Convert lists without losing row order
Paste one value per line or load the first column of a local text or CSV file. Every row keeps its original input, detected unit, converted ISO result, and an error field. Invalid rows do not stop valid rows from converting.
File privacy and limits
The file is read with browser APIs and is not uploaded. The current limit is 2 MB and 10,000 timestamp rows to keep the page responsive. The preview shows up to 100 rows; the download includes the processed result set.
Spreadsheet safety
Open exported CSV files with care when untrusted source values begin with spreadsheet formula characters. This converter writes fixed result columns and does not execute source content.
How to use this tool
Paste one timestamp per line or drop a TXT or CSV file. For CSV, select the timestamp column and explicitly check the header option if the first row contains column names. No first row is silently discarded. Choose a fixed unit for a uniform source, or automatic detection for a genuinely mixed file, then press Convert.
Worked input and output
| Input or setting | Expected result |
|---|---|
0 · s | 1970-01-01T00:00:00.000Z |
-1 · s | 1969-12-31T23:59:59.000Z |
1000 · ms | 1970-01-01T00:00:01.000Z |
Checks before using the result
Interior empty rows remain errors with their original line numbers. A final newline terminates the preceding record. Downloads include source row numbers, original CSV columns, exact nanoseconds, ISO UTC, precision notes and errors. The preview shows 100 rows, but export includes all processed rows. The 2 MB and 10,000-row limits are enforced; larger jobs should be split. Check units before importing the results.