Audio Latency Test — output latency & A/V sync
An audio latency test measures the delay between your system requesting a sound and you actually hearing it — a critical signal in competitive gaming, where audio cues like footsteps and gunshots have to arrive in sync with the visuals on screen. Our free browser-based test reads your browser's reported output latency, runs an interactive A/V sync perception test (three trials, drag a slider until click and flash feel simultaneous), and optionally measures hardware round-trip latency through microphone loopback for users who want ground-truth verification. The result is a 0–1000 Audio Latency Score with letter grade — and for most users wearing Bluetooth headphones, it is the moment they discover how much latency the wireless connection is adding. No download required.
How the audio latency test works
Read your browser's reported output latency
The Web Audio API exposes an outputLatency property — the time between your system rendering a sound and the speakers producing it, including driver buffers, the OS mixer, and any wireless radio in the path. This is read instantly, in milliseconds. It is the canonical answer to "how delayed is my audio."
Run the A/V sync perception test
A click and a flash play simultaneously on a 1.5-second loop. You drag a slider to shift the click forward or backward in time until they feel perfectly aligned. The absolute value of the offset you settle on is your personal A/V perception threshold — a number most users have never measured for themselves. The test runs three trials so we can take the median and report your consistency across them.
Optionally measure hardware ground truth via mic loopback
For users who want to verify what their browser is reporting, the optional loopback test plays a 200-millisecond frequency chirp and records it back through your microphone. Cross-correlation against the original chirp finds the time delay — the actual round-trip latency through your audio stack. Requires microphone permission and a quiet room. Skipping is fine; the weight redistributes to the other signals.
Compose the four signals into a single score
Reported output latency carries 500 points (50%), mic loopback 200 (20%), perception offset 200 (20%), and perception consistency 100 (10%). When mic loopback is skipped, its 200 points redistribute proportionally so the total stays at 1000. Each signal is graded continuously against severity thresholds and contributes to the composite.
Get a letter grade and shareable card
The composite score maps to a letter grade (S 950+, A+ 900+, A 825+, B 725+, C 600+, D 450+, F below) — the same scale used by the Controller Health Score and FPS Score for consistency across the GPADLAB benchmark family. The result panel includes a Share Score button that generates a 1200×630 image with your number, grade, output device, and per-signal breakdown.
What the four signals mean
The four signals are graded independently and weighted into the composite. The reported output latency does most of the work; perception and consistency are the human-perception backstops that make sure the result is meaningful.
| Signal | Threshold (Healthy → Faulty) | What It Represents |
|---|---|---|
| Reported output latency | Healthy < 20ms · Functional < 40ms · Partial < 100ms · Faulty ≥ 100ms | Time from sound generation to your speakers, as reported by the browser. Wired headphones and onboard speakers usually fall under 40ms. Standard Bluetooth typically reads 100–300ms — the single biggest reason to know this number. |
| Mic loopback round-trip | Healthy < 30ms · Functional < 70ms · Partial < 150ms · Faulty ≥ 150ms | Actual measured time for sound to leave your speakers, travel through the air, and be picked up by your microphone. Confirms what the browser reports — or reveals discrepancies (some Bluetooth drivers underreport their latency). |
| A/V perception offset | Healthy < 20ms · Functional < 50ms · Partial < 100ms · Faulty ≥ 100ms | Your personal threshold for perceiving audio and visuals as simultaneous. Sharp perception (under 20ms) means you would notice even small latency adjustments. A wide threshold may indicate either an insensitive ear or a noisy trial — re-running gives a cleaner read. |
| Perception consistency | Healthy < 10ms · Functional < 25ms · Partial < 50ms · Faulty ≥ 50ms | Standard deviation across the three sync trials. Low variance means you consistently aligned the click and flash the same way — high variance suggests the result is closer to a guess. The composite score weights this so noisy runs do not dominate. |
Compatible audio setups
The test runs against whatever audio output is currently active. To compare devices, run the test, switch outputs, then run it again — the score difference quantifies what your hardware is costing you.
