Test Your CPU Speed Right in the Browser

A free online CPU benchmark that runs entirely in your browser. Tests single-thread and multi-thread performance using math operations, string processing, and sorting algorithms via Web Workers. Includes a stress test mode to push all cores to 100%.

Benchmark single-core and multi-core performance with real workloads

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Stress test active — all cores at 100%
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Features

Single-thread benchmark: pi calculation, matrix multiplication, array sorting, regex matching Multi-thread testing via Web Workers — one worker per CPU core for parallel performance Stress test mode: runs all cores at 100% until you stop, with live per-core visualization Score history saved locally — compare results across sessions and devices

How to Benchmark Your CPU

  1. Click Run Benchmark. Press the button to start. The tool detects your core count automatically and runs four test phases.
  2. Wait for results. The benchmark takes about 20 seconds. Watch per-core activity in real time as tests progress.
  3. Review your score. See your total score (0–50,000 scale), single-thread and multi-thread breakdowns, and individual test results.

FAQ

How accurate is a browser CPU benchmark?

Browser benchmarks measure JavaScript engine performance, which correlates with real CPU speed. Results vary by browser (V8 in Chrome vs SpiderMonkey in Firefox) but are consistent within the same browser for comparing hardware.

What does single-thread vs multi-thread mean?

Single-thread tests measure one core's speed — important for apps like gaming. Multi-thread tests use all cores simultaneously — important for video rendering, compilation, and parallel workloads.

Will the stress test damage my CPU?

No. Modern CPUs have thermal protection that throttles or shuts down before damage occurs. The browser stress test cannot bypass these hardware safeguards. However, your device may get warm and fans will spin up.

Why is my score different each time?

Scores vary by 5–10% between runs due to background processes, browser tab activity, thermal throttling, and OS scheduling. Close other tabs and apps for the most consistent results.

What is a good CPU benchmark score?

Entry-level laptops score around 5,000–10,000. Mid-range desktops reach 15,000–25,000. High-end desktop CPUs (Ryzen 9, i9) can exceed 35,000–50,000 in multi-thread tests.

💡 Want us to improve this tool just for you?

We can — and it's free! Just send us a quick message with your idea. If you'd like to discuss it in detail, leave your email and we'll get back to you. You can stay anonymous.

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