UserBenchmark — Free Online CPU, GPU & PC Stress Test
Professional hardware detection and benchmarking, powered by your browser. Test your CPU, GPU, RAM, and full system performance with real-time path tracing, soft shadow rendering, and multi-stage stress tests — no downloads required.
What Makes This Different
Path Tracing Mode
Real-time ray-traced global illumination with realistic soft shadows. Extreme GPU load for serious stress testing.
Soft Shadow Rendering
PCSS shadows, dual-radius ambient occlusion, and volumetric god rays. Taxing for any GPU.
Multi-Stage Stress Test
CPU saturation via parallel workers, then GPU compute with Mandelbrot fractals, then VRAM pressure testing.
Live Frame Metrics
Frame time, throughput, and performance degradation tracked in real-time by your browser.
Adaptive Lite Mode
Auto-detects crawlers, low-end devices, and poor connections. Falls back gracefully to preserve performance.
Zero Installation
Runs entirely in your browser. No downloads, no admin rights, no background processes.
How It Works
- Start Test — Click to begin. Tests run only when you trigger them — nothing runs in background.
- CPU Stress — All logical cores saturated with continuous math operations for 60 seconds.
- GPU Compute — Mandelbrot fractals with blur and bloom effects rendered for 60 seconds.
- VRAM Pressure — Heavy texture uploads stress your GPU memory bandwidth for 60 seconds.
- View Results — Frame time, stability, and degradation metrics. Results live in your session only.
Built for Power Users
Enthusiasts, gamers, engineers — anyone who demands peak performance from their hardware.
- PC Builders — Quick stress check after assembly
- Overclockers — Stress test after overclocking to check for stability
- Content Creators — Quick GPU stress before intensive editing
- System Integrators — Rapid QA for assembled systems
Frequently Asked Questions
What is UserBenchmark and how does it work?
UserBenchmark is a free online benchmark tool that tests your CPU, GPU, RAM, and storage directly in your browser to show performance scores and compare against other users with similar hardware.
Does UserBenchmark stress test my CPU and GPU like dedicated benchmark tools?
UserBenchmark includes performance and load tests — but it is not the same as full stress-test tools like Prime95 or FurMark. Its GPU test uses WebGL graphics rendering to push the GPU; CPU tests include core performance and thread processing pressures.
Do I need to download anything to use UserBenchmark?
No — you can run UserBenchmark's tests directly in your browser without installing software.
Why did my PC restart or crash while running a benchmark?
Benchmarking and stress tests can push a system to its limits. Common causes for restarts include overheating, unstable overclocking, or an insufficient power supply under load.
Are UserBenchmark scores accurate and reliable?
There is a lot of debate. Some users find the scores useful for quick comparison, while others criticize the scoring methodology — especially for CPUs and cross-brand comparisons — and suggest treating results with caution and cross-checking with other tools like 3DMark or Cinebench.
Why does UserBenchmark sometimes show low performance even though my PC feels fast?
Benchmark scores are synthetic and don't always reflect real-world performance. Factors like background processes, cooling efficiency, and different workload uses can affect benchmark scoring.
Can benchmarking or stress testing damage my PC?
Not if done properly — but if a system has cooling issues, unstable overclocks, or insufficient power delivery, sustained stress tests can reveal these problems and may cause shutdowns or system resets to protect hardware.
What tools are better for stress testing my system?
For serious stress tests: Prime95 (CPU stress and stability), FurMark (intense GPU stress and thermal testing), and MemTest86 (RAM stability testing). These tools push individual components harder than basic benchmarks.
What precautions should I take before stress testing a PC?
Monitor temperatures (HWMonitor, HWiNFO64), ensure good cooling and airflow, close background apps, and set a reasonable stress duration instead of indefinite loops.