Check Your PC's Speed with an Online CPU Benchmark

When you buy a new PC, or when an old one starts to feel slow, you may want to see its performance as a number. Desktop benchmark programs mean downloading and installing software, but an online CPU benchmark is as simple as opening a page and pressing a button. Web Bench runs real tasks inside the browser, such as text processing, JSON parsing, compression, hashing, image processing, sorting, pathfinding, physics simulation, ray tracing and linear algebra. It does not guess a score from a product name or a spec sheet. It shows exactly how fast this device just did the work. No account or login is required, and results are sent to a server only with consent to join the rankings. The biggest benefit is that you directly measure the performance of the environment where you actually use web apps and web pages. We explain the basic flow step by step so that even first-time users can follow along without stress.

CPU results are split into single and multi. Single is how fast one core finishes one job, so it is close to the feel of tasks that run in a single line, such as page loading, document editing and app responsiveness. Multi is the throughput when the same job is divided among several Workers, so it is close to work that can be split in parallel, such as video conversion and large file processing. Comparing the two suggests whether the device gains performance from its core count or from the strength of each core. However, the multi ratio depends on how many Workers the browser uses and how it synchronizes them, so do not convert it directly into physical cores or clock speed. A higher number means more work done in the same time. For example, if you measure the same laptop separately on wall power and on battery, you can see the effect of power settings directly in the numbers.

Start with the quick test of about 30 seconds to see the rough level, then run the standard test of about 2–3 minutes when you want more detail. Before testing, pause downloads and video playback in other apps, and on a laptop, plug in the charger and note the power mode. Do not hide the tab during the test. If you hide it, the round in progress is discarded and measured again when you return. Rather than drawing a conclusion from a single run, it is safer to run two or three times under the same conditions and look at the range. Results are saved for the last 5 runs in this browser so you can compare them, and you can also download a PNG share card. Remember that scores are reference values and can vary by environment. When you compare under controlled conditions like this, a benchmark becomes a tool for understanding your own device rather than just a way to show off a score.