jq

Command-line JSON processor for extracting, filtering, and transforming JSON.

Installation

**macOS / Linux (Homebrew):**

```bash

brew install jq

```

**All platforms:** See [jqlang.org/download](https://jqlang.org/download/) for packages, binaries, and build instructions.

```bash

jq '[filter]' [file.json]

cat file.json | jq '[filter]'

```

```bash

.key # Get key

.a.b.c # Nested access

.[0] # First element

.[] # Iterate array

.[] | select(.x > 5) # Filter

{a: .x, b: .y} # Reshape

. + {new: "val"} # Add field

del(.key) # Remove field

length # Count

[.[] | .x] | add # Sum

keys # List keys

unique # Dedupe array

group_by(.x) # Group

```

`-r` raw output (no quotes) · `-c` compact · `-s` slurp into array · `-S` sort keys

```bash

jq '.users[].email' data.json # Extract emails

jq -r '.name // "default"' data.json # With fallback

jq '.[] | select(.active)' data.json # Filter active

jq -s 'add' *.json # Merge files

jq '.' file.json # Pretty-print

```