Developer Tools
Development time is often eaten by small things: HTTP status codes, UUIDs, Cron expressions, MIME types, User-Agent parsing, TypeScript types from JSON. Bookmark this page — faster than reading docs.
Developer Tools · 27 tools
UUID Generator
Generate RFC 4122 compliant unique identifiers, including UUID v1, v4 and time-sortable v7, in batches. Fully …
HTTP Status Codes
A complete HTTP status code reference from 1xx to 5xx, searchable and filterable by class. Fully processed in …
Token Counter
Estimate how many tokens your text consumes in major LLM models to keep prompt costs under control. Fully proc…
Cron Expression Generator
Parse and generate cron expressions with visual configuration, including second-level and Quartz style extensi…
MIME Type Lookup
Look up MIME types by file extension across documents, images, audio, video and more. Fully processed in your …
JSON to TypeScript
Generate TypeScript interfaces from JSON samples, handling nested objects, arrays and union types. Fully proce…
ASCII Table
Browse control, printable and extended ASCII characters with search and category filters. Fully processed in y…
Flag Emoji Unicode Reference
A complete reference of 254 flag emoji: every ISO 3166-1 code plus the EU, UN, England, Scotland and Wales. Cl…
Git Cheat Sheet
A curated cheat sheet of the most useful Git commands, organised by category and searchable. Fully processed i…
JSON Schema Generator
Generate a draft-07 JSON Schema from a sample document with nested objects, array item inference and required …
Mermaid Editor
Edit Mermaid diagrams with live preview for flowcharts, sequence, class, state, ER, Gantt, pie, mindmap and jo…
User-Agent Parser
Identify browser, operating system and device information from any User-Agent string. Fully processed in your …
Meta Tag Generator
Generate title, description, keywords, canonical, Open Graph and Twitter Card tags in one go. Title and descri…
UTM Link Builder
Build tracked URLs from the five standard UTM parameters. Existing query strings are preserved rather than clo…
robots.txt Generator
Build a robots.txt from presets or custom rules: choose user-agents, add Allow/Disallow paths, set crawl-delay…
Sitemap Generator
Turn one URL per line into a sitemaps.org-valid XML file, with shared lastmod / changefreq / priority, dedupli…
JSON-LD Generator
Generate JSON-LD for Article, Product, FAQPage, BreadcrumbList, Organization and Event, with required fields f…
gitignore Generator
Pick your stack (Node, Python, Java, Go, Rust, PHP, Ruby, C/C++, Swift, .NET, Flutter) plus editors, OSes and …
JavaScript Playground
Run JavaScript in your browser and see output, errors and timing instantly. Supports console methods, async co…
CSV Test Data Generator
Generate column-based CSV test data with configurable field types, custom separators and optional BOM. Fully g…
Excel Test Data Generator
Generate column-based Excel test data — names, phone numbers, ID numbers, dates, amounts and more — and downlo…
Number Sequence Generator
Generate integer ranges with a step (forwards or backwards), geometric progressions, random integers (deduplic…
JSFuck Encoder
Convert JavaScript into JSFuck — code built from just []()!+. Great for learning language quirks and CTF puzzl…
JS Obfuscator
Obfuscate and compress JavaScript with identifier renaming, string-array encoding, control-flow flattening and…
AAEncode Encoder
Turn JavaScript into AAEncode, a kaomoji-shaped representation of your code. Fun to look at and reversible; ou…
JJEncode Encoder
Encode JavaScript using only $, letters and underscores with JJEncode. A character-set obfuscation scheme like…
SSR Demo
A server-side rendering sample page demonstrating how SSR feeds SEO-friendly markup from a backend handler.
Developer tools provide compact reference, generation and parsing helpers: UUID, token counting, HTTP status codes, MIME, Git, ASCII, Cron, JSON Schema, TypeScript, User-Agent and Mermaid.