Why is the score different every run?

CPU turbo boosts, thermal throttling, and background tasks can swing results. Run twice after warming up for a stable average.

Does this reflect WebAssembly speed?

No—this test is JS-only. WASM performance can differ; if you rely on WASM, test that separately.

How do I compare to another device?

Run the test on both devices in the same browser channel (e.g., Chrome stable) and similar power mode for a fair comparison.

Browser Diagnostics

JavaScript Speed Test

Client-side benchmark with live progress

JavaScript Speed Test

CPU-bound micro-benchmarks for JavaScript performance

Ready to test

Interpreting your score

We run CPU-bound micro-benchmarks (math, array ops, JSON) to give a quick proxy for main-thread performance. Higher scores mean faster script execution and lower input latency in web apps, but GPU and network still matter for real workloads.

Close background tabs, set laptop power mode to “Performance,” and plug in your device to avoid throttling. Mobile browsers may cap CPU bursts to preserve battery, so compare against similar devices, not desktops.

Optimize slow results

Update your browser, enable hardware acceleration, and make sure WebGL isn’t falling back to software.

Fix a slow browser →Hardware acceleration Check GPU path

FAQ

Why is the score different every run?: CPU turbo boosts, thermal throttling, and background tasks can swing results. Run twice after warming up for a stable average.
Does this reflect WebAssembly speed?: No—this test is JS-only. WASM performance can differ; if you rely on WASM, test that separately.
How do I compare to another device?: Run the test on both devices in the same browser channel (e.g., Chrome stable) and similar power mode for a fair comparison.