Sand Fox (Posts about json5)

JSON5 Tools

2025-07-11T05:46:00+03:00

Presenting a couple of JSON5 tools I built.

The first one was done a year ago, a docker CLI image to convert JSON5 to JSON: arokettu/json5-to-json.

$ echo "{ hello: 'world' }" | docker run -i --rm arokettu/json5-to-json
{"hello":"world"}

A simple tool to convert your configs on the build phase without installing anything into your images.

The second one is a builder/serializer that is aimed at creating pretty configs in PHP: arokettu/json5-builder.

While it can just serialize some data into JSON5, the goal is to create nice configs with comments and custom formatting.

<?php

use Arokettu\Json5\Json5Encoder;
use Arokettu\Json5\Values\CommentDecorator;
use Arokettu\Json5\Values\HexInteger;

require __DIR__ . '/../vendor/autoload.php';

$config = new CommentDecorator(
    [
        'bareKeys' => '<- Look, no quotes!',
        'value' => new CommentDecorator(
            new HexInteger(0xFFF),
            commentAfter: 'This is a very important value'
         ),
        'notAvailableInJSON' => [NAN, INF],
        'end' => 'auto trailing comma ->'
    ],
    commentBefore: 'This is my cool JSON5 config!',
);

echo Json5Encoder::encode($config);

// This is my cool JSON5 config!
{
    bareKeys: "<- Look, no quotes!",
    value: 0xFFF, // This is a very important value
    notAvailableInJSON: [
        NaN,
        Infinity,
    ],
    end: "auto trailing comma ->",
}

A Case for JSON6

2025-04-19T06:43:00+03:00

Just a required follow up for the previous post: JSON5 sucks too, like any other possible format. Just look at this:

{
    certificate: "\
-----BEGIN PRIVATE KEY-----\n\
MIIBVQIBADANBgkqhkiG9w0BAQEFAASCAT8wggE7AgEAAkEAt6wGEsfdarMo9KET\n\
sNv9gpBWkGfhIq3/Jhr14+3d8TXprmTk/XWReo5DA3+SbB7ebF3xUtN/4K5lUkcG\n\
1AbdywIDAQABAkBuMbfnFqAhvuFoeydMKYAcECrPMnOhEdENdIlnuTM53kBf18f/\n\
KaWRWv8ViuZ31GpArY8cBzj0YG30vE49Il8ZAiEA7PpotzcpjNcMKnwEBm3q0c6H\n\
3RRZD6i32Q/vXcQBeB0CIQDGaj4BJ/fuqiHvKzetfjhpOD+sYr3VDgEyjTcojhzZ\n\
BwIgTBRYafmbrUuc7EbERAwlxxW3KJLPxOc1nsou3rt+fUECIQCjBGUfJAyDDUtG\n\
KpbbN0n3wRwncRUQuCnps7Zu3pv6/wIhAIIcKty7O0T7auctlpMSdyw6vp0w818x\n\
namFjg3cbBs4\n\
-----END PRIVATE KEY-----\n"
}

Is JSON5 a better JSON?

2025-04-16T06:10:00+03:00

Yes it is, at least when it comes to configuration files.

As I said earlier, JSON is a good serialization language but a terrible config language. JSON5 builds on its strong sides: it's backwards compatible with JSON and is still a subset of JavaScript and it is still relatively easy to parse. Then it adds all the good stuff like unquoted keys, trailing commas, and a must-have thing for any config, comments. For me it has only two real downsides, both really minor. First is, as most config-oriented languages, it's tricky for automated modification, a feature it shares with TOML and YAML. The second one is JSON6, while ES6 syntax sugar is nice, it's just a 15th competing standard, and the worst, competing with itself.