jq Examples — Practical jq Query Snippets

.servers[] | select(.role == "backend") | .ip

Use jq select() to filter an array of JSON objects by an attribute value. Interactive example that keeps only objects whose field matches a given value.

.countries | sort_by(.population) | reverse | .[] | .name

Sort a JSON array by a field using jq sort_by(). Interactive example showing how to sort objects ascending, then reverse for descending order.

.calls | group_by(.route) | map({key: .[0].route, value: map(.path)})

Group an array of JSON objects by a field with jq group_by(). Interactive example that buckets records by a shared key and collects their values.

.calls | group_by(.route) | map({key: .[0].route, value: map(.callTimeMs) | length})

Count items per group in jq by combining group_by() with length. Interactive example that counts how many records fall into each group.

.calls | group_by(.route) | map({key: .[0].route, value: map(.callTimeMs) | add})

Sum a numeric field per group in jq by combining group_by() with add. Interactive example that totals values within each group.

to_entries

Convert a JSON object into an array of {key, value} pairs with jq to_entries. Interactive example for iterating over objects with dynamic keys.

.countries[] | [{key:.name, value: {id, population}}] | from_entries

Build a JSON object from an array of {key, value} pairs with jq from_entries. Interactive example that rebuilds an object keyed by a chosen field.

with_entries(.key |= ("0"+.))

Transform every key or value of a JSON object with jq with_entries. Interactive example that rewrites object keys in a single pass.

.countries | map({name, id, people: .population})

Transform each element of a JSON array with jq map(). Interactive example that reshapes and renames fields for every object in an array.

map_values({name, ageYears: .age})

Transform every value of a JSON object with jq map_values(). Interactive example that reshapes each value while preserving the object keys.

def isLocalhost: . == "127.0.0.1";

.hosts[] | {localhost: .host | isLocalhost}

Define reusable helper functions in jq with def. Interactive example showing how to declare a function and apply it inside a pipeline.

def areaFromCountry: if . == "USA" then "North America"
  elif . == "Germany" then "Europe"
  elif . == "Japan" then "Asia"
  else "Unknown"
  end;

.countries[] | {area: .name | areaFromCountry}

Branch on values in jq with if / elif / else / end. Interactive example that maps input values to different results using conditional logic.