CPU benchmark online. How fast your processor is, measured.
How fast is your processor? Run every core from this browser and get its peak and sustained speed in millions of operations per second. Nothing to install: the CPU stage is the first 60 seconds of the free 3 minute run.
Illustrative run. Your own cores draw their own.
Load
Every logical core
Unit
M ops/s, all threads
CPU stage
60 s, 150 s on Deep
Reports
Peak, sustained, boost step
A speed test, counted, not estimated.
The CPU stage counts the work every core actually finished and turns it into a rate. Nothing in the figure is a guess about operations the code did not run.
- One worker per core
- A Web Worker runs on every logical core the browser reports, up to 32, each repeating the same floating-point kernel compiled to WebAssembly. Each worker checks the kernel's answer before its work is counted.
- Counted every quarter second
- Each worker reports how many kernel iterations it finished and when, and the work is placed into 250 ms windows. The speed is a series of about 240 points across the 60 second stage, not one number.
- Warm-up left out, boost kept
- The first 1.5 seconds cover worker start-up and are dropped. The boost that follows is kept, because how long a processor holds its top speed is part of the answer.
- Longer runs for a settled speed
- The Deep run holds the CPU for two and a half minutes and the Extended run for 10 minutes, so the sustained figure comes from a processor that has reached its own long-term limit.
What the benchmark reports about your processor.
Every figure below is printed in the report's CPU table, free. The unit is millions of kernel iterations per second across all threads, written M ops/s.
Peak
The best one-second level after warm-up: how fast the processor runs while its boost lasts.
Sustained
The mean over the whole stage after warm-up, with a 95% interval from the run's own spread. This is the speed to compare between runs and between machines in the same browser.
Boost step and decay
The boost step is the best second in the first 10 s against the level the processor settled to; decay is that settled level against the closing fifth. A drop inside the run's own noise is counted as 0.
Threads and consistency
How many threads were loaded, and how evenly the work arrived, out of 100. Uneven work usually means another program was sharing the cores.
Illustrative run. Your own cores draw their own.
Hardware
What it needs. Three tiers, no fine print.
Minimum
Any recent browser
Chrome, Edge, Firefox or Safari on a laptop or desktop completes the CPU stage.
Recommended
Plugged in, same browser each time
The browser and the power source both move the figure, so compare runs made the same way with other apps closed.
Optimal
The Extended run
16.5 minutes with a 10 minute CPU stage, for a sustained figure well past any boost window.
In short
CPU benchmark: the answer first
A CPU benchmark online tells you how fast your processor is. This one runs a WebAssembly kernel on every logical core for 60 seconds, counts the work finished every quarter second, and reports the peak speed while the boost lasts and the sustained speed across the stage, both in millions of operations per second (M ops/s).
Reading your result
- Sustained is the headline
- Peak is what the processor manages for its first few seconds; sustained is the mean across the stage. The sustained figure is the one that decides how a long compile, export or game feels.
- A boost step is expected
- Many processors run fast for a few seconds and then settle. The report prints that drop as the boost step, with the second it ended, and keeps it out of decay, so an early step is not counted as a fault.
- Compare in the same browser
- The unit is the kernel's own, so compare runs in the same browser, plugged in, with other apps closed. A different browser, battery power or a busy machine moves the figure.
What good looks like
The ranges, before you run it.
Overall score (provisional bands)
- 85 to 100
- Excellent (provisional)
- Fast, and it keeps its speed under long work.
- 70 to 84
- Strong (provisional)
- Comfortable for demanding work.
- 55 to 69
- Good (provisional)
- Fine for everyday and moderate work.
- 40 to 54
- Modest (provisional)
- Everyday tasks; heavy work will feel slow.
- Below 40
- Limited (provisional)
- Struggles with sustained work.
Slowdown under long work
- Under 8%
- Holds its speed
- Little lost over the run.
- 8% to 15%
- Normal
- Common on laptops and compact PCs.
- 15% to 30%
- Noticeable
- Long tasks run clearly slower than short ones.
- 30% or more
- Worth checking
- Often heat, dust or a low power limit.
Processor steadiness
- 90 or more
- Steady
- Work is delivered evenly.
- 75 to 89
- Some unevenness
- Small dips, often background apps.
- Below 75
- Uneven
- Something else may be competing for the processor.
What a browser cannot see
The honest limits, and where to look instead.
- How full your memory isA web page cannot see how much memory is in use. If the machine slows down with many apps or tabs open, check it directly.
- On a MacActivity Monitor, Memory tab: Memory Pressure at the bottom. Yellow or red means memory is the limit.On WindowsTask Manager (Ctrl+Shift+Esc), Performance, Memory. Above about 85% in use while you work means memory is the limit.
- Temperatures and fan speedNo browser can read a temperature sensor, so heat shows here only as speed lost over time.
- On a MacA free app such as Stats shows temperatures and fan speed.On WindowsHWiNFO, or your laptop maker's own app.
- Storage speed and healthOpening apps and files depends on the drive, which this test does not touch.
- On a MacDisk Utility, then First Aid on your main drive.On WindowsCrystalDiskInfo shows the drive's health status.
Questions
CPU benchmark, answered
- How do I benchmark my CPU online?
- Start the free test on this page and keep the tab in front. The CPU stage loads every core for 60 seconds, and the report gives the peak and sustained speed in M ops/s; the rest of the 3 minute run tests memory and graphics.
- Does it give a single-core and a multi-core score?
- It measures all cores together. The CPU stage runs one worker per logical core and reports the total across every thread, with the thread count beside it, and the live readout shows the per-thread average as well. There is no separate single-core run, so there is no single-core score. If workers cannot start, the stage runs on one thread and the report labels its figures single-core.
- What does a result look like?
- On the Core i5-1245U laptop we validate on (12 threads, Chrome, plugged in, measurement revision 2026.09.18), six Standard runs read 212 to 232 M ops/s sustained and 262 to 309 M ops/s peak, with a boost step of 19 to 27% and no settled decay. That is one laptop, a reference point rather than a scale.
- Can I compare the number with Cinebench or Geekbench?
- No. Cinebench and Geekbench are native apps that score their own workloads in points, so their scores and M ops/s are different units. Compare this figure with your own earlier runs and with other SystemCheck runs in the same browser.
- Why is a browser benchmark lower than a native one?
- The page runs inside the browser's own scheduling and security limits, so the absolute figure is a floor. What it measures well is the same machine against itself: the same browser, the same power source and the same apps closed give a sustained figure that repeats closely.
- What is the difference between a CPU benchmark and a CPU stress test?
- Here they read the same stage for different answers. The benchmark reading is how fast the processor is: peak and sustained M ops/s. The stress test reading is whether it holds that speed: the slowdown, its shape and its steadiness. The CPU stability test is a third question, whether every core computes correctly.