How to format JSON file in Vim

Question

Given a file with a large JSON object all on one line like

{"versions":[{"count":2,"version":""},{"count":1,"version":"1.1.1"},{"count":14,"version":"2.9"},{...

How can I format this to be human readable in Vim?

Related StackOverflow Post: How to fix JSON indentation in vim? — Peter Rincker, Jul 30 '18 at 15:37

score 239 · Accepted Answer · edited Apr 06 '20 at 03:01

239

Or you can install jq which is faster (written in C) from your package manager (e.g. sudo apt install jq in Ubuntu/Debian, sudo dnf install jq on Fedora/RHEL/CentOS) or from source and then in vim, type:

:%!jq .

edited Apr 06 '20 at 03:01

filbranden

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answered May 14 '19 at 07:59

SebMa

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1

:%!jq works just as well for me. – Micks Ketches Dec 27 '19 at 22:38
5

Hm... only works with the added . for me. I wonder why. – Costa Michailidis Apr 15 '20 at 23:02
1

on MacOS, I need the . as well – Thomas Jun 14 '20 at 18:53
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Don't need to install jq on Ubuntu/Debian 14+ onward. – logbasex Nov 26 '20 at 06:33
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On MacOS after installing jq with brew install jq I could also just type :%!jq without a dot at the end – olik79 Apr 20 '21 at 19:01
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Sometimes, when I search for how to do something inside vim, I find theses answers that reminds me that one of the reasons I love vim is because it works seamlessly with all command line tools we already have. – Alex Oliveira Jun 21 '21 at 19:40
@logbasex I have to on Ubuntu 20 – Rémy Hosseinkhan Boucher Jul 07 '22 at 22:19
i have malformed json file unfortunately and seems running the above command just puts the error output from jq into the current buffer. – ipatch Feb 05 '23 at 18:13
1

Would love to see an explanation on the syntax of this command (well, I do know jq as a command line tool) and how it's being used by vim in this particular case. – Alexandre Apr 11 '23 at 18:32
2

@Alexandre % stands for a range equal to 1,$ (the entire file) and ! filters the range of line to the external program jq. – SebMa Apr 11 '23 at 21:11
For those stuck on Windows, you can install jq as a chocolatey package – Michael Dandini Jun 20 '23 at 19:25
1

@Thomas, @logbasex, @RémyHosseinkhanBoucher, the . is the identity filter, meaning "give me back exactly what I gave you." Without a filter, some versions or invocations of jq will not assume which part of the JSON you want it to process, so it's best to always include the dot. See man jq. Use :%!jq . --tab to get indentation with tabs. – Walf Feb 15 '24 at 01:19

score 96 · Answer 2 · answered Jul 28 '18 at 11:49

96

This one-liner works well to format JSON in Vim into a human readable form:

:%!python -m json.tool

answered Jul 28 '18 at 11:49

ljs.dev

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Do you memorize that and type it every time or do you use some kind of alias? – asedsami Dec 13 '19 at 17:05
I tend to use the :%!jq . answer these days, as I do less with Python and tend to have jq installed on my systems for any JSON work in CLI. I also get notifications for this SO question quite often, so it helps me not to forget :P I prefer vim with minimal customization, no plugins, etc, which is another reason the jq solution is now my preferred. – ljs.dev Dec 14 '19 at 07:37
(updated accepted answer to reflect this) – ljs.dev Dec 14 '19 at 07:37
8

Just a warning that this will escape some characters into ASCII only. So if you want UTF8 encoding jq is the better option. – AndrewHarvey Feb 05 '20 at 03:01
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Python 3.9 has introduced the option --no-ensure-ascii. – Hotschke May 27 '21 at 06:55
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Useful if you are on a cloud environment and don't have permissions to install jq – Anurag A S Jul 20 '22 at 15:11

score 11 · Answer 3 · edited Nov 19 '19 at 15:25

11

To format in a deterministic way, we need to sort the hash. None of the other answers did that for me, so I created my own:

function! FormatJson()
python << EOF
import vim
import json
try:
    buf = vim.current.buffer
    json_content = '\n'.join(buf[:])
    content = json.loads(json_content)
    sorted_content = json.dumps(content, indent=4, sort_keys=True)
    buf[:] = sorted_content.split('\n')
except Exception, e:
    print e
EOF
endfunction

Usage:

