46

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?

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75

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 .
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  • 1
    :%!jq works just as well for me. – Micks Ketches Dec 27 '19 at 22:38
  • 4
    Hm... only works with the added . for me. I wonder why. – Costa Apr 15 '20 at 23:02
  • 1
    on MacOS, I need the . as well – Thomas Jun 14 '20 at 18:53
  • Don't need to install jq on Ubuntu/Debian 14+ onward. – logbasex Nov 26 '20 at 6:33
43

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

:%!python -m json.tool

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  • 1
    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 7:37
  • (updated accepted answer to reflect this) – ljs.dev Dec 14 '19 at 7:37
  • 4
    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 5 '20 at 3:01
6

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()
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  • Welcome to Vi and Vim! Nice first answer; it's interesting that you consider the sorting aspect! – D. Ben Knoble♦ Nov 19 '19 at 15:26
  • 1
    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
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>
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1

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)))"'
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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.

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