JSON Stringify Online

Stringifying JSON wraps a whole JSON document in quotes and escapes everything inside, so the document becomes one text value. The result is still valid JSON, but now it is a string rather than an object. Any JSON reader turns it back into the original text, and reading that text gives you the object again.

• JSON inside JSON. Webhooks, message queues and logging tools often carry a payload as a string field:

• A database text column or setting. Some columns, environment variables and config values only take plain text. Stringify the JSON first so its quotes don’t break the value.
• A string literal in code. Pasting JSON into "…" in a test or a script needs every quote escaped. The output above can be pasted straight in, in JavaScript, Java, C# and most other languages.
• A URL parameter. Stringifying isn’t enough here. URLs need percent-encoding, so use JSON URL Encode instead.

Only a few characters change. Each gets a backslash in front, so the string’s own closing quote stays the only real one:

Each layer adds more backslashes. In the tool’s example, the text Hello, "Sam" is written \"Sam\" inside the JSON, and \\\"Sam\\\" once stringified: the backslash and the quote are each escaped again. Slashes, accents and emoji are left as they are.

In JavaScript, JSON.stringify(object) serializes an object into JSON text. Calling it on text that is already JSON stringifies it a second time, which is what this tool does:

const order = { id: 7, note: "Hi" };

const json = JSON.stringify(order);   // {"id":7,"note":"Hi"}          serialized
const str  = JSON.stringify(json);    // "{\"id\":7,\"note\":\"Hi\"}"  stringified

JSON.parse(str);                      // '{"id":7,"note":"Hi"}'  (text again)
JSON.parse(JSON.parse(str));          // { id: 7, note: "Hi" }   (the object)

So serializing goes from objects to JSON text, and stringifying JSON goes from JSON text to a JSON string. Undo it by parsing twice, or with Unstringify JSON.

// JavaScript
const str = JSON.stringify(JSON.stringify(data));

# Python
s = json.dumps(json.dumps(data))

// PHP: also escapes / as \/ unless you pass JSON_UNESCAPED_SLASHES
$s = json_encode(json_encode($data));

// C#: System.Text.Json writes the quotes as \u0022 by default (still valid)
string s = JsonSerializer.Serialize(JsonSerializer.Serialize(data));

// Java (Jackson)
String s = mapper.writeValueAsString(mapper.writeValueAsString(data));

The inner call serializes the data; the outer call turns that text into a string. All of these produce valid JSON strings, but the exact escapes differ a little between languages, so compare them by parsing, not by eye.