inputprobe DPI Test's answer

PC gamers dialing in sensitivity who want to know their real DPI rather than the nominal number on the box, mouse enthusiasts (the r/MouseReview crowd) comparing sensors and verifying units, and anyone troubleshooting a mouse that "feels wrong", since a few percent of unit-to-unit sensor variance is normal and measurable. More broadly, anyone who prefers a measurement with a stated error band over a confident guess.

inputprobe DPI Test's answer

Two things. First, it measures instead of guessing: a browser cannot ask a mouse for its DPI, so the test divides raw movement counts by the length of an object that is exact by international standard, every bank card on earth is 85.60 mm long (ISO/IEC 7810), and paper sizes are fixed by ISO 216. Second, it publishes its own error bars. The accuracy bands shown next to your result were measured over 51 complete runs on real hardware (results on A4 stay within ~3% of each other, on a bank card within ~6%), and when a capture can't support a number, the test refuses to print one and tells you why, rather than averaging a mess into a confident-looking figure.

inputprobe DPI Test's answer

Most online mouse testers measure your monitor, not your mouse: they count one movement per drawn frame, so results are quietly capped by your display's refresh rate. inputprobe reads the individual device reports with their own timestamps, before that distortion happens. It also handles the errors other testers ignore: it detects OS pointer acceleration instead of blaming your mouse, uses displacement so your drag doesn't need to be straight, and includes an alignment check that solves for your placement error, the one mistake repeatability checks structurally cannot see. And everything runs locally in your browser: no account, no upload, no tracking.

inputprobe DPI Test's answer

I tested my own mouse on the popular online testers and got answers that were confidently wrong, most of them were really measuring my monitor's refresh rate. So I built a set of testers around one rule: a verdict must quote the evidence it's based on, and when the evidence isn't good enough, the tool refuses to print a number. That meant doing the unglamorous part: running the DPI method 51 times across two mice to measure how accurate it actually is, publishing those bands next to every result, and writing up the full methodology (including what has not been validated yet) at inputprobe.com/methodology/.

inputprobe DPI Test's answer

Plain-vanilla web platform, no frameworks: the measurement engine is dependency-free JavaScript ES modules. The site is static HTML generated by a small Python build (Jinja2 + Markdown), served from Cloudflare's edge. There is no backend at all, every measurement runs entirely in the browser and nothing is uploaded.

inputprobe DPI Test's answer

None to list, it's a free tool with no accounts and no tracking, so we genuinely don't know who uses it, and we prefer it that way.