One value per line
Use line breaks when possible. Commas, semicolons and whitespace also work in separated-value mode.
Bulk Unix time conversion
Batch timestamp
converter
Paste a list or a section of log text and convert as many as 500 Unix values at once. Detect each unit separately, review invalid rows and export UTC, KST and exact ISO 8601 as CSV.
Prepare the input for reliable results
A consistent list is fastest to review, but extraction mode is useful when records include labels or surrounding log messages.
Mixed units
Select automatic detection when one list includes 10-digit seconds and 13-digit milliseconds.
Values inside text
Extraction mode searches for likely timestamp-sized decimal or hexadecimal values while leaving ordinary short numbers alone.
Review the detected unit. Digit length is a clue, not proof. Historical, negative and far-future values may not follow the present-day 10-digit and 13-digit pattern.
Using the CSV result
The exported table keeps the original value beside its interpretation so later readers can verify unit and date.
| Column | What it contains | Why it helps |
|---|---|---|
| Input | The original numeric text | Lets you compare with the source record |
| Detected unit | Seconds, milliseconds, microseconds or nanoseconds | Makes automatic assumptions visible |
| UTC | Readable universal date | Aligns records across regions |
| KST | Readable Korea date | Supports Korean schedules and reviews |
| Exact ISO 8601 | UTC string preserving supported fractions | Portable, explicit date-time format |
Spreadsheet tip Import very long timestamp columns as text. A spreadsheet may otherwise display scientific notation or round the last digits of a nanosecond value.
Limits and accuracy
The batch limit keeps the table responsive and makes invalid items manageable.
Maximum 500 values
Split larger files into groups. Each group should be small enough to compare with its source.
Exact integer handling
Long values are kept as integer text during conversion, avoiding ordinary floating-point rounding.
Calendar display range
A valid integer can still be too large to display as a conventional date. Such rows are marked as errors.
The Unix time basis is described by the POSIX time rationale. Use the Unix time guide for unit and 2038 details.
Batch conversion questions
Answers about list size, mixed units, extraction and CSV output.
How many timestamps can I convert at once?
You can convert up to 500 values in one operation. Divide larger input into smaller groups so errors remain easy to review.
Can a list contain both seconds and milliseconds?
Yes. Choose automatic detection to classify each row separately, or select one unit when every source value uses the same unit.
Can this tool extract timestamps from sentences or logs?
Yes. Extract mode finds likely 9- to 19-digit timestamp values and hexadecimal values inside surrounding text while ignoring ordinary short numbers.
Can I use the result in another document?
Use Copy CSV or Download CSV. The export includes the input, detected unit, UTC, KST and exact ISO 8601 columns.
Are pasted values stored?
No. The list is converted only on this page and is not transmitted or retained.
Related timestamp tools
Inspect one difficult value in detail or standardize its unit before processing a list.
Detailed date view
Timestamp → date
Compare one value across UTC, KST, your device and a selected city.
Inspect one value →Exact unitsSeconds ↔ milliseconds
Convert one instant across all four Unix units.
Convert units →Date stringISO 8601 validator
Validate the exported UTC string and its offset.
Validate a date →