DevToolsmith

Batch Timestamp Converter

Convert a list of numeric timestamps or ISO date-times at once. Preserve nanoseconds, keep row-level errors and export a CSV or JSON report.

Runs 100% in your browser — nothing is uploaded

One value per line, up to 1,000 rows. ISO date-times require Z or an explicit offset. Select a numeric unit when digit-count guessing would be ambiguous.

4 converted · 1 failed

  • not-a-timestamp

    Use a number or an ISO date-time with Z or an explicit UTC offset.

Timestamps (one per line)
Tip: drop a file here91 chars · 91 bytes · 5 lines
Converted timestamps and row errors
704 chars · 704 bytes · 6 lines

Convert one value per line

Paste seconds, milliseconds, microseconds, nanoseconds or ISO date-times with an explicit offset. For example, 2026-01-01T00:00:00.123456789Z retains all nine fractional digits. Invalid rows are reported without discarding successful rows.

Keep time-zone assumptions explicit

Bare local dates and date-times without an offset are rejected. Convert them with the Time Zone Converter first. Integer unit outputs use floor division; the exact nanosecond and UTC columns retain the original instant.

Frequently asked questions

Can I mix timestamp units?

Auto mode guesses each numeric row by digit count. This is useful for common present-day timestamps but ambiguous near the epoch or for unusually early or late dates. Select an explicit unit when all numeric rows use the same scale.

Will spreadsheet software preserve every digit?

The report emits exact decimal values, and JSON represents them as strings. A spreadsheet may round long numeric CSV cells when opening them. Use JSON or import columns explicitly as text. Smaller-unit integer columns are floored toward the earlier instant, including negative timestamps.