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A complete index of all pages on alexrel.com.

// In short

This page is a complete, searchable index of every public page on alexrel.com. It covers the main pages (Home, About, Cases), four service pages (Web Development, Telegram Bots, GEO & SEO, Consultations), project case studies (TeleGo, LingvoHabit), the Toolbox catalog (52 utilities), the Dev Hub section (tools hub, code snippet libraries by language, and macOS guide), and all published blog articles. Use the sidebar to jump to a section or the search box to find a specific page.

Main Pages 3

Home About Cases with concrete results

Services 4

SaaS & Web Apps Telegram Bots GEO & SEO Consultations

Projects 2

TeleGo LingvoHabit

Dev Hub 9

Dev Hub Sections (4)

Dev Hub Tools Snippets The Mac for developers

macOS Guide (5)

Commands Apps Problems Shortcuts New Mac setup

Toolbox 79

ASCII Art Generator Pixel Painter Vector Painter Font Editor Glyph Matrix Editor Code Snapshot String Transformer HTML to Text & Markdown RTL Text Fixer Epoch Counter Text Diff JSON Toolbox Regex Tester Color Toolbox Cron Expression Parser Password Generator JWT Inspector JWT Attack Playground UUID Generator Hash Generator Encryption Toolbox Universal Decoder QR Code Generator QR Code Scanner Markdown Editor Visual Cryptography Shamir's Secret Sharing OAuth PKCE Generator CSP Header Builder JS Minifier & Obfuscator SQL Formatter CSS & HTML Beautifier YAML, JSON, TOML & .env Converter Passphrase Generator Key Pair Generator API & Web Sandbox HTTP Status Codes Image Optimizer SVG Optimizer Apache VHost Builder Subnet Calculator License & Readme Builder Data Mocker SSL & X.509 Decoder GZip & Brotli Tool Number Base Converter XML Formatter & JSON .htaccess Builder Color Blindness Simulator Chmod Calculator Command Explainer Systemd Service Builder Nginx Config Builder Docker Toolbox DNS & SPF/DMARC Tool Telegram Studio Telegram Webhook Tester Telegram Stars Invoice Schema Studio SEO & GEO Site Audit Fluid & Layout Studio SaaS Metrics Simulator LLM Developer Workbench Webhook Signature Verifier OG Image Generator PDF Toolbox Robots.txt & Sitemap Generator Email Header Analyzer AI Watermark Detector EXIF Inspector LSB Steganography Crypto Codec Hex Viewer & File Inspector Barcode Generator & Scanner Postgres EXPLAIN Visualizer Telegram Bot Audit Device Fingerprint Inspector Image Sheet Slicer CSS Size Calculator

Blog 59

Unauthorized Ads on Your Website: How to Trace Malvertising and Hidden Web Shells (Real Case Breakdown)nginx Builder: How Event-Driven Architecture Answered C10K systemd Builder: How Linux Moved from Init Scripts to Unit Files Command Explainer: How to Read Man Pages and Understand Unix How Computers Represent Numbers: Binary, Hex, and IEEE 754 How LZW Patents Led to gzip, and the Web to Brotli What a Browser Checks in a TLS Certificate Why Hebrew and English Text Jumps Around SVG Optimization, Code Export, and Image Compression Why Developers Still Fight About Code Formatting From Manual Fixtures to a Browser Data Mocker How Diff Chooses Changes and Why Git Has Several Algorithms From CIE XYZ to OKLCH: Making Color More Perceptual JSON Toolbox: Why JSON Fit Web APIs So Well Why Unix Time Starts on January 1, 1970 How Codd's Relational Model Became SQL How curl Grew From httpget Into Network Infrastructure MIT, GPL, and Apache 2.0: How the Licenses Differ in Practice How CIDR Slowed IPv4 Exhaustion and Routing Table Growth How Cron's Five Fields Outlived Generations of Unix HTTP Status Codes: Build Predictable API Contracts JSON, YAML, and TOML: Why the Same Data Behaves Differently The Three Invisible Marks on an AI Image From Hand Ciphers to AES: How the Security Model Changed MD5 Was Broken in 2004. Why Is It Still in Use?RSA or Ed25519: Which SSH Key Should You Choose?How Diceware Turned Random Words into Strong Passphrases How Password Research Changed NIST's Guidance From JSMin to Terser: What Minification Does to JavaScript OG Image Generator: Visual Editor for Open Graph Cards Where Mojibake Comes From in Cyrillic Text How Markdown Became the Web's Plain-Text Language The Secret Hidden Across Two Images How Mathematics Splits a Secret Into Useless Pieces JWT Does Not Encrypt Data: How to Read and Validate a Token How UUIDv7 Made Time Part of UUID Ordering Docker Toolbox: How Docker Made Containers Practical DNS-over-HTTPS (DoH) & Email Security (SPF, DMARC)How I Made Pixel Art Without Opening Photoshop Vector Painter: Trace Raster Icons into Editable SVG The Comprehensive .htaccess & mod_rewrite Guide for Apache Content Security Policy (CSP 3): XSS Defense Guide Securing OAuth 2.0 Applications with PKCE (RFC 7636)Why Denso Wave Made QR Codes Free to Use Telegram Web Apps (TWA): How to Launch a Full SaaS Inside Telegram Generative Engine Optimization (GEO): The New SEO for AI Search Optimizing Your Website for AI Crawlers: Robots.txt & JSON-LD How Much Does SaaS MVP Development Cost in 2026: A Stage-by-Stage Estimate How to Build a B2B SaaS MVP in 30 Days Without Technical Debt The Trap of Cheap Development: When to Rewrite Your SaaS MVP SaaS Monetization: Implementing Stripe, Billing, and Subscriptions Without Pain SaaS Database Architecture: Single-Tenant vs. Multi-Tenant Patterns Codebase Audit Checklist: How to Assess Technical Debt Before Scaling AI-Powered Customer Support: Building a RAG Bot with Live Agent Handover Bot Builder vs Custom Development: How to Choose in 2026 How Much Does Telegram Bot Development Cost in 2026: A Real Price Breakdown What a Telegram Bot Specification Should Include: A Checklist with Examples Why Your CRM Needs a Custom Telegram Bot (HubSpot & AmoCRM Integration)EzSwitch — Quick Keyboard Layout Switcher for macOS

