Complete Platform Index • 900+ Static Pages
Castov Complete Developer Directory
Browse every interactive developer tool, timezone pair converter, schema generator, regex pattern, network port guide, CIDR block, and Linux permission reference on Castov.
1. Platform Hubs & Flagship Workbenches
All Developer ToolsGlobal Timezone MatrixNetwork Ports & CIDR HubCode & Schema ConvertersRegex Patterns LabDeveloper Error FixesTech Pulse RadarAI Developer HubCursor Rules GeneratorUnix Timestamps HubTime Zones HubCron Expression HubHTTP Status Codes HubEngineering GuidesDeveloper CheatsheetsCastov Terminal CLI
2. Interactive Developer Tools (61)
JSON to TypeScriptDiff CheckerJSON Formatter & ValidatorBase64 Encode / DecodeJWT DecoderUUID GeneratorHash GeneratorService Worker API MockerP2P Ghost TunnelSteganography Env VaultHolographic JSON ExplorerGenetic Regex Auto-HealerChrono-Debug API ReplayAST Conflict TelepathyNexusGridSonic-Gap BridgeQuantum SimulatorGigantic JSON ViewerUnix Timestamp ConverterEpoch ConverterTimestamp to DateDate to TimestampCurrent Unix TimestampMilliseconds to DateISO 8601 to UnixUnix to ISO 8601Timezone ConverterTimestamp DifferenceUTC ConverterDate Difference CalculatorTime Duration CalculatorAdd Time CalculatorSubtract Time CalculatorUnix Timestamp ValidatorEpoch Milliseconds ConverterUnix Timestamp Batch ConverterDate Format ConverterISO 8601 ConverterRFC 3339 ConverterTime Zone Offset CalculatorWorld ClockBusiness Hours ConverterCron Expression GeneratorTimezone Travel SimulatorUniversal Config SyncZero-Knowledge .env VaultUniversal Secret ScannerShadow API Load TesterDocker Architecture VisualizerIn-Browser SQLite FiddleCode to Image GeneratorCSS Glassmorphism GeneratorGitHub README BuilderApp & Screenshot Mockup StudioFavicon & App Icon GeneratorColor Code Converter & Palette StudioLLM Token & Cost VisualizerGit Disaster Recovery & Time-TravelerSVG Keyframe Animator & StudioSynthetic Mock Data StudioCyberChef & Magic Decoder
3. Global Timezone Pair Converters (60)
EST to UTC (New York)UTC to EST (UTC / Greenwich)PST to EST (Los Angeles / San Francisco)EST to PST (New York)PST to UTC (Los Angeles / San Francisco)UTC to PST (UTC / Greenwich)EST to GMT (New York)GMT to EST (London)PST to GMT (Los Angeles / San Francisco)GMT to PST (London)CST to EST (Chicago)EST to CST (New York)CST to UTC (Chicago)UTC to CST (UTC / Greenwich)PST to CST (Los Angeles / San Francisco)CST to PST (Chicago)MST to EST (Denver)EST to MST (New York)PST to MST (Los Angeles / San Francisco)EST to CET (New York)CET to EST (Paris / Berlin)UTC to CET (UTC / Greenwich)CET to UTC (Paris / Berlin)GMT to CET (London)CET to GMT (Paris / Berlin)EST to IST (New York)IST to EST (Mumbai / Bengaluru)PST to IST (Los Angeles / San Francisco)IST to PST (Mumbai / Bengaluru)UTC to IST (UTC / Greenwich)IST to UTC (Mumbai / Bengaluru)GMT to IST (London)IST to GMT (Mumbai / Bengaluru)CET to IST (Paris / Berlin)IST to CET (Mumbai / Bengaluru)EST to JST (New York)JST to EST (Tokyo)PST to JST (Los Angeles / San Francisco)JST to PST (Tokyo)UTC to JST (UTC / Greenwich)JST to UTC (Tokyo)EST to SGT (New York)SGT to EST (Singapore)PST to SGT (Los Angeles / San Francisco)UTC to SGT (UTC / Greenwich)EST to GST (New York)GST to EST (Dubai)GMT to GST (London)GST to GMT (Dubai)CET to GST (Paris / Berlin)EST to AEST (New York)AEST to EST (Sydney)PST to AEST (Los Angeles / San Francisco)AEST to PST (Sydney)UTC to AEST (UTC / Greenwich)GMT to AEST (London)EST to BRT (New York)BRT to EST (São Paulo)UTC to BRT (UTC / Greenwich)CET to EET (Paris / Berlin)
