Unix Timestamp Converter — Epoch to Date
Paste an epoch timestamp or a date, get the other one back. The unit is auto-detected by magnitude, and the maths runs on arbitrary-precision integers, so a 19-digit nanosecond value round-trips digit-for-digit instead of being silently rounded.
How to use it
- Install the extension from the Chrome Web Store and pin it to your toolbar.
- Click the toolbar icon to open the popup — it works in either direction, no mode to choose first.
- Paste an integer epoch (seconds, milliseconds, microseconds, or nanoseconds) — the unit is auto-detected by magnitude, with one-tap overrides if you want to force it.
- Or paste a date instead — ISO-8601, RFC 2822, “YYYY-MM-DD HH:mm:ss”, or looser natural language. An “interpreted as: …” line always shows how your input was read.
- Copy the output you need — local time and UTC side by side, or all four epoch units, each with its own copy button.
What you get
Free
- Epoch to human: local time and UTC side by side, in ISO-8601 and readable form, plus relative time (“3 hours ago”). Pre-1970 negative epochs work.
- Human to epoch: output in seconds, milliseconds, microseconds, and nanoseconds at once, each separately copyable.
- Automatic unit detection across s / ms / µs / ns, with manual override.
- Arbitrary-precision integer maths — nothing is silently rounded or truncated at nanosecond scale.
- A Now button showing the current moment in all four units, ticking live.
- Your unit default, time format, and theme are remembered between sessions.
Premium — $5, paid once
- Batch conversion — paste a whole column of timestamps, mixed units fine, each line auto-detected on its own; copy back as text or CSV.
- Custom output format strings with simple tokens, saved under names for reuse.
- A pinned multi-timezone panel — pin up to 8 timezones and see every conversion resolved in all of them at once.
No subscription and no account: pay once, keep the features.
What it can and can’t see
It requests exactly one Chrome permission: storage, used to remember your preferences on your own device. It declares no host permissions and injects no content scripts, so it cannot read the pages you visit, your open tabs, or your browsing history. The timestamps you paste are processed locally, inside the popup.
Our own code collects nothing — no analytics, no telemetry, no tracking of any kind, in this extension or any other we ship.
One honest exception, disclosed: the extension bundles ExtensionPay to handle the premium upgrade, and that component does make network calls — it checks whether you have purchased, and opens its hosted checkout if you choose to upgrade. ExtensionPay writes an install timestamp for every user from the moment of install, and after a purchase holds a licence key and the checkout email you gave it. Card details go directly to ExtensionPay and Stripe and are never seen by us. The full disclosure is in our privacy policy. That is the only network traffic involved — your timestamps are never part of it.
Try it
It is free to install, and the core features above stay free.