Snippets 134

Bash (1)

yt-dlp — Handy Bash Functions for Video, Audio & Subtitles

CSS (8)

CSS Gradient Text CSS Grid auto-fit — Responsive Grid Without Media Queries Center anything with flexbox Custom CSS Scrollbar Fluid Typography with clamp()Multiline text-overflow with Ellipsis Skeleton Loading Animation (CSS)Truncate single-line text with an ellipsis

Docker (3)

Docker Compose for Node.js + PostgreSQL + Redis Docker multi-stage builds for Node.js Docker security — non-root user and read-only filesystem

Express.js (6)

Centralized error-handling middleware Enable CORS in Express JWT Auth Middleware (Express)JWT access and refresh token rotation in Express Rate limit requests Sanitize an uploaded filename

Git (4)

Git cherry-pick and bisect — target specific commits Git log — filtering and formatting commit history Git squash commits and interactive rebase Git stash — save and restore work in progress

GitHub Actions (4)

GitHub Actions — CI pipeline for PRs GitHub Actions — build and push Docker image to registry GitHub Actions — deploy Node.js app to VPS via SSH GitHub Actions — scheduled tasks with cron

Go (7)

Create a simple HTTP server Generate a UUID HTTP Request with Timeout via Context (Go)HTTP Server with Graceful Shutdown (Go)Make an HTTP GET request Read a file line by line Run tasks concurrently with goroutines

JavaScript (35)

A JSON.parse that never throws Answer Telegram Callback Query Auto-arrange Telegram inline keyboard buttons Capitalize the first letter of a string Check if a hex color is light or dark Check if an event target is an editable field Convert Date to/from "YYYY-MM-DD" without timezone shifts Cosine similarity between two vectors Debounce a function Decode JWT Payload Without Verification Deep Clone an Object Detect the visitor's timezone automatically Display a timezone with its GMT offset Format a date/time in any IANA timezone Format a number compactly (1.2K, 3M)Generate Slug from String Generate a UUID Get IP geolocation info (ipapi.co)Get User ID and Data from Telegram Update Get seconds until the next UTC day/month rollover Lazy-Load Autoplaying Videos with IntersectionObserver Manage a deduplicated, sorted tag list Merge Tailwind classes safely (cn helper)Parse Telegram /start deep-link parameters Parse loose values into a real boolean Pick and omit object keys Pluralize words with Intl.PluralRules Remove duplicates from an array Smooth Scroll to Anchor Telegram User Link and Mention Throttle a function Truncate Text by Word Count Validate Email Address Validate a media URL sleep() / Async Delay

Next.js (5)

Create an API route handler Generate dynamic page metadata Next.js App Router middleware — authentication and redirects Read search params in a Server Component Redirect from a Server Component or Route Handler

Nginx (4)

Nginx WebSocket proxy for real-time apps Nginx load balancing between Node.js instances Nginx reverse proxy with SSL termination Nginx static file server with caching

Node.js (6)

Constant-time string comparison for secrets Create a basic HTTP server Hash and verify a password with bcrypt Read a file asynchronously Read environment variables with defaults Stripe webhook handler with idempotency

PHP (18)

Bcrypt Password Hashing (PHP)Escape text for Telegram MarkdownV2 Format bytes as a human-readable size Generate a colored initials avatar (HTML/CSS)Generate a secure random password Get IP geolocation info (ipapi.co)Get Telegram User ID via PHP Webhook Get a timezone's current GMT offset in PHP Get the real client IP behind a proxy/CDN Make a GET request with cURL Mask a token/API key for safe display Parse a BCP-47 language tag Redis Rate Limiter (PHP)Retry an operation with exponential backoff + jitter Sanitize a string to valid UTF-8 Send Telegram Message via Bot API (PHP)Validate an email address Verify Telegram Webhook Secret

Prisma (4)

Prisma CRUD — create, read, update, delete Prisma migrations — create, apply, and roll back Prisma pagination — cursor and offset Prisma schema — User, Post, and relations

Python (5)

Check if a file or directory exists Flatten a nested list Read a CSV file into a list of dictionaries Retry Decorator with Backoff (Python)asyncio.gather with Concurrency Limit

React.js (6)

React context + useReducer for global state React useMediaQuery — responsive hook useDebounce hook useFetch hook useOnClickOutside hook usePersistedState hook

Tailwind CSS (4)

Tailwind CSS animations — keyframes and transition Tailwind CSS custom theme with CSS variables Tailwind CSS dark mode with class strategy Tailwind CSS responsive card grid

TypeScript (5)

Chunk Array into Groups Group Array by Key Pagination Utilities (Offset / Limit)Zod API validation schemas useFetch with AbortController — TypeScript

Vue (9)

useBreakpoints hook useClipboardCopy hook useDebouncedRef — Delayed Reactive Value useDragAndDrop hook useIntersectionObserver — Vue Composable useMediaQuery — Reactive Media Query usePlatform hook useTheme hook useViewMode hook