ISO 8601 Formatter
Convert any date to all ISO 8601 format variants — in real-time.
Ensure your dates comply with the ISO 8601 international standard. Parse dates from various formats into strict ISO 8601, or convert ISO dates to other human-readable formats.
Key Features
- ✓Parse any date string into ISO 8601
- ✓Validate existing ISO 8601 dates
- ✓Output variants: basic, extended, date-only, with offset
- ✓Duration format support (P1Y2M3DT4H5M6S)
- ✓Week numbering format (2026-W11-4)
- ✓Copy formatted output instantly
How to ISO 8601 Formatter
- 1
Enter a date in any format
Type or paste a date string — the parser supports dozens of common formats.
- 2
Select the ISO 8601 variant
Choose extended (2026-03-13), basic (20260313), with time, or duration format.
- 3
View the formatted result
See the properly formatted ISO 8601 string with optional timezone offset.
- 4
Copy the output
Click copy to use the formatted date in your code or document.
Common Use Cases
- •Standardizing dates in API request/response payloads
- •Formatting dates for JSON and XML data interchange
- •Ensuring compliance with international date standards
- •Converting legacy date formats to ISO 8601
Frequently Asked Questions
What is ISO 8601?▼
ISO 8601 is an international standard for representing dates and times (e.g., 2026-03-13T14:30:00Z). It eliminates ambiguity between date formats used in different countries.
What is the difference between basic and extended format?▼
Basic format omits separators (20260313T143000Z) while extended format includes hyphens and colons (2026-03-13T14:30:00Z). Extended is more common.
Does it support duration formatting?▼
Yes. ISO 8601 durations like P1Y2M3DT4H5M6S (1 year, 2 months, 3 days, 4 hours, 5 minutes, 6 seconds) are fully supported.