Convert tools

Batch Timestamp Converter

Convert lines of Unix seconds or milliseconds to ISO dates, or reverse the conversion.

Convert in your browser · No sign-up

Maximum 1000 lines; blank lines are preserved. ISO input requires an explicit offset or Z. Seconds are floored, including before 1970.

Up to 100,000 UTF-16 units per input and 1,000,000 per result. See the supported formats and examples below.

How to use

  1. Convert lines of Unix seconds or milliseconds to ISO dates, or reverse the conversion.
  2. Choose the mode or options, then run the tool.
  3. Review the result, then copy or download the TXT file.

Example

0 → 1970-01-01T00:00:00.000Z

Details and limitations

Maximum 1000 lines; blank lines are preserved. ISO input requires an explicit offset or Z. Seconds are floored, including before 1970.

Text stays in your browser; it is not sent to a conversion server.

FAQ

Batch Timestamp Converter — What are the supported inputs and limits?

Maximum 1000 lines; blank lines are preserved. ISO input requires an explicit offset or Z. Seconds are floored, including before 1970.

Format references

Tool page updated: