JPKCom Developer Tools by

JPKCom Developer Tools
Code & Text Tools
Beautify Cheat Sheets Coder Compiler Convertor PRO CSV Editor JSON Editor Lorem Ipsum Markdown Editor Playground Regex Debugger Source Viewer WP Code Generator WYSIWYG Editor
Design & Graphics
Colors Fonts Geopattern Graphic Editor PDF Tools Periodensystem (PSE) Placeholder Service Trianglify UI
AI & SEO
llms.txt Generator Meta Tags Generator robots.txt & Sitemap SEO & GEO Analyzer
Security & Utilities
Cryptor (AES-256) DNS, SSL, Redirect & URL Cron Job Helper Docker/Podman Composer IP Tools Generator Hash Generator Mail Header Analyzer PKI Viewer SSH Proxy Info Tools QR Code Time Converter UUID Generator
About
JPKCom Developer Tools

Free online tools for web developers and designers.

40 Tools available.

A curated collection of 40 free online tools for web developers and designers. All tools run directly in the browser — no registration, no tracking, no data stored on our servers.

Code & Text Tools

Editors, formatters, and debuggers for working with code and text.

Beautify

Beautify, format, and deobfuscate JavaScript, CSS, and HTML code. Make JSON and JSONP readable with proper indentation.

Cheat Sheets

215 cheat sheets for CLI tools, package managers, and web development. Search commands, copy with one click, and syntax-highlighted examples.

Coder

Encode and decode HTML entities, URLs, Base64, JSON strings, JSON Web Tokens (JWT), and Data URIs. Multi-format encoding and decoding tool.

Compiler

Compile SASS/SCSS to CSS, beautify and minify HTML, JavaScript, and CSS. Split-view editors with file upload, download, and clipboard support.

Convertor PRO

Convert between HTML/XML, JavaScript and CSS escapes, Unicode, UTF-8, UTF-16, hexadecimal, decimal, URI encodings, and data formats (YAML, JSON, TOML, XML).

CSV Editor

Open, edit, and export CSV files online. Spreadsheet editor with delimiter auto-detection, CSV and JSON export, and browser storage.

JSON Editor

Modern JSON editor with tree, table, and code views. Format, validate, repair, transform, and query JSON data online.

Lorem Ipsum

Generate placeholder text in Latin, English, or German. Choose length by paragraphs, words, or characters. Plain text and Markdown output.

Markdown Editor

Write Markdown with live preview, synchronized scrolling, GitHub Flavored Markdown support, and export to HTML.

Playground

Interactive HTML, CSS/SCSS and JavaScript editor with live preview, Bootstrap/jQuery asset toggles, named save slots, and export/import.

Regex Debugger

Test and debug regular expressions with real-time matching, flag support, named capture groups, and an integrated cheat sheet.

Source Viewer

Code editor with syntax highlighting for 100+ languages, code beautification, URL loading, and HTML to Markdown conversion.

WP Code Generator

Generate WordPress boilerplate code for plugins, themes, blocks, hooks, CPTs, taxonomies, meta fields, settings pages, and more.

WYSIWYG Editor

Rich text editor based on TinyMCE with HTML5 local storage. Create and edit HTML content visually in the browser.

Design & Graphics

Color pickers, font tools, image editors, and pattern generators.

Colors

Color picker and image color scheme generator. Extract color palettes from images with dark mode support.

Fonts

Preview and compare base fonts, Google Fonts, and custom font files in real-time with adjustable size and weight.

GeoPattern

Generate beautiful geometric SVG patterns from any text string. Choose from multiple pattern types and color schemes.

Graphic Editor

HTML5 image editor for cropping, scaling, and format conversion. Export to PNG, JPEG, WebP, and AVIF. Fully client-side.

PDF Tools

Create, view, edit, merge, and split PDF files in the browser. Annotate, highlight, draw, fill forms, and extract text. Powered by pdfmake, Mozilla PDF.js, and pdf-lib.

Periodic Table (PSE)

Interactive periodic table of all 118 elements with category filter, search, and detailed element data including states, electron configurations, and thermodynamic properties in English and German.

Placeholder Generator

Generate custom placeholder images with configurable dimensions, colors, and text. Presets for social media and web banners.

Trianglify UI

Generate algorithmically created low-poly triangle background patterns with customizable colors and complexity.

AI & SEO

Tools for AI context, metadata, and search engine optimisation.

llms.txt Generator

Generate llms.txt files for your website. The proposed standard helps AI language models understand your content. Includes examples, best practices, and format reference.

Meta Tags Generator

Generate essential, Open Graph, Twitter/X Card, mobile, security, performance, and structured data (JSON-LD) meta tags with live preview and one-click copy.

robots.txt & Sitemap

Generate robots.txt (with User-agent rules, Disallow/Allow, Crawl-delay, AI bot blocking) and sitemap.xml (URLs with lastmod, changefreq, priority) with live preview.

SEO & GEO Analyzer

Comprehensive SEO & GEO analysis: HTTP headers, SSL certificates, redirect chains, meta tags, links, images, structured data, content analysis, accessibility, robots.txt, AI readiness scoring, and more.

Security & Utilities

Encryption, hashing, network diagnostics, and general-purpose generators.

Cryptor

AES-256-bit encryption and decryption of text messages. Client-side encryption with password protection for maximum privacy.

DNS, SSL, Redirect & URL

Check DNS records (incl. DKIM), analyze SSL certificates, trace HTTP redirects, parse URLs, and generate SPF records.

Cron Job Helper

Visual cron expression builder with presets and next-run preview. Configure web crons (curl/wget), and get setup guides for WordPress, TYPO3, Drupal, Laravel, Docker, and DDEV.

Docker / Podman Composer

Convert docker run and podman run commands to Docker Compose YAML and back. Supports ports, volumes, environment, networks, healthchecks, and more.

IP Tools

IPv4 & IPv6 utilities: detect your IP, calculate subnets, convert IP formats, generate IPv6 ULA prefixes, calculate IP ranges, and browse reference tables.

Generator

Generate passwords, salt & security keys, BCrypt/Argon2 hashes, and TOTP one-time passwords with QR code.

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-384, SHA-512, SHA-3, and RIPEMD-160 hashes with HMAC support.

Info Tools

Display browser info, HTTP headers, IP address, installed plugins, and HTML5/CSS3 capabilities.

Mail Header Analyzer

Parse and visualize email headers (RFC 5322). Trace delivery routes, check SPF/DKIM/DMARC authentication, and search all header fields.

PKI Viewer

Inspect X.509 certificates, PKCS#7/P7M, PKCS#12/PFX, CSR and keys. View details, check validity, compute fingerprints, and extract P7M content.

SSH Proxy

Generate SSH tunnel, SOCKS proxy, and port forwarding commands. SSH config, proxy settings, management scripts, autostart configs, and troubleshooting for Linux, macOS, Windows, BSD, and WSL.

QR Code Generator

Generate QR codes from any text, URL, or data with customizable size and error correction levels.

Time Converter

View current international time formats and convert Unix timestamps to human-readable dates and vice versa.

UUID Generator

Generate RFC 4122 compliant Universally Unique Identifiers (UUIDs) in various formats.