JSON

Redis JSON provides native JSON document storage with atomic operations, JSONPath queries, and efficient updates. It’s part of the Redis modules and requires compilation with BUILD_WITH_MODULES=yes.

JSON support requires building Redis with BUILD_WITH_MODULES=yes. See the installation guide for details.

Use Cases

Document database: Store and query JSON documents
User profiles: Complex nested user data
Product catalogs: Rich product information
Configuration storage: Application settings
API caching: Cache JSON API responses
Event data: Structured event payloads

Key Commands

Basic Operations

# Set JSON document
redis> JSON.SET user:1001 $ '{"name":"Alice","email":"[email protected]","age":30}'
OK

# Get entire document
redis> JSON.GET user:1001
"{\"name\":\"Alice\",\"email\":\"[email protected]\",\"age\":30}"

# Get specific field
redis> JSON.GET user:1001 $.name
"[\"Alice\"]"

# Get multiple paths
redis> JSON.GET user:1001 $.name $.email
"{\"$.name\":[\"Alice\"],\"$.email\":[\"[email protected]\"]}"

# Delete document
redis> JSON.DEL user:1001
(integer) 1

Path Operations

# Set nested value
redis> JSON.SET user:1001 $ '{"name":"Alice","address":{"city":"NYC"}}'
OK

# Update nested field
redis> JSON.SET user:1001 $.address.zip "10001"
OK

# Get nested value
redis> JSON.GET user:1001 $.address.city
"[\"NYC\"]"

# Delete path
redis> JSON.DEL user:1001 $.address.zip
(integer) 1

Array Operations

# Set document with array
redis> JSON.SET user:1001 $ '{"name":"Alice","tags":["developer","redis"]}'
OK

# Append to array
redis> JSON.ARRAPPEND user:1001 $.tags '"python"'
[3]

# Insert into array
redis> JSON.ARRINSERT user:1001 $.tags 0 '"senior"'
[4]

# Get array length
redis> JSON.ARRLEN user:1001 $.tags
[4]

# Pop from array
redis> JSON.ARRPOP user:1001 $.tags -1
"\"python\""

# Trim array
redis> JSON.ARRTRIM user:1001 $.tags 0 1
[2]

Numeric Operations

# Set numeric field
redis> JSON.SET stats $ '{"views":100,"likes":25}'
OK

# Increment
redis> JSON.NUMINCRBY stats $.views 1
"[101]"

# Multiply
redis> JSON.NUMMULTBY stats $.likes 2
"[50]"

String Operations

# Append to string
redis> JSON.SET user:1001 $ '{"name":"Alice"}'
OK
redis> JSON.STRAPPEND user:1001 $.name '" Smith"'
[11]

# Get string length
redis> JSON.STRLEN user:1001 $.name
[11]

JSONPath Syntax

Redis JSON supports JSONPath for querying:

$: Root
.key: Child member
[index]: Array index
[*]: All array elements
..key: Recursive descent
[?(@.key > value)]: Filter expressions

# Complex document
redis> JSON.SET products $ '[
  {"id":1,"name":"Redis Book","price":29.99,"inStock":true},
  {"id":2,"name":"JSON Guide","price":19.99,"inStock":false}
]'
OK

# Get all names
redis> JSON.GET products $[*].name
"[\"Redis Book\",\"JSON Guide\"]"

# Get in-stock products
redis> JSON.GET products $[?(@.inStock==true)]
"[{\"id\":1,\"name\":\"Redis Book\",\"price\":29.99,\"inStock\":true}]"

Time Complexity

Command	Time Complexity	Description
JSON.SET	O(M+N)	M=path, N=value size
JSON.GET	O(M+N)	M=path, N=result size
JSON.DEL	O(N)	N=keys deleted
JSON.ARRAPPEND	O(1)	Append to array
JSON.ARRINSERT	O(N)	N=array size
JSON.ARRLEN	O(1)	Get array length
JSON.NUMINCRBY	O(1)	Increment number
JSON.STRLEN	O(1)	Get string length

Patterns and Examples

User Profile

# Create profile
redis> JSON.SET profile:alice $ '{
  "username": "alice",
  "email": "[email protected]",
  "preferences": {
    "theme": "dark",
    "notifications": true
  },
  "tags": ["developer", "redis"],
  "stats": {
    "posts": 42,
    "followers": 156
  }
}'
OK

