Free tools
Small tools for people who test things
No account, no email gate, no upload. Everything below is useful whether or not you ever use ZeusQA, and the tools run entirely in your browser.
Viewport size reference
Live CSS viewport, DPR, safe-area insets and pointer type, plus the real viewport of 100+ devices.
Selector brittleness checker
Paste selectors or a whole spec file. Get a score per selector and the reason each one will break.
Test prompt builder
Compose a browser-agent test prompt, an equivalent for any agent, or a manual test plan.
Lockfile vulnerability checker
Drop a lockfile or manifest from npm, PyPI, Go, Cargo, Composer or RubyGems. See every known advisory, what is exploited and the fix.
Latest CVEs feed
This week's Critical and High CVEs, what CISA added to KEV and the EPSS odds of each being exploited.
Try it on your own site
Paste a URL, describe the flow in plain English, and watch a real browser do it. Three runs free, no card.