Batch Timestamp Converter
Paste up to 10,000 Unix timestamps (one per line) or upload a .txt/.csv file. Mixed units are handled automatically.
Bulk Unix Timestamp Conversion
When working with server logs, database exports, or analytics data, you often encounter thousands of Unix timestamps that need to be converted to human-readable dates simultaneously. This batch converter handles the entire process in your browser — no uploads, no API calls, no rate limits.
The converter automatically detects the precision of each timestamp: seconds (10-digit), milliseconds (13-digit), microseconds (16-digit), and nanoseconds (19-digit). A mixed file — for example, a log that switches between second and millisecond precision — is processed correctly without any configuration.
Supported Input Formats
Plain text (.txt)
One timestamp per line, no header required
CSV / TSV (.csv)
All numeric-looking columns are scanned for timestamps
Pasted text
Paste from terminal output, database queries, or log files
Mixed precision
Seconds, ms, µs, and ns can coexist in the same input
Common Use Cases
- Log analysis — Convert nginx/Apache access log timestamps for human review
- Database exports — Humanize created_at / updated_at columns before sharing with stakeholders
- Analytics pipelines — Validate that event timestamps fall in the expected range
- API debugging — Decode timestamp fields from bulk API responses pasted as JSON
- Security audits — Audit login timestamps from exported user tables
Frequently Asked Questions
Is my data sent to a server when I upload a file?▼
No. All processing happens entirely in your browser using JavaScript. Your timestamps never leave your device. This makes it safe to use with sensitive log data or customer records.
How do I convert a specific column in a CSV?▼
Upload the CSV file and the tool will identify columns that contain Unix-timestamp-like values. You can then select which column to convert. Results export with the original data plus new human-readable date columns.
What is the difference between Unix seconds and milliseconds?▼
A 10-digit number like 1700000000 is seconds. A 13-digit number like 1700000000000 is milliseconds (JavaScript's Date.now() format). The converter auto-detects which unit each value uses.
Can I convert negative timestamps?▼
Yes. Negative Unix timestamps represent dates before January 1, 1970 UTC. They are displayed correctly in the output.
What export formats are available?▼
You can download results as CSV (with original value, UTC date, local date, ISO 8601, and relative time columns) or as JSON for further processing.