Dev Tools: JWT, JSON, Regex Live

6 developer tools. 1 app. 0 data collected. Dev Tools is a fast, offline-first toolkit built for Android developers, backend engineers, security researchers, and CS students who need to test a regex, decode a JWT, or format a JSON blob without opening a laptop — or trusting a browser tool with their data. Every single computation happens on your device. Nothing you paste, type, or decode is ever sent to a server. There's no account, no signup, no internet permission required to use any tool, and no ads anywhere in the app. WHAT'S INSIDE • Regex Tester — Real-time pattern matching with live highlighting, capture group inspection, flag toggles (case-insensitive, multiline, dot-all), and instant syntax error feedback. • JWT Decoder & Inspector — Paste any JSON Web Token and instantly see the decoded header, payload, and claims — including human-readable expiry (exp), issued-at (iat), and not-before (nbf) timestamps. Signature is shown but never verified or transmitted anywhere. • JSON Formatter & Tree View — Pretty-print or minify JSON with 2- or 4-space indent, get precise line/column error locations for invalid JSON, and browse results in a collapsible tree view. • Base64 Encoder/Decoder — Encode or decode text instantly, with URL-safe mode and automatic direction detection. • Hash Generator — Generate MD5, SHA-1, SHA-256, and SHA-512 hashes simultaneously as you type, with one-tap copy and upper/lowercase hex toggle. • URL Encoder/Decoder — Encode or decode full URLs, individual components, or query parameters with real-time diff highlighting of changed characters. WHY DEVELOPERS SWITCH FROM BROWSER TOOLS Bookmark tabs for jwt.io, regex101, or an online JSON formatter all share the same problem: your data — API tokens, production JSON payloads, customer identifiers — leaves your device and touches a server you don't control. Dev Tools runs 100% locally, works with airplane mode on, opens in under a second, and keeps six separate bookmarks out of your browser for good. BUILT FOR ANDROID, NOT PORTED FROM THE WEB • Full Material You dynamic color support — the app matches your wallpaper on Android 12+ • Complete dark mode, tuned per tool for readability • Instant clipboard copy on every result • Clean, modern Material Expressive interface — no clutter, no dated Holo-era UI PRIVACY BY DESIGN, NOT AS AN AFTERTHOUGHT No account required. No data leaves your phone during tool use. Anonymous, aggregated crash and usage analytics (via Firebase) help fix bugs and prioritize features — never your input text, tokens, or decoded content. Full details in our privacy policy, linked below. 100% FREE — FOREVER Every tool listed above is completely free, with no locked features, no paywalls, and no forced trial. If Dev Tools saves you time, an entirely optional one-time tip (from a coffee to a generous "wow, really?") is available on the Support page — but the app is fully functional whether you ever tip or not. WHO IT'S FOR • Android & mobile developers debugging API responses on the go • Backend & web developers who need a quick JSON/URL check away from their desk • Security engineers inspecting JWT claims or verifying hash values • QA engineers, freelancers, and CS students learning encoding and pattern matching Six tools. Zero ads. Zero tracking of your data. Zero excuses to keep six browser tabs open. Download Dev Tools and keep your JWTs, JSON, and regex testing exactly where they belong — on your device.