

Bitmaps are not an actual data type, but a set of bit-oriented operations defined on the String type which is treated like a bit vector. Since strings are binary safe blobs and their maximum length is 512 MB, they are suitable to set up to 2^32 different bits.

SETBIT	Sets a bit at the provided offset to 0 or 1.
GETBIT	Returns the value of a bit at a given offset.
BITOP	Lets you perform bitwise operations against one or more strings.

Redis Bitfields

Redis bitfields let you set, increment, and get integer values of arbitrary bit length. For example, you can operate on anything from unsigned 1-bit integers to signed 63-bit integers. These values are stored using binary-encoded Redis strings. Bitfields support atomic read, write and increment operations, making them a good choice for managing counters and similar numerical values.

BITFIELD	Atomically sets, increments and reads one or more values.
BITFIELD_RO	A read-only variant of BITFIELD

Database

DEL	Delete item
DUMP	Serialise item
EXISTS	Check for key
EXPIRE	Set a timeout on item
EXPIREAT	Set timeout by timestamp
KEYS	Get all keys to match the pattern
MIGRATE	Transfer an item between Redis instances
MOVE	Transfer an item between databases
OBJECT	Inspect item
PERSIST	Remove timeout
PEXPIRE	Set timeout (ms)
PEXPIREAT	Set timeout (ms timestamp)
PTTL	Get item time to live (ms)
RANDOMKEY	Get random key
RENAME	Change item’s key
RENAMENX	Change item’s key if new key doesn’t exist
RESTORE	Deseri­alise
SCAN	Iterate keys
SORT	Get or store sorted copy of list, set or sorted set
TTL	Get item time to live
TYPE	Get type of item

Client­/Server

AUTH	Request authen­tic­ation
ECHO	Return message
PING	Test connection
QUIT	Close connection
SELECT	Set current database by index

Scripts

EVAL	Run
EVALSHA	Run cached
SCRIPT EXISTS	Check by hash
SCRIPT FLUSH	Clear cache
SCRIPT KILL	Kill running script
SCRIPT LOAD	Add to cache
Lua scripts access keys through the array KEYS and additional arguments through the array ARGV.

HyperL­ogLogs

PFADD	Add items
PFCOUNT	Get approx­imate size
PFMERGE	Merge HyperL­ogLogs

Redis Cheat Sheet