4. Network Ports (42) & IPv4 CIDR Subnets (25)
Port 20 (FTP Data)Port 21 (FTP Control)Port 22 (SSH / SFTP)Port 23 (Telnet)Port 25 (SMTP)Port 53 (DNS)Port 80 (HTTP)Port 110 (POP3)Port 123 (NTP)Port 143 (IMAP)Port 443 (HTTPS)Port 445 (SMB)Port 465 (SMTPS)Port 587 (SMTP Submission)Port 993 (IMAPS)Port 995 (POP3S)Port 1433 (MS SQL Server)Port 1521 (Oracle DB)Port 2375 (Docker Daemon)Port 2376 (Docker TLS)Port 3000 (Next.js / Node / React)Port 3306 (MySQL / MariaDB)Port 3389 (RDP)Port 4000 (GraphQL / Phoenix / Ghost)Port 4200 (Angular CLI)Port 5000 (Flask / .NET / AirPlay)Port 5173 (Vite Dev Server)Port 5432 (PostgreSQL)Port 5672 (RabbitMQ (AMQP))Port 6379 (Redis / Valkey)Port 6443 (Kubernetes API)Port 8000 (Django / FastAPI / Uvicorn)Port 8080 (HTTP Alternate / Tomcat / Proxy)Port 8443 (HTTPS Alternate)Port 8888 (Jupyter Notebook)Port 9000 (PHP-FPM / SonarQube / MinIO)Port 9090 (Prometheus / Cockpit)Port 9200 (Elasticsearch)Port 11211 (Memcached)Port 11434 (Ollama Local LLM)Port 15672 (RabbitMQ Management)Port 27017 (MongoDB)/8 CIDR (255.0.0.0)/9 CIDR (255.128.0.0)/10 CIDR (255.192.0.0)/11 CIDR (255.224.0.0)/12 CIDR (255.240.0.0)/13 CIDR (255.248.0.0)/14 CIDR (255.252.0.0)/15 CIDR (255.254.0.0)/16 CIDR (255.255.0.0)/17 CIDR (255.255.128.0)/18 CIDR (255.255.192.0)/19 CIDR (255.255.224.0)/20 CIDR (255.255.240.0)/21 CIDR (255.255.248.0)/22 CIDR (255.255.252.0)/23 CIDR (255.255.254.0)/24 CIDR (255.255.255.0)/25 CIDR (255.255.255.128)/26 CIDR (255.255.255.192)/27 CIDR (255.255.255.224)/28 CIDR (255.255.255.240)/29 CIDR (255.255.255.248)/30 CIDR (255.255.255.252)/31 CIDR (255.255.255.254)/32 CIDR (255.255.255.255)
5. Code & Schema Converters (21)
JSON to Zod SchemaJSON to Prisma SchemaJSON to Drizzle ORMJSON to SQL (CREATE & INSERT)JSON to Rust Struct (Serde)JSON to Go StructJSON to Python PydanticJSON to GraphQL SchemaJSON to JSDoc TypedefJSON to TypeScriptcURL to JavaScript FetchcURL to Python RequestscURL to AxiosDocker Run to Docker Compose.env to Docker Compose & K8sSQL DDL to Prisma SchemaSQL DDL to TypeScriptCSV to JSON ConverterJSON to CSV ConverterYAML to JSON ConverterJSON to YAML Converter
6. Regex Patterns Library (40)
Email Address ValidationStrong Password PolicyHTTP & HTTPS URL ValidationDomain Name MatcherIPv4 Address ValidatorIPv6 Address ValidatorMAC Address MatcherJSON Web Token (JWT)UUID v4 IdentifierURL Slug MatcherAlphanumeric UsernameInternational Phone (E.164)US Phone Number FormatCredit Card (Visa & Mastercard)IBAN Bank Account MatcherHexadecimal Color CodeRGB & RGBA CSS ColorISO Date (YYYY-MM-DD)24-Hour Time Format (HH:mm:ss)ISO 8601 Combined TimestampHTML Tags Matcher & StripperMarkdown Links ParserYouTube Video ID ExtractorSemantic Version (SemVer 2.0)Docker Image Name & Tag5-Field Cron ExpressionSQL Injection Detection PatternCross-Site Scripting (XSS) Script TagLeading & Trailing WhitespaceDuplicate Consecutive WordsCSV Comma-Separated Line ParserJSON Object Key ExtractorBase64 Encoded StringMD5 Hash ChecksumSHA-256 Hash ChecksumGit Commit SHA-1 & SHA-256.env Configuration Key-ValueLocalhost Web OriginImage File Extension MatcherArabic Unicode Characters
7. Developer Error Fix Encyclopedia (35)
