Factor any number into its prime factors.
Prime Factorization loads once and then runs on its own. Close the tab and there is nothing left behind, on the machine or anywhere else.
Everything after the first page load is local. Pull the network cable mid-edit and the tool carries on as though nothing happened.
You will find it under Everyday sums, alongside 13 other tools for the same sort of job.
Shows complete prime decomposition with exponent notation.
360
360 = 2^3 × 3^2 × 5
Yes. It is JavaScript running in this tab, so once the page has loaded it needs nothing further from the network. Put the machine in flight mode and it carries on. Nothing you do here is sent anywhere, because there is nowhere for it to go.
No. Reload the page and it starts from nothing. There is no account, no saved state and no cookie holding your last session. That is a deliberate trade: it cannot lose your data because it never keeps any.
Timing comes from performance.now(), the high resolution clock the browser provides, rather than from setInterval, which drifts by a few milliseconds every tick and compounds over minutes. What can still shift things is the browser throttling a tab in the background, so leave it visible if the timing matters.
Where a sound makes sense, it is generated with the Web Audio API rather than loaded as a file, so there is nothing to download and nothing to block. Browsers refuse to start audio until you have interacted with the page, which is why the first press is what switches it on.
Yes. The controls are sized for touch and the layout collapses to one column on a narrow screen. Bear in mind that a phone locking its screen will suspend the page, and timing stops with it.