For the last 3 months I've been working on CapyToolkit - a website with browser tools that run locally, without account needed, and with a strong focus on privacy. A few tools I think are worth highlighting: hardware diagnostics like gamepad drift, input lag and MIDI tester, a SQL Workbench that runs DuckDB on WASM which can be used to preview and query less popular but important DB formats. PII and EXIF scrubbers, offline OCR and redactor, and a WebRTC P2P Tester with no relay. Most tools never touch a server and don't need connection once cached. The few that do use custom Cloudflare workers only where it's required for tool functionality like IndexNow Submitter, or Cert Inspector fetching a cert from URL feature. Website is built with Astro, installable as PWA or via Microsoft Store.
Privacy-wise the only analytics is PostHog, proxied through subdomain. Tool areas and forms are excluded from all tracking, heatmaps or session recordings. PostHog became my choice because it allows me to fully control what I track, and respect users privacy in line with my and website mission.
Please, feel free to test it and drop a feedback, or even request a tool you would like to use there! I would be happy to implement something for you.