Cog
The offline developer toolbox for iOS.
19 tools you reach for every day — JSON, Base64, JWT, hashes, regex, diff, UUID and more. One fast app. No account, no tracking, entirely on-device.
🔒 Zero network calls · nothing leaves your phone
The offline developer toolbox for iOS.
19 tools you reach for every day — JSON, Base64, JWT, hashes, regex, diff, UUID and more. One fast app. No account, no tracking, entirely on-device.
A searchable grid of focused tools with live results. Twelve are free; the Pro power pack is a one-time purchase.
Pretty-print, minify, sort keys.
Encode & decode, incl. Base64URL.
Percent-encode and HTML entities.
Inspect header & claims (decode only).
MD5, SHA-1, SHA-256, SHA-512.
Generate v4 identifiers.
Unix timestamps ↔ dates.
camelCase, snake_case, kebab, slugs.
HEX ↔ RGB ↔ HSL with a live swatch.
Break a URL into its components.
Live match highlighting & capture groups.
Line-by-line comparison.
Keyed hashing with your secret.
Understand any schedule.
ULID, NanoID, UUID v7.
Generators for real work.
Search, tap, paste, copy. Live results as you type — plus a Home Screen widget and a Share Extension.
Cog makes zero network calls. Nothing you paste ever leaves your phone. No analytics, no ads, no accounts — and one honest one-time price for Pro.
Read the privacy policy