Cog - Dev Toolbox

Cog is a fast, offline toolbox for developers — a whole shelf of the little utilities you reach for every day, in one clean app. No account. No network. No tracking. Everything runs on your device. Stop pasting sensitive tokens and payloads into random websites. Cog does it all locally. FREE TOOLS • JSON — pretty-print, minify, sort keys • Base64 — encode & decode • URL encode / decode • HTML entities — escape & unescape • JWT decode — inspect header & claims (decode only) • Hash — MD5, SHA-1, SHA-256, SHA-512 • UUID — generate v4 • Epoch time — convert Unix timestamps ↔ dates • Case convert — camelCase, snake_case, kebab, PascalCase, CONSTANT • Slugify — clean URL-safe slugs • Color — HEX ↔ RGB ↔ HSL with a live swatch • URL parse — break a URL into its components COG PRO (one-time purchase — yours forever) • Regex tester — live match highlighting & capture groups • Diff — line-by-line comparison • HMAC — keyed hashing with your secret • Cron explainer — understand any schedule • ID Generator — ULID, NanoID, UUID v7 • Password generator — strong, configurable • Lorem Ipsum — placeholder text BUILT FOR SPEED • Search every tool instantly • Favorites for the tools you use most • Live results as you type • Home Screen widget & Share Extension — run a tool on selected text from any app • History of your recent conversions, stored locally PRIVATE BY DESIGN Cog makes zero network calls. Nothing you paste ever leaves your phone. No analytics, no ads, no accounts. One honest price for Pro. No subscription.