:call FormatJson()

edited Nov 19 '19 at 15:25

D. Ben Knoble

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answered Nov 19 '19 at 15:09

Prajit Patil

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Welcome to [vi.se]! Nice first answer; it's interesting that you consider the sorting aspect! – D. Ben Knoble Nov 19 '19 at 15:26
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About the sorting I'm pretty sure jq mentionned in SebMa answers has a --sort-keys option which would do the job. But it's cool to write your own implementation too :) – statox Nov 19 '19 at 16:23

score 5 · Answer 4 · answered Mar 10 '20 at 09:44

I use this :Jsonf command. It's can format unicode.

command! Jsonf :execute '%!python -c "import json,sys,collections,re; sys.stdout.write(re.sub(r\"\\\u[0-9a-f]{4}\", lambda m:m.group().decode(\"unicode_escape\").encode(\"utf-8\"),json.dumps(json.load(sys.stdin, object_pairs_hook=collections.OrderedDict), indent=2)))"'

score 1 · Answer 5 · answered Oct 01 '19 at 23:22

1

If PHP is available, add the tool jf as a JSON Formatter by Composer:

$ composer global require codegear/json-formatter

Then Format current file:

:%!jf %

Or add a keymap in vimrc:

nnoremap <Leader>jf :%!jf %<CR>

answered Oct 01 '19 at 23:22

Lei Fan

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ka3ak · Answer 6 · 2021-01-17T20:20:50.387

0

If nodejs and xargs are available on your system you can add the following command to your .vimrc

command! -range FormatJson <line1>,<line2>!xargs -0 -I {} node -e 'console.log(JSON.stringify({}, null, 2));'

After that you can visual select the JSON text in the buffer and run

:'<,'>FormatJson

to pretty print it. Works with Unicode too.

edited Jan 17 '21 at 20:20

answered Jan 17 '21 at 19:18

ka3ak

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score 0 · Answer 7 · answered Mar 08 '21 at 18:54

0

Another solution is to use coc-format-json.

answered Mar 08 '21 at 18:54

dessalines

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Welcome to [vi.se]! This answer would benefit from further explanation via [edit]. – D. Ben Knoble Mar 09 '21 at 14:42

score 0 · Answer 8 · edited May 03 '21 at 10:14

0

I wanted to open jq with vim. However i didn't manage to find a way to do it in one command.

I wrote a shell script, and it worked for me (linux version : redhat 7.6):

# Don't miss the dot after jq
cat input.json | jq . > output.json
vim output.json

edited May 03 '21 at 10:14

statox

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answered May 03 '21 at 07:18

jonatan ganpul

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You can use - to read from stdin: jq input.json . | vim - (maybe you need to reverse the input.json and . in that jq command). Another option would be to use -c or + to run a command when Vim opens: vim +':%!jq .' input.json – Martin Tournoij May 03 '21 at 07:41

Konstantin Glukhov · Answer 9 · 2022-09-20T08:14:54.667

Use ALE to help you with linting/formatting

Install ALE into .vim/vimfiles/pack/*/opt/ale
add the following line to your vimrc:

packadd ale

create .vim/vimfiles/after/ftplugin/json.vim

if exists("b:my_ftplugin") | finish | endif
let b:my_ftplugin = 1
if !exists('g:loaded_ale') | finish | endif
" Pick from available fixers :help ale-fix
" E.g., use prettier if it is installed:
let b:ale_fixers = ['prettier']

If no fixers are available at your disposal, python is always an option:

if !executable('python') | finish | endif
let b:ale_fixers = [{ -> {'command': 'python -m json.tool --indent 2 -'}}]

Run the following command to reformat the current vim buffer:

:ALEFix

score 0 · Answer 10 · answered Feb 17 '23 at 08:28

Only usable for one (or few) files.

Set all values at a new line with substitute commands (they must fit your file!):

:%s/","/",\r"/g
:%s/null,"/null,\r"/g
:%s/(\d),"/\1,\r"/g
... (there are },{, [{

{
"versions":[
{
"count":2,"version":""
},
{"count":1,
"version":"1.1.1"
},
{
"count":14,
"version":"2.9"
}]
}

Then go to the first { and type =%.

The JSON will be rudimentary formatted. Not perfect but readable.

How to format JSON file in Vim

10 Answers10

Only usable for one (or few) files.