Next.js Hydration FailedCORS 'Access-Control-Allow-Origin' MissingDocker: Bind for 0.0.0.0:Port FailedPostgreSQL: Remaining Connection Slots ReservedSQLite: Database is Locked (SQLITE_BUSY)Node.js: ERR_OSSL_EVP_UNSUPPORTEDTS: Cannot find module or its type declarationsPrisma Error P1001: Can't Reach DatabaseJWT Malformed / TokenExpiredErrorNginx 502 Bad GatewayNginx 413 Request Entity Too LargeGit: Refusing to merge unrelated historiesGit: Detached HEAD StateReact: Too many re-rendersReact: Maximum update depth exceededNode.js: JavaScript heap out of memoryNPM: ERESOLVE unable to resolve dependency treeDocker: no space left on deviceRedis: MISCONF Errors writing to RDBWebpack: Module parse failedFetch: TypeError: Failed to fetchSSL: NET::ERR_CERT_AUTHORITY_INVALIDKubernetes: CrashLoopBackOffKubernetes: ImagePullBackOff / ErrImagePullPostgreSQL: deadlock detectedMySQL: ER_NOT_SUPPORTED_AUTH_MODETypeScript: Object is possibly 'undefined'Next.js: Dynamic server usageCSP: Refused to execute inline scriptVite: Failed to resolve importGraphQL: Syntax Error Expected NameDynamoDB: ProvisionedThroughputExceededExceptionAWS S3: Access Denied (403 Forbidden)Systemd: Start request repeated too quicklySSH: Permission denied (publickey)
8. AI Developer Hub (30) & Live Tech Trend Radars (30)
.cursorrules GeneratorClaude System Prompt BuilderGPT-4o System Prompt GeneratorCopilot Instructions GeneratorWindsurf Rules GeneratorFew-Shot Prompt FormatterChain of Thought Prompt BuilderAI Agent Persona DesignerOllama Modelfile BuilderGGUF VRAM EstimatorvLLM Config GeneratorContext Window Memory CalculatorHuggingFace Modelcard GeneratorOpenWebUI Pipeline ConfiguratorLLM API Cost CalculatorRepo Token EstimatorEmbedding Cost CalculatorFine-Tuning Cost EstimatorRAG Chunk Size CalculatorLLM Latency Benchmark CalculatorJSON Schema Tool Calling GeneratorPydantic Structured Output BuilderVercel AI SDK Code GeneratorLangchain Boilerplate BuilderMCP Config BuilderREST API to AI Tool ConverterAI Guardrails ConfiguratorPrompt Markdown JSON EscaperJSONL Dataset FormatterLLM Eval Rubric GeneratorTrend Radar: #ai-agents (AI Agents & Autonomous Workflows)Trend Radar: #mcp (Model Context Protocol (MCP))Trend Radar: #llm (Large Language Models (LLMs))Trend Radar: #rag (RAG & Vector Search)Trend Radar: #webgpu (WebGPU & Browser AI)Trend Radar: #rust (Rust Systems Programming)Trend Radar: #typescript (TypeScript & Type Systems)Trend Radar: #python (Python & FastAPI Ecosystem)Trend Radar: #golang (Go (Golang) & Cloud Native)Trend Radar: #zig (Zig & Low-Level Systems)Trend Radar: #webassembly (WebAssembly (WASM))Trend Radar: #nextjs (Next.js & React Server Components)Trend Radar: #react (React 19 & UI Engineering)Trend Radar: #svelte (Svelte 5 & Runes)Trend Radar: #astro (Astro & Content-First Web)Trend Radar: #tailwindcss (Tailwind CSS & Design Systems)Trend Radar: #bun (Bun & High-Speed JS Runtimes)Trend Radar: #docker (Docker & Containerization)Trend Radar: #kubernetes (Kubernetes (K8s) & Cloud Native)Trend Radar: #devops (DevOps, CI/CD & Platform Engineering)Trend Radar: #linux (Linux Kernel, eBPF & Shell Tooling)Trend Radar: #self-hosted (Self-Hosted & Homelab Open Source)Trend Radar: #postgresql (PostgreSQL & Modern Databases)Trend Radar: #sqlite (SQLite, Local-First & CRDTs)Trend Radar: #cybersecurity (Cybersecurity, AppSec & Zero-Trust)Trend Radar: #graphql (APIs, GraphQL, gRPC & OpenAPI)Trend Radar: #git (Git Workflows & Version Control)Trend Radar: #neovim (Neovim, VS Code & AI Editors)Trend Radar: #web3 (Cryptography, Zero-Knowledge (ZK) & Web3)Trend Radar: #system-design (System Design & High-Scale Architecture)
