Local-first tools
Most SpecWhale tools run entirely in your browser. Calculators and converters compute results on your device using JavaScript; nothing you type into them is sent to a SpecWhale server. File tools (image resizing, checksums, text/PDF utilities) process files locally in your browser as well -- your files are never uploaded anywhere by these tools.
Tools that call external APIs
Two tools -- public holidays and weather -- call free, keyless public APIs (Nager.Date and Open-Meteo) directly from your browser to fetch current public data. These requests go straight from your browser to that public API; no SpecWhale server sits in the middle. Country Lookup is a local browser reference.
What's stored in your browser
Favorites, recently-visited tools, and your dark/light theme preference are stored using your browser's localStorage, on your device only. Clearing your browser data removes these preferences.
Analytics
The production site may use privacy-friendly, aggregate analytics (page views and general usage patterns) to understand which tools are useful, without individually identifying visitors or relying on invasive tracking cookies.
Advertising
SpecWhale uses Monetag In-Page Push and Vignette advertising. These ads appear within the website and do not request browser notification permission. Monetag may process browser and device information according to its own policies. Avoid entering sensitive secrets (passwords, private keys, financial account numbers) into any website's tools unless you understand exactly how that specific tool handles them.