JSON Formatter Online — Format JSON with Proper Indentation & Structure
Paste your JSON above and it formats instantly — proper indentation, syntax highlighting, error detection. Everything runs in your browser, so your data never leaves your machine.
JSON Formatter Features
Converts compressed, single-line JSON into multi-line output with consistent 2-space indentation, making nested objects and arrays easy to scan.
Color-codes keys, string values, numbers, booleans, and nulls — so the structure of your JSON is immediately visible at a glance.
If your JSON has a syntax error, the formatter pinpoints the exact line and character, so you can fix it fast instead of guessing.
Switch between formatted (pretty) JSON for readability during development and minified JSON for production or API requests — all in one tool.
Upload a .json or .txt file directly from your computer, format it, and download the clean result.
All formatting happens locally in your browser. Your JSON data is never sent to any server — fully private and secure.
How to Format JSON Online — Step-by-Step
Input Your JSON Data
Got JSON from an API, a file, or just something you copied out of your terminal? Three ways to get it in:
.json or .txt file from your computerExample: Unformatted / Minified JSON Input
Here is what compact, unformatted JSON looks like before formatting:
{"name":"Sarah Chen","email":"sarah@company.com","age":29,"department":"Marketing","skills":["SEO","Content Strategy","Analytics"],"active":true}
Automatic JSON Formatting & Error Detection
No button press needed — the formatter runs the moment you paste. Here is what it does:
Example: Formatted JSON Output
The same JSON, now properly formatted with indentation and structure:
{ "name": "Sarah Chen", "email": "sarah@company.com", "age": 29, "department": "Marketing", "skills": [ "SEO", "Content Strategy", "Analytics" ], "active": true }
Choose Your Output Format
By default you get pretty-printed JSON with 2-space indentation. You can also switch to minified if you need it compact:
Copy or Download Your Formatted JSON
When it looks right, grab it:
Frequently Asked Questions — JSON Formatter
How do I format JSON online?
Just paste it in — the formatter runs immediately and outputs indented, highlighted JSON. If you have a file, use the Upload button instead. No account, no button to click, nothing to install.
What does a JSON formatter actually do?
It takes the compact, hard-to-read JSON you get from APIs or minified files and adds indentation and line breaks so you can actually read it. Think of it as the difference between one long run-on sentence and a properly paragraphed document — same content, completely different readability.
What is the difference between JSON formatting and JSON validation?
Formatting is about readability — adding indentation and structure. Validation is about correctness — checking whether the JSON is actually valid syntax. This tool does both at the same time, so if there is an error, you will see the exact line number before you even look for it.
Does it show syntax errors?
It does — missing comma, unclosed bracket, trailing comma, wrong quote type — it catches them and shows you the line. It does not auto-fix them though. If you want that, the JSON Fixer will repair most common issues automatically.
Can I format large JSON files?
Large files work fine — just upload the .json file directly rather than pasting, which avoids any browser paste size limits. Everything is processed locally so there are no server-side file size restrictions.
Does it work with API responses?
That is probably the most common use. Copy the raw response body out of Postman, browser DevTools, or curl output and paste it straight in. Nested objects, arrays of objects, deeply nested structures — it handles all of it.
Is it free?
Completely free, no account needed, no file size limits. Format as much as you want.