git404hub

what is timer.js fr?

mrdoob/timer.js — explained in plain English

Analysis updated 2026-07-27 · repo last pushed 2012-08-16

65JavaScriptAudience · developerComplexity · 2/5DormantSetup · easy

tl;dr

A tiny JavaScript timer that keeps browser animations perfectly in sync with audio playback by tracking elapsed time independently, avoiding drift in the audio element's clock.

vibe map

mindmap
  root((repo))
    What it does
      Tracks elapsed time
      Syncs visuals to audio
      Avoids audio drift
    Use cases
      Music visualizers
      Interactive art
      Rhythm animations
    Tech stack
      JavaScript
      Browser audio API
      Animation loops
    Audience
      Creative coders
      Visual artists
      Web animators

Code map

Detail Auto

An interactive map of this repo's files and how they connect — its source is parsed live in your browser. Click Visualize to build it.

filefunction / class

what do people make with this?

VIBE 1

Build a music visualizer where animations stay locked to the beat of an audio track.

VIBE 2

Create interactive art pieces where visuals respond precisely to audio playback time.

VIBE 3

Synchronize rhythm-based web animations with audio so visuals never drift out of sync.

what's the stack?

JavaScript

how it stacks up fr

mrdoob/timer.jscws6206/lucerne-geo-ai-searchingpolyhelper/polyhelper
Stars656565
LanguageJavaScriptJavaScriptJavaScript
Last pushed2012-08-16
MaintenanceDormant
Setup difficultyeasymoderatehard
Complexity2/53/54/5
Audiencedevelopergeneraldeveloper

Figures from each repo's GitHub metadata at analysis time.

how do i run it?

Difficulty · easy time til it works · 5min

Just include the JavaScript file and call play() alongside your audio element, no external dependencies required.

No license information is provided in the README, so usage rights are unclear.

in plain english

timer.js solves a surprisingly specific problem: when you're building something in the browser that needs to stay perfectly in sync with an audio file, the browser's built-in audio timing can let you down. Instead of relying on the audio element's clock, this library gives you a lightweight JavaScript timer that tracks elapsed time independently, so your animations and visual effects stay locked to the music. The idea is simple but clever. You tell the timer how long your audio track is, say, 40 seconds, and then call play() on both the audio element and the timer at the same time. From that point on, instead of reading the current playback position from the audio element itself, you read it from the timer. This sidesteps issues where the audio element's time reporting can drift, stutter, or become unreliable, particularly in longer or more complex browser-based projects. The library is clearly designed for people building audio-driven visual experiences in the browser, think music visualizers, interactive art pieces, or rhythm-based web animations where visuals need to match the beat. The example code shows an animation loop where an object's position is tied directly to the elapsed time, which is a pattern common in creative coding and projects built with libraries like Three.js (notably, the author is also the creator of Three.js). What stands out is how minimal this solution is. Rather than building a full-featured audio synchronization library, it does one thing: provides a reliable time tracker that mirrors what an audio element should be doing. The README doesn't go into detail about edge cases, browser compatibility, or what specific audio timing problems it works around, but the existence of the project suggests those problems are real enough that someone who builds browser-based 3D graphics for a living felt the need to create his own fix.

prompts (copy fr)

prompt 1
I have an audio element playing a 40-second track and an animation loop. Help me integrate timer.js so the animation stays perfectly synced to the audio by reading elapsed time from the timer instead of the audio element.
prompt 2
I'm building a music visualizer in the browser using Three.js. Show me how to use timer.js to track elapsed time so my visual effects stay locked to the music without drifting.
prompt 3
Help me set up a simple browser animation where an object's position is driven by elapsed time from timer.js, with play and pause controls matching the audio element.

Frequently asked questions

what is timer.js fr?

A tiny JavaScript timer that keeps browser animations perfectly in sync with audio playback by tracking elapsed time independently, avoiding drift in the audio element's clock.

What language is timer.js written in?

Mainly JavaScript. The stack also includes JavaScript.

Is timer.js actively maintained?

Dormant — no commits in 2+ years (last push 2012-08-16).

What license does timer.js use?

No license information is provided in the README, so usage rights are unclear.

How hard is timer.js to set up?

Setup difficulty is rated easy, with roughly 5min to a first successful run.

Who is timer.js for?

Mainly developer.

peek the repo → explain another one

This repo across BitVibe Labs

double-check against the repo, no cap.