Guides
Plain-English explainers on the concepts behind the tools — from how a JWT works to what your photos reveal about you. Each guide is practical, jargon-light, and links to a tool you can try right away.
Security
What Is a JWT and How Does It Work?
A plain-English explanation of JSON Web Tokens — their three parts, how signing works, and what they should and should not be used for.
5 min readWhat EXIF Data Reveals About Your Photos
The hidden metadata cameras embed in photos — including GPS location — and how to remove it before sharing.
4 min readHashing vs Encryption: What Is the Difference?
Two concepts that get conflated constantly. When to hash, when to encrypt, and why passwords are hashed but not encrypted.
5 min readHow to Choose Strong Passwords (and Why Length Wins)
What actually makes a password strong, why length beats complexity, and the two habits that matter more than any single password.
4 min readHTML Entities and Escaping: Preventing XSS
Why some characters must be escaped in HTML, how entities work, and how escaping stops cross-site scripting.
4 min readHMAC and Webhook Signatures Explained
How services prove a webhook really came from them, and how HMAC verifies both integrity and authenticity.
5 min readAES Encryption Explained: Keys, Modes, and IVs
How AES works in practice — key sizes, why GCM is the mode to pick, what an IV is for, and how passwords become keys.
5 min readbcrypt Explained: How to Store Passwords Safely
Why passwords need a slow hash, what the parts of a bcrypt string mean, and how to choose a cost factor.
4 min readHTTP Basic Authentication Explained
How the Authorization: Basic header is built, why it is only Base64 and not encryption, and when Basic auth is still fine to use.
4 min readHow TOTP Two-Factor Codes Work
What is inside the QR code your authenticator app scans, how six-digit codes are computed from the time, and why clocks matter.
4 min readCreating and Signing JWTs Safely
How to choose claims, pick between HS256 and RS256, set expiry times, and avoid the classic JWT signing mistakes.
5 min readWeb & APIs
Base64 Explained: Encoding vs Encryption
What Base64 actually does, why data grows by a third, when to use it, and the critical reason it is not a way to hide anything.
4 min readHTTP Status Codes Every Developer Should Know
The five status-code classes, the codes you will actually see, and the ones people mix up like 401 vs 403 and 301 vs 302.
6 min readUTM Parameters: A Practical Guide to Campaign Tracking
What UTM tags are, what each parameter means, and how to keep your analytics clean with a consistent naming convention.
4 min readYAML vs JSON: When to Use Each
Two ways to write the same data. How they differ, where each shines, and the YAML gotchas that catch people out.
4 min readURL Encoding Explained (Percent-Encoding)
Why URLs need encoding, what %20 means, and the difference between encodeURIComponent and encodeURI.
4 min readMinification vs Compression
Two different ways to make files smaller, why you should use both, and what each one actually does.
4 min readURL Slugs and SEO-Friendly URLs
What makes a good URL slug, why hyphens beat underscores, and how URL structure affects search and sharing.
4 min readCORS Explained
Why the browser blocks your API request, what preflight requests are, and how CORS is actually fixed.
5 min readMeta Tags and Open Graph: Better Search and Share Previews
Which HTML meta tags still matter for SEO, how Open Graph and Twitter cards control link previews, and the image sizes to use.
5 min readFavicons Explained: Which Sizes and Files You Need
The minimal modern favicon set — ICO, SVG, Apple touch icon, and web manifest icons — and the HTML to link them.
4 min readUser-Agent Strings Explained (and Why They Lie)
How to read a User-Agent header, why every browser claims to be Mozilla, and what to use instead of browser sniffing.
4 min readFrom curl to Code: Translating HTTP Requests
How the parts of a curl command map to fetch, Python requests, and other HTTP clients — headers, bodies, auth, and redirects.
4 min readCSV vs JSON: Converting Between Tables and Objects
When to use CSV and when to use JSON, how nested data is flattened, and the pitfalls of converting between them.
