frequencyclock Open the frequency clock

Frequency Clock

A live clock paired with a pure-tone generator — watch the time and play any frequency (Hz) you like.

  • Free
  • No signup
  • Works offline
  • Instant

More on frequencyclock

Tone Generator Tone Generate a pure sine tone at any frequency from 20 Hz to 20,000 Hz. Online Clock Clock A plain, accurate digital clock showing the current time and date.

frequencyclock.net pairs a live clock with sound. The frequency clock shows the time and plays a pure tone at any frequency; the tone generator is the sound tool on its own; and there's a plain online clock too. All free, in your browser.

Sound, made simple

Generate clean sine tones for tuning, testing gear, or hearing checks, with the time on hand. Our guides explain frequency and hertz, tuning standards like 432 vs 440 Hz, and how to test your speakers and hearing — without the pseudo-science.

From our guides

Browse all articles →
432 Hz vs 440 Hz 432 Hz vs 440 Hz: What the Tuning Debate Really Means A balanced look at the 432 Hz versus 440 Hz tuning debate, explaining what concert pitch is, where the argument comes from, and why superiority claims remain unproven. 6 min read Frequency & hertz explained Are Healing Frequencies Real? A Skeptical, Honest Look A skeptical, evidence-based examination of healing frequency and Solfeggio claims, explaining where the beliefs come from and why they remain unproven rather than fact. 5 min read 432 Hz vs 440 Hz The History of A440: How We Agreed on Concert Pitch The story of how musicians came to agree on 440 Hz as concert pitch, why tuning varied wildly for centuries, and the myths that have grown around the standard. 5 min read Tone generator uses How to Tune an Instrument With a Reference Tone A step-by-step guide to tuning any instrument by ear with a pure reference tone, from choosing the right frequency to matching pitch and avoiding common mistakes. 6 min read Testing speakers & hearing Online Hearing Range Test: Find Your High-Frequency Limit How to run an informal hearing range test with a tone generator, find your high-frequency ceiling, understand what it means, and why it is no substitute for a real test. 6 min read Tone generator uses Playing a Background Tone While You Work or Focus A practical look at using a steady background tone to mask distractions and aid focus while you work, with tips on frequency, volume, and honest expectations. 6 min read Frequency & hertz explained Sine vs Square Waves: Why Waveform Shape Changes Sound How the shape of a sound wave changes what you hear, comparing pure sine tones with buzzy square and sawtooth waves, and why timbre matters as much as frequency. 6 min read Testing speakers & hearing How to Test Your Speakers' Frequency Response With Tones A hands-on guide to testing your speakers or headphones with pure tones, running a frequency sweep to find the limits, spotting buzzes and dead spots, and staying safe. 6 min read

Frequently asked questions

Is frequencyclock.net free?
Yes — free, no signup, no download.
Does it make health claims?
No. It's a practical tone-and-clock tool; be sceptical of strong 'healing frequency' claims.
Does it work on mobile?
Yes — it works in any modern browser; tap play to start a tone.