Common troubleshooting guides
Related diagnostics
Audio Latency questions
Bluetooth audio is compressed before transmission, sent over a packet-based wireless link, and decompressed in the headphones — each step adds time. Standard SBC codec adds 100–250ms. AAC and aptX cut this to 100–150ms. aptX Low Latency targets under 40ms but requires both transmitter and receiver to support it. Bluetooth LE Audio (LC3 codec) can go even lower. If your test shows high latency on Bluetooth, the codec and chip in your headphones are usually the limiting factor, not the host device.
A click sound and a screen flash play together on a 1.5-second loop. The slider shifts the click forward (right) or backward (left) in time relative to the flash. You drag until the two feel perfectly simultaneous. The absolute value of the offset you choose is your personal A/V perception threshold — a number that depends on your hearing, your visual sensitivity, and the actual latency in your audio chain. Three trials give us a median and a measure of how consistent you were.
Run it if you want to verify what your browser is reporting, or if you suspect your Bluetooth headphones are misreporting their latency (some do). Skip it if you do not want to grant microphone permission, you are in a noisy environment, or you trust the reported value. Skipping does not penalize your score — the 200 points allocated to mic loopback redistribute to the other three signals so the total stays at 1000.
Because they measure different things. Reported output latency is output-only (sound generation to speakers). Mic loopback is round-trip (output through speakers, across the room to your mic, then back into the browser). Expect the loopback measurement to be roughly twice the reported number plus a few milliseconds for air travel. If the loopback is much higher than expected, your hardware or driver may be adding latency the browser is not aware of.
The cross-correlation between the played chirp and the recorded audio was weak, usually because the recorded signal was too quiet (mic far from speakers, low playback volume) or too noisy (room background, other apps producing sound). Try moving your microphone closer to your speakers, increasing system volume, and re-running in a quieter environment. If the issue persists across attempts, the loopback path may be physically blocked (some laptop mics are heavily filtered to suppress speaker bleed).
Under 40ms reported output latency is the practical floor for competitive audio — beyond that, footsteps and abilities start arriving meaningfully late relative to visuals. Under 20ms is what wired audio enthusiasts consider transparent. Above 100ms is where most users start consciously noticing the lag. For ranked play, wired headphones or low-latency wireless (sub-40ms) are the safe choices.
Native low-latency APIs (ASIO on Windows, Core Audio on macOS) are more accurate but require driver-level access we cannot have from a webpage. The browser path is honest about its limits and works for 100% of users without a download. For users wanting absolute accuracy, the mic loopback path provides hardware ground truth — the chirp goes through every physical and software layer end-to-end.
Yes. The result panel includes a Share Score button that generates a 1200×630 image with your score, grade, output device name (when available), and per-signal breakdown. Mobile and modern desktop browsers open the native share sheet; older browsers copy the image to your clipboard so you can paste it into Discord, Twitter, Reddit, or anywhere else. Sharing scores is what powers the future Community Percentile Database — the more results in the dataset, the more meaningful the percentile comparisons.
How we calculate the Audio Latency Score
Four signals contribute to the composite. Reported output latency is read directly from the Web Audio API and converted to milliseconds (the property returns seconds), then graded against severity thresholds at 20, 40, and 100 milliseconds. The A/V sync perception test runs three trials with a click + flash loop, the user dials in a slider offset until perceived alignment, and we record the median absolute offset and the standard deviation across trials. Optional mic loopback measurement plays a 200-millisecond 1kHz→4kHz linear chirp through the speakers while recording the microphone stream, then cross-correlates the recorded signal against the original chirp to find the time offset — a confidence score from the normalized correlation peak determines whether the result is trusted (under 0.15 is rejected as too noisy). Each signal scores continuously across four severity buckets (healthy/functional/partial/faulty) within its weighted point budget. Skipped mic loopback redistributes its 200 points to the other three signals. Grade thresholds match the Controller Health Score and FPS Score families for cross-benchmark consistency. Methodology published by GPADLAB Engineering.
Run the full Controller Health Score
This test is one of six diagnostics in the composite score. See how your controller stacks up overall.
Run the Benchmark