Quick reference for developers — 1,192 entries across 8 modules: HTTP status codes, HTTP headers, ASCII codes, MIME types, HTML tags, HTML entities, ISO country codes, and cron syntax.
85 status codes from 100 Continue to 511 Network Authentication Required. Each code includes the RFC standard, common causes, and troubleshooting steps.
133 HTTP headers across caching, security, CORS, authentication, content negotiation, and more. Each includes syntax format and real-world example values.
Full ASCII table 0-255 with decimal, hex, binary, octal, HTML entity, and control character keyboard shortcuts. Includes extended ASCII characters.
104 MIME types organized by category: application, text, image, audio, video, font, multipart. Each shows file extension and typical usage.
115 HTML elements documented with usage notes, practical examples, and an interactive live preview playground. Covers all HTML specification elements.
252 HTML character entities including basic entities, Greek alphabet, mathematical symbols, arrows, and special characters with rendered preview.
249 ISO 3166-1 country codes organized by continent. Each entry shows the two-letter code, three-digit numeric code, and geographic region.
Complete cron expression reference with all 5 fields, special characters, named presets, and 14 practical scheduling examples.
Reference Hub — free developer reference. JavaScript enables interactive search, live preview, theme switching, and keyboard shortcuts. Pages: 404 Not Found, 500 Error, Cache-Control, Content-Type, CORS, HSTS, ASCII chart, HTML Tag Reference.