Developer Reference
Quick reference tables for developers, continuously updated.
HTTP Status Codes
Complete 1xx-5xx status code reference with descriptions
ASCII Code Table
Complete 0-127 character code reference
MIME Types Reference
Common Content-Type reference with extensions
HTTP Methods
Safe/idempotent reference for GET/POST/PUT/PATCH/DELETE…
HTML Entities
Named and numeric HTML entities reference
Color Codes
CSS named colors with HEX/RGB and swatches
URL Encoding
Reserved characters and percent-encoding reference
Common Ports
Well-known 0-1023 ports and common services
Regular Expressions
Metacharacters, classes, anchors and quantifiers
Linux Commands
File, process, network and permission commands
Git Commands
clone/commit/branch/merge/rebase reference
HTTP Headers
Request/response header name, kind and meaning
HTML Tags
Structure, text, form, media and semantic tags
File Extensions
Text, code, image, document, media extensions
Character Encodings
UTF-8/GBK/ASCII meaning and usage
Date & Time Formats
Timestamp / ISO 8601 / RFC 3339 examples
SQL Cheat Sheet
SELECT/JOIN/GROUP BY and common statements
Emoji
Emoji categories and meanings
Keyboard Codes
event.key / code / keyCode
Country & Region Codes
ISO 3166 and dialing codes
HTTP Content Types
Content-Type / charset
Language Codes
ISO 639-1 two-letter codes
Currency Codes
ISO 4217 three-letter codes
Frequently Asked Questions
What is the Developer Reference?
A set of zero-maintenance evergreen cheat sheets (HTTP status, ASCII, MIME, HTTP methods, HTML entities, color codes) for high-frequency lookups. All render locally in the browser; no data is uploaded.
Is my data uploaded?
No. Every reference page is static content rendered locally in your browser; nothing is collected or uploaded.
How do I find a code quickly?
Each table has a search box to filter by key, name or description in real time; breadcrumbs link between tables.