Jackson Cooper
Audio Systems Engineer & Web Audio Latency Researcher | Founder, SoundLatencyTest.com
Most audio tools on the web measure something about you — your pitch, your tempo, your vocal range. When I started building SoundLatencyTest.com, I was interested in a different problem entirely: measuring the system you are working on.
My name is Jackson Cooper. I have spent years studying how browsers handle audio timing, and specifically why the gap between when a sound is scheduled to play and when you actually hear it — and when the microphone captures it — is so difficult to pin down reliably. That gap is audio latency, and for anyone who records, performs, mixes, or develops with sound, it is one of the most practically important figures you need to know about your own setup. The problem is that almost nobody documents it clearly, and almost no browser-based tool measures it with any real technical rigour.
A 256-sample audio buffer at a 44,100 Hz sample rate introduces approximately 5.8 milliseconds of processing latency — before you add OS audio driver overhead, hardware interface delay, or the browser’s own scheduling uncertainty. Stack those sources together on a typical consumer machine and you can easily reach 30, 50, or even 100+ milliseconds of round-trip delay. That is the difference between a performance that feels tight and a workflow that feels broken. SoundLatencyTest.com exists to give you a real number for your real environment, explained in plain terms. To understand exactly how the measurement is made, see the How It Works page.
What I Research and Write About
Web Audio API Architecture and Browser Latency The Web Audio API exposes two latency properties — baseLatency and outputLatency — that most developers never inspect and most musicians never hear about. I research how these values are computed across browsers and operating systems, why they differ between Chrome, Firefox, and Safari, and how AudioContext scheduling relates to the actual moment sound leaves your speakers. Understanding this layer is the foundation of everything SoundLatencyTest.com measures.
Operating System Audio Pipelines The browser does not talk directly to your hardware. On Windows, audio flows through WASAPI or the legacy WDM audio stack before reaching a driver. On macOS, it passes through Core Audio. On Linux, through ALSA or PipeWire. Each layer adds buffering and each layer adds latency. I write about these differences because they determine why two users on different machines see completely different results from the same browser tool — and why that is expected, not a bug.
Hardware Interface and Monitoring Chain Latency External audio interfaces use ASIO drivers on Windows and Core Audio on macOS to achieve low-latency monitoring. Built-in laptop audio typically cannot get close to the latency figures a dedicated interface provides. Bluetooth audio adds codec encoding and decoding overhead — typically 40–200 ms — that makes it unsuitable for latency-sensitive work. I document the practical hierarchy of hardware choices and what each means for measured round-trip delay. If your results are unexpectedly high, the Troubleshooting page covers the most common hardware and browser causes.
Audio Latency in Music Production and Live Performance For a musician using a DAW, latency is not an abstract number. It determines whether software monitoring feels in time with the performance, whether a virtual instrument responds naturally to a MIDI keystroke, and whether a click track in headphones stays locked to the beat. I write about how to interpret latency measurements in practical terms — what is acceptable for each use case and what thresholds require action. The FAQ covers the most common questions about what your result means in practice.
Why I Built This
When I was diagnosing audio monitoring delay on my own recording setup, I found two types of resources: highly technical academic papers on web audio scheduling that required signal processing expertise to parse, and consumer guides that said things like “try lowering your buffer size” without explaining what a buffer is or what lowering it actually does.
What I could not find was a straightforward browser tool that measured round-trip audio latency precisely, showed me the result in milliseconds, and explained what that number meant in language a working musician or developer could use immediately.
The measurement approach implemented on this site uses the Web Audio API to emit a short tone burst through the system output and simultaneously captures the microphone input stream. Cross-correlation between the output signal and the captured input identifies the time offset between them — the round-trip latency — in milliseconds. This is the same principle used in professional acoustic measurement, applied to the browser environment where most modern audio tools actually run.
The goal was not to build another tool that tells you something approximate. It was to build one that tells you something true about your specific machine, browser, and audio hardware — with enough explanation that you know what to do with the result.
Accuracy Standards
Every measurement description on SoundLatencyTest.com is cross-referenced against the Web Audio API specification (W3C), the behaviour documented in browser source and DevTools, and where applicable, independent verification against hardware latency figures reported by professional audio interfaces. Latency values cited in educational content on this site reflect real measurement ranges, not idealised estimates. Limitations are always stated: consumer microphone frequency response, OS audio processing variables, and Bluetooth codec overhead are documented explicitly so readers understand exactly what factors influence the number they see.
All content on this site is written and reviewed by me personally. For a full account of how pages are researched, written, and updated, see the Editorial Guidelines.
Tools on This Site
- Sound Latency Test — soundlatencytest.com
Get in Touch
For content corrections, technical questions, or data requests, visit the Contact page or email directly: contact@soundlatencytest.com
Response times: technical and content questions within 48–72 hours. Privacy and data requests within 7 business days. GDPR requests within 30 days. CCPA requests within 45 days.
Jackson Cooper is the founder and sole author of SoundLatencyTest.com. Last updated: June 2026.