# AtomicClock: Exact NTP Time

> Precise atomic time — UTC clock, Greenwich Time Signal and clock widget

Canonical page: [https://chrome-stats.com/d/partl.atomicclock](https://chrome-stats.com/d/partl.atomicclock)

## Overview

- **ID:** `partl.atomicclock`
- **Platform:** Android
- **Type:** Android app
- **Status:** Available
- **Publisher:** Timo Partl
- **Category:** TOOLS
- **Downloads:** 606,436
- **Rating:** 4.73 / 5 (18,593 ratings)
- **Version:** 2.1.21
- **Last updated:** 2026-08-06
- **First published:** 2017-11-20
- **Publisher country:** DE
- **Size:** 7.84 MB
- **Data as of:** 2026-09-23
- **Store listing:** [Google Play Store](https://play.google.com/store/apps/details?id=partl.atomicclock)
- **Website:** [https://atomicclock.app/](https://atomicclock.app/)
- **Privacy policy:** [https://atomicclock.app/privacypolicy](https://atomicclock.app/privacypolicy)

## Description

AtomicClock is a Chrome extension that provides the most accurate current time by connecting to NTP servers synchronized directly with real atomic clocks. Whether you want to celebrate a special moment or perfectly synchronize your clocks, AtomicClock delivers precise time in various formats including analog and digital.

Key features include selecting from multiple time servers or adding your own, toggling between local time and UTC, choosing 12-hour or 24-hour formats, and customizing widgets displaying both time and date. The extension also offers an acoustic ticking sound and a fluid second hand for a realistic clock experience. Additional technical info like round trip time, stratum, and the Greenwich Time Signal are available for enthusiasts and professionals alike. AtomicClock ensures that your timekeeping is exact and reliable right within your browser.

## Rankings

- #90,511 — Overall

## Permissions and access

### Permissions

- `android.permission.ACCESS_ADSERVICES_AD_ID`
- `android.permission.ACCESS_ADSERVICES_ATTRIBUTION`
- `android.permission.ACCESS_ADSERVICES_TOPICS`
- `android.permission.ACCESS_NETWORK_STATE`
- `android.permission.FOREGROUND_SERVICE`
- `android.permission.INTERNET`
- `android.permission.READ_BASIC_PHONE_STATE`
- `android.permission.WAKE_LOCK`
- `com.android.vending.BILLING`
- `com.android.vending.CHECK_LICENSE`
- `com.google.android.finsky.permission.BIND_GET_INSTALL_REFERRER_SERVICE`
- `com.google.android.gms.permission.AD_ID`
- `partl.atomicclock.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION`

## Review summary

Users praise AtomicClock for precise, atomic-timed display and its usefulness as a reference tool with customizable widgets and faces. It’s viewed as reliable and worth paying for by many. Repeated negatives focus on intrusive ads, pricing concerns, occasional OS-related glitches, and missing features such as manual sync and AOD support.

### Pros

- Accurate time displayed and synced to atomic clocks (stays locked to the US Atomic Clock) with sub-second precision.
- Very useful as a reference tool with home-screen widgets and the ability to compare device time against multiple time servers; helps set analog watches.
- Highly customizable UI with many clock faces, colors, and hand options.
- Reliable and well-regarded; many users consider it the best clock app and are happy to pay for the Pro version.
- Positive perception of value and quality, with praise for ongoing support and development.

### Cons

- Intrusive ads, including full-screen pop-ups that cover the clock and disrupt use.
- Ads consistently interfere with usability, leading some users to switch to other apps.
- Pricing concerns and perceived inflation of Pro features; some users want more options without paying for Pro.
- Occasional issues after OS updates (or resets to local time) affecting reliability.
- Missing features like manual synchronization and Always-On Display (AOD) support; minor formatting requests (e.g., removing leading zeros) surface as well.

## Similar extensions and apps

- [Atomic Time - NTP Clock Sync](https://chrome-stats.com/d/com.twiegold.atomictime) — 189,387 users, 4.83 / 5
- [Atomic Clock](https://chrome-stats.com/d/com.fsphost.atomicclock) — 73,070 users, 3.90 / 5
- [Atomic Clock & Watch Accuracy](https://chrome-stats.com/d/net.hubalek.android.apps.atomic_clock_watch_accuracy_tool) — 471,521 users, 4.82 / 5
- [Atomic Dial](https://chrome-stats.com/d/com.theatomicdial.app) — 8 users
- [Time Calibrator](https://chrome-stats.com/d/com.xonix.timecalibrator) — 125,993 users, 4.28 / 5
- [Tempo · Atomic Watch Sync](https://chrome-stats.com/d/fr.benju.tempo) — 204 users
- [Golden Time](https://chrome-stats.com/d/com.revercode.klock) — 736 users
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- [MaruWatch - Standard Clock](https://chrome-stats.com/d/my.secwatch) — 295,712 users, 4.50 / 5
- [Momentix: Huge Digital Clock](https://chrome-stats.com/d/com.werhal.atomicdigitalclock) — 14,911 users, 4.88 / 5
- [NanoClockX](https://chrome-stats.com/d/com.nanoclockx) — 16 users
- [DigiClock](https://chrome-stats.com/d/com.agv.digiclock) — 22 users

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Source: [Chrome-Stats](https://chrome-stats.com/d/partl.atomicclock)