4 min readXML Explained: Elements, Attributes, and Namespaces
A practical introduction to XML — its syntax rules, elements versus attributes, namespaces, and where XML is still used today.
4 min readTOML Explained: The Config Format Behind Cargo and pyproject
TOML syntax in a nutshell — tables, arrays of tables, and types — and how it compares with JSON and YAML for configuration.
4 min readJSON Schema Explained: Validating JSON Data
What JSON Schema is, the keywords you use most, and how one schema can validate API payloads and generate forms.
5 min readData URIs: Embedding Images with Base64
How data: URIs work, when inlining an image as Base64 helps performance, and when it makes things worse.
4 min readConverting HTML to Markdown: What Survives and What Does Not
How HTML elements map to Markdown, what gets lost in conversion, and tips for clean results when migrating content.
4 min readMarkdown Tables: Syntax, Alignment, and Limits
How to write GitHub-flavoured Markdown tables, align columns, escape pipes, and what to do when a table outgrows Markdown.
3 min readREADME Badges: What They Are and Which to Add
How shields.io badges work, the badges that are actually useful, and how to keep a README from becoming a wall of icons.
3 min readCommon JSON Syntax Errors and How to Fix Them
The JSON mistakes behind "Unexpected token" errors — trailing commas, single quotes, comments, unquoted keys — and how to find them fast.
4 min readMarkdown Flavours: CommonMark vs GitHub Flavored Markdown
Why Markdown renders differently in different apps, what CommonMark standardised, and what GitHub Flavored Markdown adds.
4 min readDev Basics
Understanding Cron Syntax (With Examples)
How the five cron fields work, what the special characters mean, and a set of ready-to-copy schedules for common jobs.
5 min readchmod Explained: 644 vs 755 and Unix Permissions
How Unix file permissions work, what the numbers mean, and when to use 644, 755, 600, and 700.
5 min readUUID v4 vs v7: Which Should You Use?
What UUIDs are, how unique they really are, and why the newer time-ordered v7 is often better for database keys.
4 min readRegular Expressions: A Beginner's Guide
A gentle introduction to regex — the core building blocks, quantifiers, character classes, and groups — with practical examples.
6 min readBinary, Octal, and Hexadecimal Explained
What a number base is, why computers use binary and hex, and how to read each one.
4 min readCharacter Encoding: ASCII, Unicode, and UTF-8
Why text sometimes turns into garbled symbols, and how ASCII, Unicode, and UTF-8 fit together.
5 min readSQL Joins Explained
INNER, LEFT, RIGHT, FULL and CROSS joins in plain English, with the rule of thumb for choosing between them.
5 min readEnvironment Variables: .env Best Practices
Why configuration belongs in environment variables, how .env files work, and the mistakes that leak secrets.
4 min readUnix Timestamps Explained: Epoch Time, Seconds vs Milliseconds
What a Unix timestamp is, how to tell seconds from milliseconds, how time zones fit in, and the 2038 problem.
4 min readSubnetting and CIDR Notation Explained
What /24 means, how to work out network and broadcast addresses, how many hosts a subnet holds, and the private IP ranges.
5 min read.gitignore Explained: Patterns and Common Mistakes
How .gitignore patterns work, what every project should ignore, and how to stop tracking a file that is already committed.
4 min readHow Diffs Work: Reading Unified Diff Output
What the +, −, and @@ lines in a diff mean, how diff algorithms find changes, and tips for reviewing changes faster.
4 min readComparing Two Texts: Line, Word, and Character Diffs
When to compare by line, word, or character, how to ignore noise like whitespace and case, and practical uses beyond code.
3 min readcamelCase, snake_case, kebab-case: Naming Conventions Explained
The common case styles, which languages and contexts use each, and how to convert between them without breaking acronyms.
4 min readHTML vs JSX: The Differences That Trip You Up
Why JSX uses className and htmlFor, how style objects and self-closing tags work, and what to fix when pasting HTML into React.
