Technical articles
Technical articles on JavaScript, cybersecurity and web tools. No fluff.
HTTP Status Codes Explained: From 200 to 500 (Guide)
What HTTP codes mean: 2xx success, 3xx redirects, 4xx client errors, 5xx server errors. The most important ones (404, 301, 500, 403) explained.
How AI Runs Inside Your Browser (No Servers, No Cloud)
A deep explanation of how artificial intelligence runs 100% in your browser: WebGPU, WebAssembly, ONNX, segmentation models and why this changes the rules.
Core Web Vitals: How to Make Your Website Fast (2026 Guide)
What Core Web Vitals are (LCP, INP, CLS), how to measure them and the real optimizations that improve your site's speed and SEO. A practical guide for developers.
Git Cheatsheet: The Essential Commands (With Examples)
Git cheatsheet with the most-used commands: clone, branches, commits, merge, undo changes, stash and resolving conflicts. A quick reference for developers.
Why Processing Your Data in the Browser Protects Your Privacy
What 'client-side' means, why uploading files to a website is a risk and how local processing gives you back control of your data. Privacy explained.
Regular Expressions: Complete Cheatsheet With Examples
Regex cheatsheet: metacharacters, classes, quantifiers, anchors, groups and lookarounds, plus ready-made patterns (email, phone, URL). Quick reference with examples.
Binary, Decimal and Hexadecimal: Converting Number Bases
Understand number bases: what binary, hexadecimal and octal are, how they convert between each other and why computing uses them. Free converter online.
camelCase, snake_case and More: Converting Text Case
Guide to naming conventions: camelCase, snake_case, PascalCase, kebab-case and when to use each in programming. Convert uppercase and lowercase online.
HEX, RGB and HSL: Understanding and Converting CSS Colors
Guide to CSS color formats: what HEX, RGB and HSL are and when to use each, alpha/transparency and how to convert colors free in the browser.
How to Create a QR Code for Free (URLs, WiFi, vCard and More)
Guide to creating QR codes for free: QR types, error correction levels, design best practices and how to generate them in the browser with no watermark.
How to Compare Two Texts and See the Differences (diff)
What a diff is, how to compare two texts or file versions to see what changed, and what it's used for in programming and document review. Free diff online.
Compress Images Without Losing Quality: Complete 2026 Guide
How to compress JPG, PNG and WebP images, cutting file size without visible quality loss. Format differences, the optimal level and free batch compression.
Convert CSV to JSON (and JSON to CSV): A Complete Developer Guide
How to correctly convert CSV to JSON and JSON to CSV: structure, quotes, commas inside fields, data types and free in-browser conversion.
How to Create a Strong Password (and Why Yours Aren't)
Guide to creating strong passwords: length, entropy, managers, passphrases and common mistakes. Generate strong passwords free and 100% in your browser.
How to Scan Documents to PDF with Your Phone for Free (No Apps)
Learn to scan documents with your phone camera and turn them into PDF for free, with perspective correction, filters and OCR, all in the browser and uploading nothing.
CSS Gradients: Linear, Radial and Conic (Guide With Examples)
Learn to create CSS gradients: linear-gradient, radial-gradient and conic-gradient, color stops, angles and transparency. Generate gradients free online.
Your Photos' EXIF Metadata: What It Reveals and How to Remove It
Photos store EXIF metadata: GPS location, date, camera model and more. Learn what it reveals about you and how to view and remove it to protect your privacy.
How to Optimize SVG and Reduce the Size of Your Icons
Why exported SVGs are too heavy and how to optimize them: metadata, decimals, junk code from editors. Reduce your SVG size for free online.
What Is Base64 and When to Use It (With Examples)
A clear guide to Base64: what it is, how it works, what it's for in images and data URIs, why it isn't encryption and how to encode and decode free in the browser.
What Is a Hash: MD5, SHA-256 and What It's Really For
A clear explanation of hash functions (MD5, SHA-1, SHA-256): what they are, what they're for, why they aren't encryption and how to generate hashes free in the browser.
What Is JSON and How to Format and Validate It Correctly
JSON guide for developers: syntax, types, common errors, how to format (pretty print) and validate JSON, and how to do it free in the browser.
What Is a JWT and How to Decode It (Developer Guide)
Understand JSON Web Tokens: header.payload.signature structure, claims, how to decode a JWT and why they should never store sensitive data.
What Is Markdown: Complete Syntax Guide With Examples
Learn Markdown from scratch: headings, lists, links, images, tables, code and more. The full syntax with examples and how to convert Markdown to HTML.
What Is a Slug and How to Create SEO-Friendly URLs
Learn what a slug is, why it matters for SEO and how to create friendly URLs: lowercase, hyphens, no accents or stop words. Generate slugs free online.
URL Encoding: What It Is, When to Encode a URL and How
Guide to URL encoding (percent-encoding): which characters to escape, the difference between encodeURI and encodeURIComponent and how to encode free online.
How to Remove an Image Background for Free Without Uploading Anything
Complete guide to removing a photo background for free, with AI and 100% in your browser. No watermark, no sign-up and your image never leaves your device.
Cron Syntax Explained: How to Schedule Tasks Step by Step
Learn cron syntax: the 5 fields, asterisks, ranges, lists and steps, with real examples. Build cron expressions free and understand them instantly.
How to Merge and Split PDFs for Free Without Uploading Anything
Guide to merging several PDFs into one or splitting a PDF into parts, free and in the browser. No watermark, no limits and your documents never leave your device.
AES-256-GCM Encryption in the Browser with Web Crypto
Learn to encrypt and decrypt text directly in the browser with AES-256-GCM and PBKDF2 using the native Web Crypto API. No external libraries, 100% private.
Regular Expressions in JavaScript: Complete Guide
Learn regex from scratch with JavaScript. Full syntax, capture groups, flags, lookaheads and the 10 most useful patterns with real-world examples.
What is a Unix Timestamp and the Year 2038 Problem
Understand what Unix time (epoch time) is, how to convert it in JavaScript, and why 32-bit systems will have a problem on January 19, 2038.
Generate UUID in JavaScript: crypto.randomUUID() Guide
Learn to generate v4 UUIDs in JavaScript using the native crypto.randomUUID() API. UUID vs GUID differences, when to use them, and how to generate in bulk.
JavaScript
Native browser functions, Web APIs, cryptography with Web Crypto, UUID generation, regular expressions and modern JavaScript patterns without external dependencies.
Cybersecurity
AES-256-GCM encryption, key derivation with PBKDF2, best practices for safe handling of sensitive data on the frontend and how to protect user privacy in web applications.
Web tools
How to build tools that run 100% in the browser without servers, without sign-ups and without compromising user data. Performance, privacy and user experience as core principles.