# DevHandy — Developer Tools & Utilities > DevHandy (https://devhandy.io) is a fast, privacy-first developer utility suite running 100% client-side in the browser. Zero telemetry, zero logins, zero data retention. DevHandy provides web developers, engineers, and technical SEO specialists with browser-based formatters, validators, generators, encoders, and converters. All data is processed locally using web standards and Web Crypto APIs; no code, secrets, tokens, or personal payloads are ever sent to remote servers. - [Full LLM Documentation](https://devhandy.io/llms-full.txt): Comprehensive documentation of all tools, schemas, and specifications for LLMs and AI coding assistants. - [XML Sitemap](https://devhandy.io/sitemap.xml): Standard XML sitemap index. - [Robots.txt](https://devhandy.io/robots.txt): Machine crawler access directives. ## Core Navigation - [Home](https://devhandy.io/): Central dashboard and instant search launcher for developer utilities. - [Tools Directory](https://devhandy.io/tools): Complete filterable catalog of all developer tools. - [Popular Tools](https://devhandy.io/popular): Curated selection of high-frequency tools like JSON Formatter, JWT Decoder, and Regex Tester. - [Categories](https://devhandy.io/categories): Organized category view of all tools. - [Saved Favorites](https://devhandy.io/favorites): User's locally bookmarked developer tools. - [HTML & XML Sitemap Index](https://devhandy.io/sitemap): Hierarchical tree map, XML sitemap viewer, and LLM sitemap inspector. - [About DevHandy](https://devhandy.io/about): Mission statement, privacy guarantees, browser execution architecture, and contact information. - [Privacy Policy](https://devhandy.io/privacy): Zero-telemetry commitment and client-side processing guarantees. - [Terms of Service](https://devhandy.io/terms): Permitted usage terms for free online utilities. ## JSON & Data Tools - [JSON Formatter](https://devhandy.io/tools/json-formatter): Pretty-print, format, indent, and validate JSON objects with customizable spacing. - [JSON Validator](https://devhandy.io/tools/json-validator): Strict RFC 8259 syntax checker with line-by-line error markers. - [JSON Minifier](https://devhandy.io/tools/json-minifier): Strip whitespace, line breaks, and indentation for minimal API payload sizes. - [JSON to TypeScript](https://devhandy.io/tools/json-to-typescript): Infer and generate clean TypeScript interfaces and type definitions from JSON structures. - [JSON to YAML](https://devhandy.io/tools/json-to-yaml): Convert JSON payloads directly into clean YAML documents for configs and CI/CD. - [YAML to JSON Converter](https://devhandy.io/tools/yaml-to-json): Parse and convert YAML configurations into standard formatted JSON. - [JSON to CSV Converter](https://devhandy.io/tools/json-to-csv): Flatten and export JSON object arrays into downloadable tabular CSV spreadsheets. - [CSV to JSON Converter](https://devhandy.io/tools/csv-to-json): Parse CSV/TSV spreadsheets into structured JSON arrays or key-value records. ## Web Development & Formatters - [HTML Formatter](https://devhandy.io/tools/html-formatter): Clean and indent nested HTML markup. - [CSS Formatter](https://devhandy.io/tools/css-formatter): Organize and beautify CSS stylesheets, rules, and selectors. - [JavaScript Formatter](https://devhandy.io/tools/javascript-formatter): Format and standardize JavaScript and ECMAScript source code. - [HTML Minifier](https://devhandy.io/tools/html-minifier): Remove redundant whitespace, newlines, and comments to optimize HTML delivery. - [CSS Minifier](https://devhandy.io/tools/css-minifier): Minify CSS rules and strip comments to maximize rendering speed. - [JavaScript Minifier](https://devhandy.io/tools/javascript-minifier): Compress JS payloads to reduce script bundle footprint. - [URL Encoder / Decoder](https://devhandy.io/tools/url-encoder-decoder): Bidirectional tool to encode or decode URL query strings and URI components. - [URL Encoder](https://devhandy.io/tools/url-encoder): Percent-encode query parameters and paths for safe network requests. - [URL Decoder](https://devhandy.io/tools/url-decoder): Decode percent-encoded strings back to standard UTF-8 text. - [HTML Entity Encoder](https://devhandy.io/tools/html-entity-encoder): Escape special characters into safe HTML entities to prevent XSS vulnerabilities. - [HTML Entity