Web Probes is part of DevStudio — a free, in-browser collection of developer utilities that work without sign-up, installation, or any backend service. Redirect trace, header dump, security audit, HTTP/2 + HTTP/3 + WebSocket sniff, URL compare and link checker, all running entirely on your device. Because the page never uploads what you paste, you can run sensitive payloads, configuration files, secrets, or production data through it with confidence: nothing leaves your browser tab. Use Web Probes for ad-hoc debugging, code review, log triage, release prep, learning a new format, or as a quick scratchpad while you build. If you use this tool a lot, pair it with DNS Toolkit, Mail Diagnostics, Domain Diagnostics, and the rest of the DevStudio toolkit for related developer workflows.