How many CPU cores does my browser report?
See how many logical CPU cores your browser reports through hardwareConcurrency. Detected live in your browser, nothing uploaded.
The number of logical CPU cores your browser reports is shown above, from the hardwareConcurrency value. It reflects logical processors, so a chip with hardware multithreading may report double its physical core count. It tells a page how many parallel workers it can reasonably spin up.
Web apps use this to decide how many background threads (Web Workers) to create for heavy tasks like image processing, compression or parsing, so the work spreads across cores instead of freezing the interface. Ask for too many workers on a small device and you slow things down; too few on a big one wastes capacity.
The figure is a hint, not a guarantee of exclusive access. Your cores are shared with everything else running, and some browsers cap or round the number, so treat it as an upper bound for parallelism rather than a precise hardware spec.
What you should know
Why sites collect it
Performance-sensitive sites read the core count to size their thread pools, parallelising heavy work to keep the interface smooth. Analytics may record it as a rough device-class indicator.
Privacy implications
Core count is a moderate fingerprinting signal. Common values (4, 8, 16) are widely shared, but the number still adds entropy, and unusual counts stand out. It is often combined with device memory and GPU to characterise a device.
How to change or hide it
There is no user-facing setting to change the reported core count. Privacy browsers may cap or normalise it to a common value to reduce distinctiveness. Otherwise it reflects your real logical processor count.
Frequently asked questions
Why does my core count seem too high?
It reports logical processors, so hardware multithreading can make a chip appear to have twice its physical cores. An 8-core chip with two threads each may report 16.
Does a high core count make websites faster?
Only if a site is built to use multiple workers. Many are single-threaded, so extra cores help heavy web apps but not ordinary pages.