4 min readGenerating Realistic Test Data (Without Using Real People)
Why you should not copy production data into development, how to generate realistic fake data, and how to keep it reproducible.
4 min readSQL INSERT Statements: Single Rows, Bulk Inserts, and Upserts
How to write INSERT statements, why multi-row inserts are much faster, how to escape values, and how upserts work.
4 min readDatabase Schema Design: Tables, Keys, and Normalization
A practical introduction to designing relational schemas — primary and foreign keys, one-to-many and many-to-many, and normal forms.
5 min readPractising SQL in the Browser: SQLite vs PostgreSQL
How in-browser databases work, the differences between SQLite and PostgreSQL that matter when learning, and an exercise plan.
4 min readSorting Text: Alphabetical, Natural, and Locale-Aware Order
Why file10 sorts before file2, what natural sort is, how case and accents affect order, and how to remove duplicates.
3 min readDiagrams as Code with Mermaid
Why writing diagrams as text beats drawing them, the main Mermaid diagram types, and where Mermaid renders natively.
4 min readRunning Python and JavaScript in the Browser
How browser-based code runners work with WebAssembly and Web Workers, what they can and cannot do, and why they are safe.
4 min readBlock-Based Coding: Learning to Program Visually
How block coding tools like Blockly and Scratch teach programming concepts, and how to move from blocks to real code.
3 min readWorking with CSV Files: Delimiters, Quotes, and Encodings
The CSV rules that cause broken imports — quoting, delimiters, line breaks, UTF-8 and Excel — and how to handle large files.
4 min readTyping API Responses: From JSON to TypeScript Types
How to turn sample JSON into TypeScript interfaces, handle optional and nullable fields, and validate data at runtime with Zod.
5 min readEscaping Strings for JSON, JavaScript, SQL, Shell, and Regex
Why each language has its own escaping rules, which characters need escaping in JSON, JS, SQL, shell, and regex, and when not to escape by hand.
5 min readDesign
CSS Easing and cubic-bezier Explained
Why linear animation feels wrong, how easing curves work, and how to read and build a cubic-bezier timing function.
4 min readWebP vs JPEG vs PNG: Choosing an Image Format
The strengths of each web image format and how to pick the smallest one that still looks right.
4 min readHEX, RGB, and HSL: Color Formats in CSS
Three ways to write the same color, what each is good at, and why HSL is the easiest to adjust.
4 min readColor Contrast and WCAG: Readable Text for Everyone
Why contrast matters, what the WCAG AA and AAA thresholds are, and how to check your colors.
4 min readFlexbox vs CSS Grid: Which Should You Use?
The practical difference between Flexbox and Grid, when each one is the right tool, and how they work together.
5 min readCSS Shapes with clip-path
How clip-path cuts elements into custom shapes, the four shape functions, and the gotchas around shadows and clicks.
4 min readCSS box-shadow Explained: Realistic, Layered Shadows
What each box-shadow value does, why layered shadows look more natural, inset shadows, and keeping shadows fast.
4 min readCSS text-shadow: Readable Text and Stylish Effects
The text-shadow syntax, using shadows to keep text readable over images, and classic glow, outline, and 3D effects.
3 min readCSS Gradients Explained: Linear, Radial, and Conic
How to write linear, radial, and conic gradients, control colour stops, avoid muddy middles, and create hard-edged stripes.
4 min readMesh Gradients: Soft, Organic Backgrounds
What mesh gradients are, how to fake them in CSS with layered radial gradients, and how to keep them subtle and readable.
3 min readCSS Keyframe Animations: A Practical Guide
How @keyframes and the animation property work, timing and fill modes, smooth performance, and respecting reduced motion.
5 min readGlassmorphism and backdrop-filter: Frosted Glass in CSS
How the frosted-glass effect is built with backdrop-filter, how to keep it readable, and its performance and support caveats.
