Best way to format large JSON file? (~30 mb)

Question

I need to format a large JSON file for readability, but every resource I've found (mostly online) doesn't deal with data say, above 1-2 MB. I need to format about 30 MB. Is there any way to do this, or any way to code something to do this?

Answer 1

With python >= 2.6 you can do the following:

For Mac/Linux users:

cat ugly.json | python -mjson.tool > pretty.json

For Windows users (thanks to the comment from dnk.nitro):

type ugly.json | python -mjson.tool > pretty.json

Answer 2

jq can format or beautify a ~100MB JSON file in a few seconds:

jq '.' myLargeUnformattedFile.json > myLargeBeautifiedFile.json

The command above will beautify a single-line ~120MB file in ~10 seconds, and jq gives you a lot of json manipulation capabilities beyond simple formatting, see their tutorials.

Answer 3

jsonpps is the only one worked for me (https://github.com/bazaarvoice/jsonpps).
It doesn't load everything to RAM unlike jq, jsonpp and others that I tried.

Some useful tips regarding installation and usage:

Download url: https://repo1.maven.org/maven2/com/bazaarvoice/jsonpps/jsonpps/1.1/jsonpps-1.1.jar

Shortcut (for Windows):

1. Create file jsonpps.cmd in the same directory with the following content:
   @echo off java -Xms64m -Xmx64m -jar %~dp0\jsonpps-1.1.jar %*

Shortcut usage examples:

1. Format stdin to stdout:
   echo { "x": 1 } | jsonpps
2. Format stdin to file
   echo { "x": 1 } | jsonpps -o output.json
3. Format file to file:
   jsonpps input.json -o output.json

Answer 4

Background-- I was trying to format a huge json file ~89mb on VS Code using the command (Alt+Shift+F) but the usuals, it crashed. I used jq to format my file and store it in another file.

A windows 11 use case is shown below.

step 1- download jq from the official site for your respective OS - https://stedolan.github.io/jq/

step 2- create a folder in the C drive named jq and paste the executable file that you downloaded into the folder. Rename the file as jq (Error1: beware the file is by default an exe file so do not save it as 'jq.exe' save it only as 'jq')

step 3- set your path variable to the URL of the executable file.

step 4- open your directory on cmd where the json file is stored and type the following command - jq . currentfilename.json>targetfilename.json

replace currentfilename with the file name that you want to format replace targetfilename with the final file name that you want your data formatted in

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within seconds you should see your target file in the same directory in a formatted version which can now be opened on VS Code or any editor for that matter. Any error related to the recognizability of jq as a command can be traced back with high probability to Error 1.