Decoder](https://devhandy.io/tools/html-entity-decoder): Decode HTML entities back to raw text characters. ## SEO & AI Crawlers - [LLM Sitemap Generator](https://devhandy.io/tools/llm-sitemap-generator): Generate llms.txt, llms-full.txt, and AI-optimized sitemaps for ChatGPT, Claude, Cursor, and Perplexity. - [XML Sitemap Generator](https://devhandy.io/tools/xml-sitemap-generator): Generate standard sitemaps.org XML sitemaps with priority and frequency tags. - [Robots.txt Generator](https://devhandy.io/tools/robots-txt-generator): Configure crawler rules and sitemap directives for Googlebot, Bingbot, and AI bots. - [Meta Tag Generator](https://devhandy.io/tools/meta-tag-generator): Generate complete search metadata, Open Graph tags, and Twitter Cards. - [Open Graph Generator](https://devhandy.io/tools/open-graph-generator): Create Facebook, LinkedIn, and social media share preview tags. - [Twitter/X Card Generator](https://devhandy.io/tools/twitter-card-generator): Generate Twitter summary and summary_large_image card tags. - [Schema Markup Generator](https://devhandy.io/tools/schema-markup-generator): Generate Google Rich Snippet JSON-LD structured data schemas. - [Schema Generator](https://devhandy.io/tools/schema-generator): Create JSON-LD markup for Organizations, WebSites, and Products. - [FAQ Schema Generator](https://devhandy.io/tools/faq-schema-generator): Generate FAQPage schema markup to trigger interactive Google accordion results. - [Breadcrumb Schema Generator](https://devhandy.io/tools/breadcrumb-schema-generator): Create BreadcrumbList JSON-LD markup for navigational search snippets. - [Article Schema Generator](https://devhandy.io/tools/article-schema-generator): Generate NewsArticle and BlogPosting JSON-LD for rich cards. - [Canonical Tag Generator](https://devhandy.io/tools/canonical-tag-generator): Generate rel="canonical" tags to prevent duplicate content indexing. - [Hreflang Generator](https://devhandy.io/tools/hreflang-generator): Create international and multilingual hreflang tag configurations. - [SERP Snippet Preview](https://devhandy.io/tools/serp-snippet-preview): Real-time visual simulator for desktop and mobile Google search results. ## Security & Cryptography - [JWT Decoder](https://devhandy.io/tools/jwt-decoder): Inspect JWT header, claims, payload, and expiration without sending secrets to any server. - [Base64 Encoder / Decoder](https://devhandy.io/tools/base64-encoder-decoder): Bidirectional conversion between plain text and Base64 encoding. - [Base64 Encoder](https://devhandy.io/tools/base64-encoder): Convert plaintext or UTF-8 strings into standard Base64 representation. - [Base64 Decoder](https://devhandy.io/tools/base64-decoder): Decode Base64 strings back into original UTF-8 text. - [Hash Generator](https://devhandy.io/tools/hash-generator): Compute SHA-256, SHA-512, SHA-384, SHA-1, and MD5 cryptographic checksum digests. - [UUID Generator](https://devhandy.io/tools/uuid-generator): Generate cryptographically secure RFC 4122 v4 unique identifiers (GUIDs). - [Random String Generator](https://devhandy.io/tools/random-string-generator): Generate high-entropy random strings, API test keys, and secrets. - [Password Generator](https://devhandy.io/tools/password-generator): Generate high-entropy, customizable, breach-resistant passwords. - [SSL Certificate Checker](https://devhandy.io/tools/ssl-certificate-checker): Inspect domain SSL/TLS certificates, expiry dates, trust chains, SANs, and decode PEM certificates. ## Developer Utilities - [Regex Tester](https://devhandy.io/tools/regex-tester): Test JavaScript regular expressions with real-time match group highlighting. - [Cron Generator](https://devhandy.io/tools/cron-generator): Build, test, and translate 5-part cron schedule expressions into plain English. - [Unix Timestamp Converter](https://devhandy.io/tools/unix-timestamp-converter): Convert epoch seconds and milliseconds to human-readable dates and back. - [Color Converter](https://devhandy.io/tools/color-converter): Convert colors between HEX, RGB, HSL, and HSV with interactive picker. - [Text Case Converter](https://devhandy.io/tools/text-case-converter): Convert strings to camelCase, snake_case, PascalCase, kebab-case, and UPPERCASE. - [Text Diff Checker](https://devhandy.io/tools/text-diff-checker): Visual side-by-side comparison of text, code, or configuration files. - [Word