12 TOOLS · 100% BROWSER-SIDE · ZERO DATA COLLECTED

The Developer
Utility Belt

Base64, hashing, JSON, JWT, URLs, UUIDs, QR codes, image conversion — everything you reach for daily, in one fast, private suite.

Start with Base64 →
12
Tools Available
0ms
Server Round-Trip
0kb
Data Transmitted
Free Forever
devkit — terminal
base64.decode("SGVsbG8gV29ybGQh")
"Hello World!"

hash.sha256("devkit")
"9b1c35f4..."

uuid.v4()
"f47ac10b-58cc-..."

jwt.decode(token)
{ sub: "user_42", exp: 1735689600 }

Base64 Decode — Most Used Tool
devkit4you.com — Now Live 🎉
12 Tools — 100% Free
Zero Tracking — Zero Signup
Web Crypto API — Hardware-Accelerated Hashing
PWA Ready — Installable & Works Offline
SHA-256 — Industry Standard Hash
JWT Decoder — Inspect Any Token
UUID v4 — Cryptographically Random
QR Codes — Download as PNG
Base64 Decode — Most Used Tool
devkit4you.com — Now Live 🎉
12 Tools — 100% Free
Zero Tracking — Zero Signup
Web Crypto API — Hardware-Accelerated Hashing
PWA Ready — Installable & Works Offline
SHA-256 — Industry Standard Hash
JWT Decoder — Inspect Any Token
UUID v4 — Cryptographically Random
QR Codes — Download as PNG

Everything you need,
nothing you don't.

Every tool runs locally in your browser. No server, no signup, no rate limits.

🔓
MOST USED
Base64 Decode & Encode
The complete Base64 toolkit. Decode strings back to plain text, encode text or files, handle MIME chunking, URL-safe format (Base64URL), multiple charsets. Lightning-fast, fully offline.
#️⃣
POPULAR
Hash Generator
Compute MD5, SHA-1, SHA-256, and SHA-512 hashes from any text. One input, all hashes simultaneously. Click any result to copy.
{}
POPULAR
JSON Formatter
Validate, format with syntax highlighting, minify, and sort keys. Instantly detects and highlights JSON errors with line info.
🔑
JWT
JWT Decoder
Decode and inspect JSON Web Token headers, payloads, and signature claims. Shows expiry status and remaining time at a glance.
🌐
URL Encoder / Decoder
Percent-encode or decode URL components. Handles full URLs and individual query parameter values. Safe for all RFC 3986 characters.
🖼️
Image → Base64
Convert PNG, JPG, GIF, SVG, or WebP to Base64 data URIs. Output as HTML img src, CSS background, or raw Base64 string.
📁
File Encode / Decode
Upload any file to encode to Base64, or paste Base64 data to download the original binary. Works with PDFs, archives, executables — up to 100MB.
🎲
BULK
UUID Generator
Generate cryptographically random UUIDs v4 one at a time or in bulk (up to 1000). Multiple output formats: standard, no dashes, uppercase.
🔲
QR Code Generator
Instantly create QR codes from any text or URL. Adjust error correction level and download as PNG. No third-party APIs.
🔀
Text Diff
Compare two blocks of text and see additions and deletions highlighted line by line. Great for config files, code review, and changelogs.
🎨
Color Converter
Convert between HEX, RGB, and HSL color formats instantly. Visual preview swatch, one-click copy for any format.

Built different.

🔒
Zero Server Contact
Every computation runs natively in your browser. Your data never touches a server, a log, or a database.
Instant Results
No round-trip latency. No loading spinners. Results appear as you type using native browser APIs.
🛠️
No Bloat
Pure HTML, CSS, and JavaScript. No frameworks, no trackers, no analytics, no cookies. Just tools.
♾️
Always Free
No freemium tier, no rate limits, no account needed. Everything is free, forever, for everyone.
📱
Works Everywhere
Fully responsive — desktop, tablet, mobile. Works offline after first load. No app install needed.
⌨️
Command Palette
Press ⌘K from anywhere to instantly jump to any tool.