Create radar/spider charts as SVG from multi-axis data series.
Radar Chart Generator is one page doing one thing. No account, no settings to sync, no history building up somewhere.
No server sees this. That is a consequence of how the tool is built rather than a policy someone wrote down, which is the version worth trusting.
You will find it under Charts, alongside 7 other tools for the same sort of job.
Supports multiple series, customizable axis labels, and concentric grid rings.
title: Developer Skills
axes: ["JavaScript","CSS","React","Node.js","SQL"]
series: [{"name":"Alice","values":[90,75,85,70,60]},{"name":"Bob","values":[70,80,60,90,85]}]
size: 400
showGrid: true<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 400 400" width="400" height="400"><style>text { font-family: sans-serif; font-size: 11px; fill: #333; }</style><rect width="400" height="400" fill="white"/><text x="200" y="18" text-anchor="middle" font-size="14" font-weight="bold">Developer Skills</text><path d="M 200 170 L 228.5316954888546 190.72949016875157 L 217.6335575687742 224.27050983124843 L 182.3664424312258 224.27050983124843 L 171.4683045111454 190.72949016875157 Z" fill="none" stroke="#ddd" stroke-width="1"/><path d="M 200 140 L 257.0633909777092 181.45898033750316 L 235.2671151375484 248.54101966249686 L 164.7328848624516 248.54101966249686 L 142.93660902229078 181.458980337…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.