Counter](https://devhandy.io/tools/word-counter): Analyze word counts, character counts, reading times, and paragraph densities. - [Character Counter](https://devhandy.io/tools/character-counter): Precise character counter with whitespace and line break controls. - [Lorem Ipsum Generator](https://devhandy.io/tools/lorem-ipsum-generator): Generate classic placeholder dummy text by words, sentences, or paragraphs. ## Design & UI Engineering - [CSS Gradient Generator](https://devhandy.io/tools/css-gradient-generator): Linear, radial, and conic CSS gradient generator with angle and stop controllers. - [CSS Box Shadow Generator](https://devhandy.io/tools/css-box-shadow-generator): Multi-layer elevation and shadow generator with live preview. - [CSS Border Radius Generator](https://devhandy.io/tools/css-border-radius-generator): 8-point organic blob and corner border-radius shaper. - [CSS Button Generator](https://devhandy.io/tools/css-button-generator): Modern button designer with hover lifts, gradients, and cross-browser CSS. - [Glassmorphism Generator](https://devhandy.io/tools/glassmorphism-generator): Frosted glass UI generator with backdrop-filter blur and reflections. - [CSS Clip-Path Generator](https://devhandy.io/tools/css-clip-path-generator): Polygon, star, chevron, and custom geometric clip-path generator. - [CSS Text Shadow Generator](https://devhandy.io/tools/css-text-shadow-generator): Multi-layered neon, 3D, and letterpress text shadow designer. - [CSS Neumorphism Generator](https://devhandy.io/tools/css-neumorphism-generator): Soft UI extruded and debossed shadow generator. - [CSS Pattern Generator](https://devhandy.io/tools/css-pattern-generator): Pure CSS background patterns including polka dots, grids, and stripes. - [CSS Triangle Generator](https://devhandy.io/tools/css-triangle-generator): Pure CSS border and clip-path triangle arrow generator for tooltips. - [Flexbox Playground](https://devhandy.io/tools/flexbox-playground): Interactive visual CSS flexbox container and alignment tester. - [CSS Grid Generator](https://devhandy.io/tools/css-grid-generator): Visual grid track, gap, and area layout designer. - [Responsive CSS Clamp Calculator](https://devhandy.io/tools/css-clamp-calculator): Mathematical clamp() formula calculator for fluid responsive typography. - [CSS Typography Scale Generator](https://devhandy.io/tools/css-typography-scale-generator): Modular typographic scale calculator with musical intervals. - [CSS Units Converter](https://devhandy.io/tools/css-units-converter): Multi-way unit converter between PX, REM, EM, VW, VH, and %. - [CSS Aspect Ratio Calculator](https://devhandy.io/tools/css-aspect-ratio-calculator): Aspect ratio dimensions and responsive padding-top formula calculator. - [CSS Responsive Breakpoint Generator](https://devhandy.io/tools/css-responsive-breakpoint-generator): Media query generator for responsive breakpoints. - [CSS Animation Generator](https://devhandy.io/tools/css-animation-generator): Keyframe animation generator with bounce, pulse, flip, and wobble. - [CSS Transform Generator](https://devhandy.io/tools/css-transform-generator): 2D and 3D CSS transform studio with perspective and rotation. - [CSS Filter Generator](https://devhandy.io/tools/css-filter-generator): Image filter adjustment studio for blur, contrast, brightness, and presets. - [CSS Easing Generator](https://devhandy.io/tools/css-easing-generator): Cubic-bezier curve generator with visual animation race tracks. - [CSS Loader Generator](https://devhandy.io/tools/css-loader-generator): Pure CSS spinners, pulsing dots, and wave bars. - [Color Palette Generator](https://devhandy.io/tools/color-palette-generator): Harmonious color scheme generator with lockable swatches and export. - [Color Contrast Checker](https://devhandy.io/tools/color-contrast-checker): WCAG 2.1 AA and AAA accessibility contrast ratio checker. - [CSS Specificity Calculator](https://devhandy.io/tools/css-specificity-calculator): Specificity calculator and selector comparison tool. ## Optional & Machine Endpoints - [llms-full.txt](https://devhandy.io/llms-full.txt): Comprehensive markdown reference for LLMs with full tool descriptions and parameters. - [sitemap.xml](https://devhandy.io/sitemap.xml): XML sitemap for search engine web crawlers. - [robots.txt](https://devhandy.io/robots.txt): Robot exclusion standard file specifying access and sitemaps.