JSON.stringify() Serialize to JSON
Last updated: 2026-09-09
JSON.stringify() Serialize to JSON
JSON.stringify converts a JS value into a JSON string — the standard way to send data to APIs.
| Category | |
|---|---|
| ES version | ES5 |
📝 Syntax
const json = JSON.stringify(value, replacer, space);⚙️ Parameters
| value | The value to serialize. |
|---|---|
| replacer | Optional. A filter function or array of property names. |
| space | Optional. Number of spaces for pretty-printing. |
Returns：A JSON-formatted string.
Mutates the original：No (returns a new value)
▶ Example
Edit the code, press Run, and see the result in the output panel:
Output：
{"name":"Zhang","age":25}
{
"name": "Zhang",
"age": 25
}
{"name":"Zhang"}💡 Tip JSON.stringify(obj, null, 2) is the standard pretty-print.
⚠️ Warning Functions, undefined and Symbol are skipped; Date becomes ISO string; NaN/Infinity become null.
🌐 Browser support
| Browser |  Chrome |
 Edge |
 Firefox |
 Safari |
 Opera |
|---|---|---|---|---|---|
| JSON.stringify() | ✓ v1 | ✓ v12 | ✓ v1 | ✓ v1 | ✓ v1 |
| Supported by all modern browsers | |||||
🏷️ Related Items
💡 Related Cases
More case studies coming soon — check back later.
📚 Related Tutorials
❓ FAQ
QDoes JSON.stringify mutate the original?
ANo — it only generates a string.
QHow to pretty-print JSON?
APass the indent count as the third arg: JSON.stringify(obj, null, 2).
QWhich values are skipped?
AFunctions, undefined and Symbol are skipped; Date becomes ISO; NaN/Infinity become null.
