Online Metronoom — Gratis online tool

Free Online Metronome — Precise BPM with Tap Tempo

The Online Metronome is a free, browser-based tool for musicians, music students, and producers who need a precise, reliable tempo reference. Built with the Web Audio API and AudioContext scheduling, it delivers sub-millisecond timing accuracy that surpasses simple JavaScript timer-based metronomes. Functies include tap tempo detection, multiple time signatures, accent controls, visual beat indicators, and preset tempos for common musical markings.

Why Timing Accuracy Matters

Most web-based metronomes use setInterval or setTimeout for timing, which are subject to JavaScript's event loop delays. Under heavy browser load, these timers can drift by 10-50 milliseconds per beat, which is audible and disruptive for musicians. This metronome uses a fundamentally different approach: it schedules sounds ahead of time using AudioContext.currentTime, which is driven by the audio hardware clock. A lookahead scheduler runs setInterval only to queue future beats, while the actual playback timing is handled by the audio thread. This provides timing accuracy within microseconds, comparable to hardware metronomes.

Understanding Time Signatures

A time signature describes how many beats occur per measure and which note value gets one beat. The most common time signatures and their musical uses include:

• 4/4 (Common Time): Four quarter-note beats per measure. Used in the vast majority of pop, rock, hip-hop, and electronic music. The default choice for most practice sessions.
• 3/4 (Waltz Time): Three quarter-note beats per measure. Creates a "ONE-two-three" feel. Used in waltzes, many country songs, and classical minuets.
• 2/4 (March Time): Two quarter-note beats per measure. Creates a strong, marching feel with emphasis on beat one. Used in marches, polkas, and some Latin music.
• 6/8 (Compound Duple): Six eighth-note beats, grouped as two groups of three. Creates a lilting, swaying feel. Used in many Irish jigs, some blues, and ballads.
• 5/4 (Irregular): Five quarter-note beats, often grouped as 3+2 or 2+3. Famous examples include "Take Five" by Dave Brubeck and the "Mission: Impossible" theme.
• 7/8 (Irregular): Seven eighth-note beats, typically grouped as 2+2+3 or 3+2+2. Common in Balkan folk music, progressive rock, and some film scores.

Tap Tempo: How It Works

Tap tempo lets you set the BPM by tapping a button rhythmically. The tool records the timestamp of each tap and calculates the average interval between the last 4 to 8 taps. This averaging smooths out minor timing inconsistencies in your tapping. To use it effectively, tap along with the song or rhythm you want to match, and the BPM display will update in real time. After 4 taps, the detected BPM is typically accurate within 1-2 BPM.

Accent Patterns and Click Sounds

The metronome generates click sounds using OscillatorNeede, creating short sine wave bursts of approximately 30 milliseconds. Beat 1 (when accent is enabled) uses an 800 Hz tone at slightly higher volume, while beats 2, 3, 4, etc. use a 600 Hz tone. This pitch difference makes the downbeat clearly distinguishable without being jarring. The volume slider controls the overall output level through a GainNeede connected to the AudioContext destination.

Practice Tips for Musicians

• Start 20-30 BPM below your target tempo when learning new material, then gradually increase.
• Practice with the metronome for at least 5 minutes before turning it off to internalize the tempo.
• Use different time signatures to challenge your rhythmic flexibility.
• Try playing on the "and" of each beat (offbeats) to develop syncopation skills.
• Record yourself playing with the metronome, then listen back to identify timing inconsistencies.

Tempo Marking Reference

Musical tempo markings map to specific BPM ranges: Grave (20-40), Largo (40-66), Adagio (66-76), Andante (76-108), Moderato (108-120), Allegro (120-156), Vivace (156-176), Presto (176-200), and Prestissimo (200+). The preset buttons in this tool provide quick access to the most common markings, making it easy to set the correct tempo when practicing classical repertoire or following sheet music.

Browser Compatibility

This metronome works in all modern browsers with Web Audio API support, including Chrome, Firefox, Edge, Safari, and Opera. On iOS devices, audio playback requires a user gesture to start, which the Start button provides. For uninterrupted metronome playback on mobile devices, keep the browser tab in the foreground and ensure your device is not in silent mode.