Timestamp Converter
Convert between Unix epoch time and human-readable dates — seconds, milliseconds, ISO 8601, UTC, time zones, and relative time.
Prefer the terminal? See the CLI equivalent →About the Timestamp Converter
- Unix ⇄ ISO ⇄ human-readable
- Timezone aware
- Instant results
- 100% private — runs in your browser
- Free, no sign-up
Unix time — also called epoch time — is a single number representing the count of seconds since 1970-01-01 00:00:00 UTC. Because it is just an integer with no time zone attached, it is the standard way computers store and exchange moments in time: you will find it in log files, database records, API responses, JWT expiry claims, and cron schedules. The trade-off is that it is unreadable to humans, which is where this converter helps.
Paste an epoch value — in seconds, milliseconds, or microseconds, which the tool auto-detects — or any date string, and it shows you the equivalent in Unix seconds and milliseconds, ISO 8601, UTC, a time zone of your choice, and a human-friendly relative time such as “3 hours ago”. Conversions use the browser’s native Date and Intl APIs, so time-zone handling matches what your users’ browsers actually do.
Time zones and daylight saving are a common source of bugs. Storing and transmitting times as UTC epoch values and only converting to local time for display is the standard way to avoid them — this tool makes it easy to move between the machine representation and every human-readable form.
How to use it
- Enter a Unix timestamp (the tool detects whether it is in seconds, milliseconds, or microseconds) or paste a date string.
- Read the conversions: Unix seconds and milliseconds, ISO 8601, UTC, your selected time zone, and relative time.
- Change the target time zone to see the same instant expressed elsewhere in the world.
- Use the current-time readout as a live reference, and copy any representation you need.
Common time representations
- Unix seconds
- Seconds since 1970-01-01 UTC. The most common epoch form (e.g. JWT exp, many APIs).
- Unix millis
- Milliseconds since the epoch — what JavaScript’s Date.now() returns.
- ISO 8601
- A human- and machine-readable string like 2026-07-02T14:30:00Z. Unambiguous and sortable.
- UTC
- Coordinated Universal Time — the zero-offset reference all epoch values are measured against.
- Relative
- A friendly description such as “in 5 minutes” or “2 days ago”, relative to now.
Frequently asked questions
Is the timestamp in seconds or milliseconds?+
Both are common: Unix time is traditionally in seconds, but JavaScript and many APIs use milliseconds. This tool auto-detects the unit from the magnitude of the number (and also handles microseconds), and always shows you both seconds and milliseconds so there is no ambiguity.
How are time zones handled?+
An epoch value is an absolute instant with no time zone of its own. The tool displays it in UTC and in whatever time zone you select, using the browser’s Intl support so daylight-saving rules are applied correctly. Storing times as UTC and converting only for display is the recommended practice.
What is the year-2038 problem?+
Systems that store Unix time in a signed 32-bit integer overflow on 2038-01-19, after which the value wraps to a negative number. Modern systems use 64-bit timestamps, which push the limit billions of years out. This tool uses JavaScript numbers, so it is not affected for any realistic date.
Can I convert a human date back to epoch?+
Yes. Paste a date string — ISO 8601 works most reliably — and the tool shows the corresponding Unix seconds and milliseconds alongside the other representations.
Works well with
Timestamp Converter chains with these tools — send your result straight on:
Related tools
Code to UML
Turn TypeScript or Java source into a Mermaid class diagram — classes, interfaces, enums, fields, methods, inheritance, and interfaces — rendered live in your browser.
Color Converter
Convert colors between HEX, RGB, HSL, HSV, and OKLCH, with a picker, alpha, and a WCAG contrast checker — all in your browser.
CSS Unit Converter
Convert between CSS units — px, rem, em, pt, vw, vh, and more — with live visual feedback and a full conversion table.
Encoder / Decoder
Encode and decode text with Base64, URL, and Hex — UTF-8 safe, instant, and fully in your browser.
HEIC to JPG Converter
Convert iPhone HEIC/HEIF photos to JPG, PNG, or WebP — fast, multi-threaded batch conversion entirely in your browser. Nothing is uploaded, and location and metadata are removed by default.
Image Compressor
Fast, multi-threaded image compression — shrink many images at once by quality or to a target file size, with WebP/JPEG output and optional resizing, entirely in your browser.