jq Cheatsheet

Q: How do I pretty-print JSON?

Pipe JSON to jq: `cat file.json | jq '.'` or `curl api.example.com | jq '.'`. jq adds syntax coloring by default. Use `-c` for compact output (one line).

Q: How do I extract nested fields?

Use dot notation: `jq '.field.subfield'`. For array access: `jq '.[0].name'`. Use `jq '.[] | .name'` to extract a field from all array elements. Use `-r` for raw (unquoted) output.

jq is a lightweight command-line JSON processor, like sed/awk for JSON data. Supports filtering, mapping, transformation, and aggregation — essential for API debugging and data processing.

Updated: 2026-07-20·20 commands

Quick Start

bash
jq '.' data.json                 # Pretty-print
jq '.name' package.json          # Extract key
jq '.dependencies | keys' pkg.json  # List dependency names
jq '.[] | select(.age > 30)' users.json  # Filter array
jq -r '.version' package.json    # Raw output (no quotes)

Startup & Modes(20)

Command	Level	Example
`jq --help` Show jq help	Basic	`jq --help`
`jq '.' file.json` Pretty-print JSON (format + color)	Basic	`jq '.' data.json`
`jq '.key'` Extract value of a key	Basic	`jq '.name' package.json`
`jq '.a.b.c'` Extract nested key (chained access)	Basic	`jq '.dependencies.jquery' package.json`
`jq '.[]'` Iterate over array elements	Intermediate	`jq '.[]' array.json`
`jq '.[0]'` Get first array element	Basic	`jq '.[0]' array.json`
`jq '.[] \| .name'` Iterate array and extract each name	Intermediate	`curl -s https://api.github.com/repos/jqlang/jq \| jq '.owner \| {login, id}'`
`jq '. \| {key1, key2}'` Select fields to construct new object	Intermediate	`jq '{name, version}' package.json`
`jq 'select(.age > 30)'` Filter array by condition	Intermediate	`jq '.[] \| select(.age > 30)' users.json`
`jq -r` Raw output (no quotes)	Basic	`jq -r '.name' package.json`
`jq -c` Compact output (one JSON per line)	Basic	`jq -c '.[]' data.json`
`jq -f` Read jq filter from file	Intermediate	`jq -f my-filter.jq data.json`
`jq 'group_by(.key)'` Group by specified key	Expert	`jq 'group_by(.category)' data.json`
`jq 'sort_by(.key)'` Sort by key	Intermediate	`jq 'sort_by(.stars) \| reverse' repos.json`
`jq 'length'` Calculate array length	Basic	`jq 'length' array.json`
`jq 'keys'` List all object keys	Basic	`jq 'keys' package.json`
`jq map select` Apply mapping to each array element	Intermediate	`jq 'map(select(.version > "1.0"))' deps.json`
`jq -s` Read multiple JSON objects into array (slurp)	Intermediate	`jq -s '.' file1.json file2.json`
`jq -n` Use null input (test filters)	Intermediate	`jq -n '{a: 1, b: 2}'`
`jq 'add'` Sum array elements	Intermediate	`jq '[.[].price] \| add' items.json`

FAQ

How do I pretty-print JSON?

How do I extract nested fields?

This cheatsheet is compiled from official tool documentation. Last updated: 2026-07-20.