JSON Parser Online

A JSON parser reads JSON text and turns it into data a program can use: objects, lists, text, numbers and true/false values. It reads the text one character at a time, checks it follows JSON’s rules, and builds the structure. If a single comma or quote is wrong, it stops and reports where.

An online parser does the same thing in your browser, then shows you the result. This is useful when an API response, a log line or a config file won’t load and you need to see why, or when you need to find one value inside a large document.

JSON has six kinds of value. Here is what each one becomes after parsing:

1. Paste your JSON into the box, or use Open file or drop a .json file onto it. It is checked as you type.
2. Read the status line. Valid JSON shows its size and shape. Invalid JSON shows the line and column, what is wrong, and a pointer under the exact character.
3. Fix it. Go to line jumps to the problem. For pasted JavaScript or Python, Fix common mistakes changes single quotes, unquoted names, trailing commas, comments and True/False/None in one go, and you can undo it.
4. Explore the tree. Expand objects and arrays, search for a key or value, and click a row to copy its path or value.
5. Copy or download the result from Formatted, indented with 2 or 4 spaces or tabs, or minified onto one line.

For a picture of the whole structure, paste the same JSON into the JSON data graph.

Browsers and languages word the same mistake differently. These are the messages people see most, from Chrome (JavaScript) and Python:

The position in an error is where the parser gave up, which is often just after the real mistake. A missing comma at the end of line 3 is reported at the start of line 4. The pointer in the tool shows the same spot, so look at the character it points to and the one just before it.

Every major language has a built-in JSON parser:

// JavaScript
const data = JSON.parse(text);
const data = await response.json();      // from fetch()

# Python
import json
data = json.loads(text)                  # from a string
with open("order.json") as f:
    data = json.load(f)                  # from a file

// PHP: true gives arrays instead of objects
$data = json_decode($text, true);

// C# (.NET)
using System.Text.Json;
var doc = JsonDocument.Parse(text);
var price = doc.RootElement.GetProperty("items")[1].GetProperty("price").GetDecimal();

// Java (Jackson)
JsonNode data = new ObjectMapper().readTree(text);
int price = data.get("items").get(1).get("price").asInt();

To turn data back into JSON text, use JSON.stringify() in JavaScript or json.dumps() in Python. See JSON Stringify Online.

Watch out for long numbers in JavaScript. JSON.parse stores every number as a double, which is only exact up to 9,007,199,254,740,991. An ID like 1585741526539010048 silently becomes 1585741526539010000. That is why APIs often send IDs as text as well ("id_str"). This tool keeps the digits exactly as written and warns you when JavaScript would change them. Load the long ID example to see it.