3 min readCSS border-radius: Beyond Simple Rounded Corners
How border-radius shorthand works, elliptical corners with the slash syntax, pills and circles, and organic blob shapes.
3 min readBuilding a Tailwind Colour Scale from One Brand Colour
How Tailwind's 50–950 shade scale works, how to generate a balanced palette from a brand colour, and where each shade is used.
4 min readOptimizing SVG Files: Smaller, Cleaner Vector Graphics
What design tools leave inside exported SVGs, what an optimizer safely removes, and the settings that can break your file.
4 min readSVG Wave Dividers: Curved Section Breaks
How to add wave and curve dividers between page sections with SVG, make them responsive, and match colours exactly.
3 min readExtracting a Colour Palette from an Image
How colour pickers and palette extractors work, why dominant colours are not always the best ones, and using a photo palette in a design.
3 min readLorem Ipsum: Where It Comes From and When to Use It
The origin of Lorem ipsum, why designers use placeholder text, and when real content makes a better design tool.
3 min readHow Fancy Text Generators Work (and Their Accessibility Cost)
Why bold and script text can be pasted anywhere, which Unicode blocks make it possible, and why screen readers struggle with it.
3 min readMaking Readable Code Screenshots
When a code image beats a code block, how to make code screenshots readable on any screen, and how to keep them accessible.
3 min readLogo Design Basics for Developers and Small Teams
The types of logos, how to pick fonts and colours, why simplicity scales, and the file formats a finished logo needs.
5 min readSocial Media Image Sizes and Design Tips
The aspect ratios that matter on social platforms, safe zones for text, and how to resize one design for many formats.
4 min readChoosing the Right Chart: Bar, Line, Pie, and More
How to pick the right chart for your data, when pie charts work and when they do not, and the habits that keep charts honest.
4 min readLanding Page Structure: The Sections That Convert
The section order most effective landing pages share, what goes above the fold, and how to keep a page fast and accessible.
4 min readHow Image to ASCII Art Conversion Works
How brightness maps to characters, why character aspect ratio matters, and how to get crisp ASCII art from a photo.
3 min readResize, Crop, and Rotate: Image Editing Basics for the Web
The difference between resizing and cropping, choosing dimensions for the web, preserving quality, and stripping metadata.
4 min readHow AI Background Removal Works
How segmentation models separate a subject from its background, which photos work best, and how to use transparent PNGs.
3 min readCSS Filter Effects: Blur, Grayscale, Brightness, and More
How the CSS filter functions work, why order matters, drop-shadow vs box-shadow, and filter vs backdrop-filter.
4 min readTools
Docker Compose vs docker run
Why long docker run commands become unmaintainable, what Compose gives you, and how the flags map across.
5 min readBarcodes Explained: EAN, UPC, Code 128, and More
The common barcode formats, what each is used for, how check digits work, and tips for printing barcodes that scan.
4 min readHow QR Codes Work: Error Correction, Size, and Safety
What is inside a QR code, how error correction lets a damaged code still scan, sizing for print, and avoiding QR scams.
4 min readOCR Explained: Getting Accurate Text from Images
How optical character recognition works, why some images fail, and how to prepare scans and photos for the best accuracy.
4 min readWorking with PDFs: Merge, Split, Compress, and Rotate
What a PDF really contains, how merging and splitting work, why some PDFs compress well and others do not, and privacy tips.
4 min readCombining Photos into One PDF
How to turn photos and scans into a clean, single PDF — page order, size, orientation, margins, and keeping the file small.
3 min readText to Speech in the Browser: How It Works
How the Web Speech API turns text into speech, why voices differ between devices, and tips for natural-sounding results.
3 min readCAD File Formats Explained: STEP, IGES, STL, OBJ, and DXF
What each common CAD format stores, the difference between exact solids and meshes, and which format to send for printing or machining.
4 min readWord Count and Reading Time: How They Are Calculated
How word counters define a word, how reading and speaking time are estimated, and typical word counts for common kinds of writing.
3 min read