9. Engineering Guides, Cron Schedules & HTTP Status Codes
Guide: Running Local LLMs with WebGPUGuide: Understanding MCP ProtocolGuide: Optimizing .cursorrulesGuide: The Zero-Server AI EraGuide: Advanced Prompt PatternsGuide: Understanding Regex ASTGuide: Mastering Docker ComposeGuide: What Is Unix Time?Guide: Seconds vs Milliseconds TimestampsGuide: ISO 8601 Date and Time FormatGuide: Time Zones and DST for DevelopersGuide: The Year 2038 ProblemGuide: UTC vs GMT: What Is the Difference?Guide: Cron Expressions ExplainedGuide: Linux File Permissions & Chmod GuideGuide: JSON Web Tokens (JWT) Security Best PracticesGuide: Unix Timestamps in Python, JavaScript, and GoGuide: Understanding Diff Algorithms and Patch WorkflowsCron: Every minuteCron: Every 5 minutesCron: Every 15 minutesCron: Every hour on the hourCron: Daily at midnightCron: Daily at 09:00Cron: Weekdays at 09:00Cron: Weekdays at 18:00Cron: Sunday 03:00Cron: 1st of the monthCron: 15th of the monthCron: 1 January at midnightHTTP 100 ContinueHTTP 101 Switching ProtocolsHTTP 200 OKHTTP 201 CreatedHTTP 202 AcceptedHTTP 204 No ContentHTTP 206 Partial ContentHTTP 301 Moved PermanentlyHTTP 302 FoundHTTP 304 Not ModifiedHTTP 307 Temporary RedirectHTTP 308 Permanent RedirectHTTP 400 Bad RequestHTTP 401 UnauthorizedHTTP 403 ForbiddenHTTP 404 Not FoundHTTP 405 Method Not AllowedHTTP 408 Request TimeoutHTTP 409 ConflictHTTP 410 GoneHTTP 413 Payload Too LargeHTTP 415 Unsupported Media TypeHTTP 422 Unprocessable ContentHTTP 429 Too Many RequestsHTTP 500 Internal Server ErrorHTTP 502 Bad GatewayHTTP 503 Service UnavailableHTTP 504 Gateway TimeoutHTTP 505 HTTP Version Not Supported
10. Complete Linux Chmod Octal Reference (000 to 777 — All 512 Combinations)
Direct reference links for every three-digit octal file permission mode in Linux and Unix.
000001002003004005006007010011012013014015016017020021022023024025026027030031032033034035036037040041042043044045046047050051052053054055056057060061062063064065066067070071072073074075076077100101102103104105106107110111112113114115116117120121122123124125126127130131132133134135136137140141142143144145146147150151152153154155156157160161162163164165166167170171172173174175176177200201202203204205206207210211212213214215216217220221222223224225226227230231232233234235236237240241242243244245246247250251252253254255256257260261262263264265266267270271272273274275276277300301302303304305306307310311312313314315316317320321322323324325326327330331332333334335336337340341342343344345346347350351352353354355356357360361362363364365366367370371372373374375376377400401402403404405406407410411412413414415416417420421422423424425426427430431432433434435436437440441442443444445446447450451452453454455456457460461462463464465466467470471472473474475476477500501502503504505506507510511512513514515516517520521522523524525526527530531532533534535536537540541542543544545546547550551552553554555556557560561562563564565566567570571572573574575576577600601602603604605606607610611612613614615616617620621622623624625626627630631632633634635636637640641642643644645646647650651652653654655656657660661662663664665666667670671672673674675676677700701702703704705706707710711712713714715716717720721722723724725726727730731732733734735736737740741742743744745746747750751752753754755756757760761762763764765766767770771772773774775776777