JSON Format Online

How to do it

1. Open JSON Formatter from any device — no download or install required.
2. Paste the JSON you got from an API client, log line or config file.
3. Format with two-space indentation and copy the result for review or sharing.

Why format JSON in the browser

Formatting JSON online removes the friction of reaching for a CLI. You do not need jq installed, you do not need to remember Python's json.tool flags, and you do not need to write a temporary file just to look at a payload. A browser-based formatter is the fastest path from 'I have a wall of unreadable JSON' to 'I can see the structure'.

It also works when you cannot install software — locked-down work laptops, freshly provisioned servers accessed through a jump host, or a tablet you happened to grab. The same URL works everywhere your browser does.

Indent options that matter in practice

Most teams pick two-space indentation because it matches what you get from JSON.stringify(value, null, 2) in JavaScript and json.dumps(value, indent=2) in Python. That makes the formatted output easy to drop into a code review or docs without surprises. Tabs are uncommon in JSON but readable in some editors. Four-space indentation is heavier visually and rarely worth it for JSON specifically.

• Two-space indent: matches JS/Python conventions, the default for code review.
• Four-space indent: easier on small fonts, but takes more horizontal space for nested objects.
• Tab indent: lets each reader pick their own width, but breaks JSON.stringify defaults.

What 'online' does not mean

Online here does not mean 'uploaded to a server'. The JSON Formatter on this site runs the format step entirely in your browser using JSON.parse plus a stringify pass. Your payload is not transmitted, not logged and not used for training. The only network calls on the page are static asset loads and Google Analytics for anonymous traffic stats.

Examples

{"id":42,"customer":{"name":"Ada","plan":"pro"},"items":[{"sku":"A1","qty":2},{"sku":"B7","qty":1}]}

{
          "id": 42,
          "customer": {
            "name": "Ada",
            "plan": "pro"
          },
          "items": [
            {
              "sku": "A1",
              "qty": 2
            },
            {
              "sku": "B7",
              "qty": 1
            }
          ]
        }

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