Unix Timestamp Converter

Convert Unix timestamps to readable dates and back, with seconds or milliseconds and UTC reference. Free private timestamp converter in your browser.

How to Use

1. For timestamp to date: paste the number and check Milliseconds if needed.
2. Click Timestamp -> Date to see local and optional UTC breakdown.
3. For date to timestamp: set the datetime picker value.
4. Click Date -> Timestamp to generate seconds or milliseconds.
5. Use Use current time to snapshot now for log correlation.
6. Copy results into tickets, queries, or code comments.

Input Field Guide

Unix timestamp

Integer seconds or milliseconds since 1 Jan 1970 UTC. Toggle milliseconds for 13-digit JS values.

Input is milliseconds

Check when the source value has 13 digits typical of JavaScript Date.now().

Human date

Local date-time for reverse conversion to epoch.

Show UTC reference

When checked, displays coordinated universal time alongside local interpretation.

Understanding Your Results

Forward conversion shows local date-time plus UTC when enabled, with seconds and milliseconds echoed for verification. Reverse conversion outputs integer epoch in the selected precision. Detail chips clarify which unit mode was active to prevent order-of-magnitude mistakes.

Features

• Bidirectional seconds and milliseconds conversion
• UTC reference toggle
• Use current time shortcut
• Local and UTC display
• Copy-friendly output
• No server round trip

Formula & Calculation Logic

date = new Date(ms) where ms = seconds*1000 or raw milliseconds; reverse: floor(ms/1000) or ms from UTC instant of local picker interpretation.

Real-World Use Cases

• Log line timestamp decoding
• API payload debugging
• Database epoch column verification
• JWT exp and iat inspection
• Cross-team incident timeline alignment

Practical Examples

Benefits

• Prevents seconds vs milliseconds mix-ups
• UTC toggle aids global teams
• Private for security log work
• Faster than shell date commands on locked-down PCs

Tips & Best Practices

• Count digits: 10 ≈ seconds, 13 ≈ milliseconds.
• Enable UTC when comparing with server logs stamped Zulu.
• Use epoch-converter for strict seconds-only labeling.

Common Mistakes to Avoid

• Forgetting milliseconds toggle on JavaScript timestamps.
• Treating local picker output as UTC without checking the UTC line.
• Multiplying already-millisecond values again.

Frequently Asked Questions

Related Date & Time Calculators

• Epoch Converter
• Iso Converter
• Json Date Formatter
• Timezone Calculator
• Time Difference
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