# Update preference
redis> JSON.SET profile:alice $.preferences.theme '"light"'
OK

# Add tag
redis> JSON.ARRAPPEND profile:alice $.tags '"python"'
[3]

# Increment post count
redis> JSON.NUMINCRBY profile:alice $.stats.posts 1
"[43]"

# Get specific fields
redis> JSON.GET profile:alice $.username $.stats.posts
"{\"$.username\":[\"alice\"],\"$.stats.posts\":[43]}"

Product Catalog

# Add product
redis> JSON.SET product:2001 $ '{
  "id": 2001,
  "name": "Redis Book",
  "description": "Comprehensive Redis guide",
  "price": 29.99,
  "stock": 150,
  "categories": ["books", "database", "redis"],
  "metadata": {
    "author": "John Doe",
    "pages": 350,
    "isbn": "123-456-789"
  },
  "reviews": []
}'
OK

# Update stock
redis> JSON.NUMINCRBY product:2001 $.stock -1
"[149]"

# Add review
redis> JSON.ARRAPPEND product:2001 $.reviews '{
  "user": "alice",
  "rating": 5,
  "comment": "Excellent!"
}'
[1]

# Update price
redis> JSON.SET product:2001 $.price 24.99
OK

API Response Caching

# Cache API response
redis> JSON.SET cache:api:/users/123 $ '{
  "data": {
    "id": 123,
    "name": "Alice",
    "email": "[email protected]"
  },
  "meta": {
    "cached_at": 1709467200,
    "ttl": 3600
  }
}'
OK

# Set expiration
redis> EXPIRE cache:api:/users/123 3600
(integer) 1

# Get cached data
redis> JSON.GET cache:api:/users/123 $.data

Configuration Management

# Store app config
redis> JSON.SET config:app $ '{
  "database": {
    "host": "localhost",
    "port": 5432,
    "pool_size": 10
  },
  "cache": {
    "enabled": true,
    "ttl": 3600
  },
  "features": {
    "beta_features": ["feature1", "feature2"]
  }
}'
OK

# Update config value
redis> JSON.SET config:app $.cache.ttl 7200
OK

# Toggle feature
redis> JSON.SET config:app $.cache.enabled false
OK

# Get config section
redis> JSON.GET config:app $.database

JSON vs String

Operation	JSON Module	String (serialized JSON)
Update field	Direct path update	Deserialize, update, serialize
Query nested	JSONPath	Deserialize entire object
Atomicity	Atomic operations	Manual locking
Performance	Faster for updates	Faster for full reads
Memory	Optimized	Standard

Best Practices

Use JSONPath for efficient nested updates
Set expiration on cached documents
Keep documents focused - avoid very large documents
Index with RediSearch for complex queries
Use atomic operations instead of get-modify-set

For complex queries across multiple documents, combine Redis JSON with RediSearch to create indexes and perform full-text search, aggregations, and filtering.

Very large JSON documents (over 1MB) can impact performance. Consider splitting into multiple keys or using compression.

Integration with RediSearch

Combine JSON with RediSearch for powerful querying:

# Create index on JSON documents
redis> FT.CREATE idx:users ON JSON PREFIX 1 user: SCHEMA 
  $.name AS name TEXT 
  $.email AS email TAG 
  $.age AS age NUMERIC

# Search users
redis> FT.SEARCH idx:users "@age:[25 35]" RETURN 3 $.name $.email $.age

Get Started

Core Concepts

Data Types

Advanced Features

Operations

Client Libraries

Use Cases

Key Commands

Basic Operations

Path Operations

Array Operations

Numeric Operations

String Operations

JSONPath Syntax

Time Complexity

Patterns and Examples

User Profile

Product Catalog

API Response Caching

Configuration Management

JSON vs String

Best Practices

Integration with RediSearch

Next Steps

Query Engine

Hashes

Build docs developers (and LLMs) love

Get Started

Core Concepts

Data Types

Advanced Features

Operations

Client Libraries

​Use Cases

​Key Commands

​Basic Operations

​Path Operations

​Array Operations

​Numeric Operations

​String Operations

​JSONPath Syntax

​Time Complexity

​Patterns and Examples

​User Profile

​Product Catalog

​API Response Caching

​Configuration Management

​JSON vs String

​Best Practices

​Integration with RediSearch

​Next Steps

Query Engine

Hashes

Build docs developers (and LLMs) love

Use Cases

Key Commands

Basic Operations

Path Operations

Array Operations

Numeric Operations

String Operations

JSONPath Syntax

Time Complexity

Patterns and Examples

User Profile

Product Catalog

API Response Caching

Configuration Management

JSON vs String

Best Practices

Integration with RediSearch

Next Steps