IPv4 subnet mask calculator. CIDR notation. Dotted mask. Host ranges. Broadcast. Binary visualisation.

Cryptographically random passwords and passphrases. Uses window.crypto — not Math.random(). Nothing leaves your browser.

SHA-256, SHA-512, SHA-1 for text and files. File integrity verification. Web Crypto API. Drag and drop.

Digital presence scanner. Public IP, geolocation, browser, OS, GPU, WebRTC leak check, ad blocker detection, permissions audit, timezone/IP mismatch, canvas fingerprint. DON'T PANIC.

Base64, Hex, URL encoding and decoding. JWT decoder with expiry highlighting and claims display.

Unix epoch ↔ human-readable. Live clock. ISO 8601. Time difference calculator. Auto-detects seconds vs milliseconds.

Visual cron expression builder. 18 presets. Next-run preview. Paste and parse any expression. Human-readable description.

Live regex testing with match highlighting. Named groups. Flags. 12 common patterns. Zero ads, zero tracking.

Serious race predictor (elevation, pacing discipline, temperature, negative splits) and Beer/Wine Marathon chaos engine. Calibrated on real data: Big Sur, Chester × 3, Medoc, Belgium Beer × 5.

The Hitchhiker's Guide to the Command Line. Ubuntu + PowerShell. Searchable. Toggle between OS.