DK
DevKit4You
22 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 →
22
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 🎉
22 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 🎉
22 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
// all tools

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.
decodeencode utf-8url-safe
#️⃣
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.
md5sha256sha512
{}
POPULAR
JSON Formatter
Validate, format with syntax highlighting, minify, and sort keys. Instantly detects and highlights JSON errors with line info.
jsonformatvalidate
🔑
JWT
JWT Decoder
Decode and inspect JSON Web Token headers, payloads, and signature claims. Shows expiry status and remaining time at a glance.
jwtauthtoken
🌐
URL Encoder / Decoder
Percent-encode or decode URL components. Handles full URLs and individual query parameter values. Safe for all RFC 3986 characters.
urlpercentencode
🖼️
Image → Base64
Convert PNG, JPG, GIF, SVG, or WebP to Base64 data URIs. Output as HTML img src, CSS background, or raw Base64 string.
imagedatauricss
📁
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.
filebinaryupload
🎲
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.
uuidguidrandom
🔲
QR Code Generator
Instantly create QR codes from any text or URL. Adjust error correction level and download as PNG. No third-party APIs.
qrbarcodepng
🔀
Text Diff
Compare two blocks of text and see additions and deletions highlighted line by line. Great for config files, code review, and changelogs.
diffcomparetext
🎨
Color Converter
Convert between HEX, RGB, and HSL color formats instantly. Visual preview swatch, one-click copy for any format.
colorhexrgb
📦
NEW
Number Base Converter
Convert between Binary, Octal, Decimal and Hex instantly. Custom bases 2–36. Bit-width representations for 8/16/32-bit.
binaryhexoctal
🔐
NEW
Password Generator
Cryptographically secure passwords via crypto.getRandomValues(). Custom length & charset, strength entropy meter, bulk generation.
securitycryptorandom
🔗
NEW
URL Parser & Builder
Break any URL into protocol, host, path, query params and fragment. Edit any part and rebuild the full URL live. Great for API debugging.
urlqueryparse
📊
NEW
JSON ↔ CSV
Convert JSON arrays to CSV and back. Live table preview. Auto type inference. Custom delimiter — comma, tab, semicolon or pipe.
jsoncsvconvert
📝
NEW
Regex Tester
Test regular expressions live with real-time match highlighting, capture group extraction, replace mode, and 6 pre-built samples. JavaScript engine.
regexmatchreplace
🕐
NEW
Timestamp Converter
Convert Unix epoch timestamps to human-readable dates and back. UTC, local time, ISO 8601, RFC 2822, relative time. Live clock. Auto-detects seconds vs ms.
unixepochdate
📄
NEW
Markdown Previewer
Live Markdown editor with side-by-side preview. GFM support — tables, code blocks, task lists. Export to HTML. Sync scroll. Split, editor, or preview mode.
markdowngfmhtml
⏱️
NEW
Cron Expression Builder
Easily create and understand cron expressions with a visual builder. Generate schedules for tasks, automate jobs, and validate cron syntax in real-time.
cronshedulerautomation
👨🏼‍💻
BEST
CSS Gradient Builder
Create beautiful CSS gradients with a live visual editor. Customize colors, angles, and gradient types, then copy clean CSS code instantly.
CSSgradientdesign
🔢
BEST
Number Formatter
Format numbers instantly with support for locale, currency, percentages, and scientific notation. Perfect for developers, finance, and data analysis.
numberformattercurrency
// philosophy

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.