Using jq or alternative command line tools to compare JSON files

If your shell supports process substitution (Bash-style follows, see docs):

diff <(jq --sort-keys . A.json) <(jq --sort-keys . B.json)

Objects key order will be ignored, but array order will still matter. It is possible to work-around that, if desired, by sorting array values in some other way, or making them set-like (e.g. ["foo", "bar"] → {"foo": null, "bar": null}; this will also remove duplicates).

Alternatively, substitute diff for some other comparator, e.g. cmp, colordiff, or vimdiff, depending on your needs. If all you want is a yes or no answer, consider using cmp and passing --compact-output to jq to not format the output for a potential small performance increase.

Use jd with the -set option:

No output means no difference.

$ jd -set A.json B.json

Differences are shown as an @ path and + or -.

$ jd -set A.json C.json@ ["People",{}]+ "Carla"

The output diffs can also be used as patch files with the -p option.

$ jd -set -o patch A.json C.json; jd -set -p patch B.json{"City":"Boston","People":["John","Carla","Bryan"],"State":"MA"}

https://github.com/josephburnett/jd#command-line-usage

Since jq's comparison already compares objects without taking into account key ordering, all that's left is to sort all lists inside the object before comparing them. Assuming your two files are named a.json and b.json, on the latest jq nightly:

jq --argfile a a.json --argfile b b.json -n '($a | (.. | arrays) |= sort) as $a | ($b | (.. | arrays) |= sort) as $b | $a == $b'

This program should return "true" or "false" depending on whether or not the objects are equal using the definition of equality you ask for.

EDIT: The (.. | arrays) |= sort construct doesn't actually work as expected on some edge cases. This GitHub issue explains why and provides some alternatives, such as:

def post_recurse(f): def r: (f | select(. != null) | r), .; r; def post_recurse: post_recurse(.[]?); (post_recurse | arrays) |= sort

Applied to the jq invocation above:

jq --argfile a a.json --argfile b b.json -n 'def post_recurse(f): def r: (f | select(. != null) | r), .; r; def post_recurse: post_recurse(.[]?); ($a | (post_recurse | arrays) |= sort) as $a | ($b | (post_recurse | arrays) |= sort) as $b | $a == $b'