JavaScript Date toISOString() method is “used to convert the given data object’s contents into a string in ISO format (ISO 8601), i.e., in the form of (YYYY-MM-DDTHH:mm:ss.sssZ or ±YYYYYY-MM-DDTHH:mm:ss.sssZ).”
Syntax
dateObj.toISOString()
Parameters
This method does not take any parameters. It is used with a Date object created using the Date() constructor.
Return value
It returns the converted string of Date() constructor contents into ISO format (ISO 8601).
Example 1: Convert Current Date to ISO String
let currentDate = new Date();
let isoString = currentDate.toISOString();
console.log(isoString);
Output
2023-08-16T05:54:04.923Z
Example 2: Convert Specific Date to ISO String
let specificDate = new Date('December 25, 2025 23:59:59');
let isoString = specificDate.toISOString();
console.log(isoString);
Output
2025-12-25T18:29:59.000Z
Example 3: Adjust the Date and Convert to ISO String
This example sets a specific time and then converts the date to an ISO string:
let date = new Date();
date.setHours(14);
date.setMinutes(30);
date.setSeconds(15);
let isoString = date.toISOString();
console.log(isoString);
Output
2023-08-16T09:00:15.143Z
Browser Compatibility
Chrome | Edge | Firefox | Safari | Opera | IE |
Yes | Yes | Yes | Yes | Yes | 9-11 |
That’s it!
Related posts
JavaScript Date toTimeString()
JavaScript Date toLocaleDateString()

Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Python language stands as a testament to his versatility and commitment to the craft.