Blog

Field notes and practical guides on flag assets, userscripts and browser-only developer tooling.

Two browser windows with a blocked connection between them

6 Aug 20267 min read

Fixing Userscript Cross-Origin Request Errors

Why fetch fails across origins in a userscript, and how GM_xmlhttpRequest, @connect and permission prompts solve it.

userscriptscorsdebugging

Illustration of browser developer tools and converters

6 Aug 20268 min read

Base64 Encode and Decode Without Uploading

How base64 and base64url encoding work, the Unicode problem with btoa and atob, data URIs, and why base64 is not encryption.

base64encodingjavascript

Angle bracket characters being escaped through a funnel

5 Aug 20267 min read

HTML Entity Encoding: When You Actually Need It

Which characters need HTML entity encoding, named versus numeric entities, and why entities alone do not prevent XSS.

htmlencodingsecurity

Frosted translucent glass panels over blurred colour shapes

4 Aug 20267 min read

CSS Glassmorphism: Recipe and Pitfalls

The CSS recipe for glassmorphism panels, backdrop-filter support, performance cost, contrast pitfalls and fallback strategies.

cssuieffects

Shuffled identifier cards next to a time-ordered sequence

4 Aug 20269 min read

UUID v4 vs v7: Which One to Generate

Comparing UUID v4 and v7 for randomness, index locality, sortability and privacy, with a straightforward decision guide.

uuiddatabasesidentifiers

Padlock in a browser window with uploads crossed out

4 Aug 20267 min read

Why Client-Side Developer Tools Are Better for Privacy

Browser-only converters and formatters never transmit your data. What that means in practice, how to verify a tool really runs locally, and where the limits are.

privacydev-toolssecurity

1 Aug 20267 min read

Generate a Favicon From an SVG File

How to build a complete favicon set from one SVG source: ico, PNG sizes, apple-touch-icon, manifest icons and link tag order.

faviconsvgpng

A laptop running a browser with an extension chip beside it

1 Aug 20267 min read

Using Userscripts on Mac and in Safari

How userscript support differs on macOS and Safari, including paid managers, iOS support and debugging tips.

userscriptssafarimacos

A three-part token strip with a key and magnifying glass

1 Aug 20269 min read

Decoding a JWT Safely Without Uploading It

How JWT structure, base64url and claims work, why decoding is not verification, and why you should not paste production tokens into remote tools.

jwtsecurityencoding

Illustration of a vector file converting to a pixel grid

28 Jul 20267 min read

Convert SVG to PNG in the Browser, No Upload

How client-side SVG to PNG conversion works using canvas and Image, covering resolution, transparency, fonts and batch export.

svgpngconversion

Boxes aligned along an axis showing flexbox spacing

28 Jul 20267 min read

Flexbox Cheat Sheet With Practical Examples

A practical Flexbox reference covering container and item properties, alignment, wrapping, the flex-basis trap and common bugs.

cssflexboxreference

Script files being archived into a backup box

28 Jul 20267 min read

How to Back Up Your Tampermonkey Scripts

How to export, sync and restore your Tampermonkey scripts, and what a backup does and does not include.

userscriptsbackup

Overlapping red, green and blue circles with an eyedropper

28 Jul 20268 min read

Hex to RGB: The Maths and a Converter

How hex colour codes convert to RGB and HSL, covering alpha, modern CSS colour functions, oklch and contrast ratio calculation.

colourcssconversion

Browser window with a userscript snippet and an extension icon

28 Jul 20268 min read

Getting Started With Userscripts: A Practical Introduction

What userscripts are, how Tampermonkey and Violentmonkey run them, how to install one safely, how to write your first script, and how to debug it.

userscriptsbrowserautomation

A dropdown country picker with circular SVG country, state and language flags

24 Jul 20267 min read

Circular Flag Icons for a Country Picker UI

Build an accessible country picker with circular flag icons: search, keyboard navigation, ARIA roles and virtualisation for 800+ options.

flagsuiaccessibility

Cutaway of a userscript manager machine with gears and pipes

24 Jul 20267 min read

What Is a Userscript Manager and How It Works

An explanation of how userscript managers inject code, sandbox scripts, and differ from extensions and bookmarklets.

userscriptsbrowsers

A clock face with five asterisk schedule markers

23 Jul 20268 min read

Cron Expressions Explained, With Examples

How cron expressions work: five and six field formats, ranges, steps, day-of-week logic, time zones and platform differences.

cronschedulingreference

Illustration of CSS interface elements and colour swatches

22 Jul 20267 min read

Custom Cursors in CSS: A Complete Guide

How to set custom cursors with the CSS cursor property, hotspot coordinates, size limits, formats and fallbacks.

csscursorsui

A stylesheet feeding circular flag discs into a layout

20 Jul 20267 min read

Country Flag Icons in CSS: A Practical Guide

How to add country flag icons with CSS: background-image, data URIs, mask-image recolouring, sprite sheets and dark mode borders.

flagscsssvg

A script file being added to a browser window with a tick

20 Jul 20267 min read

How to Install a Userscript, Step by Step

A beginner walkthrough for installing your first userscript, from adding a manager to enabling the script on a site.

userscriptsbeginner

Illustration of a printed reference cheat sheet

18 Jul 202610 min read

Regex Cheat Sheet for Everyday Web Work

A practical regex reference covering character classes, quantifiers, groups, lookaround, flags and common recipes for web development.

regexreferencejavascript

Two browser extension icons weighed on a balance scale

16 Jul 20268 min read

Tampermonkey vs Violentmonkey: Which to Use

A factual comparison of Tampermonkey and Violentmonkey covering licensing, browser support, sync, editors and APIs.

userscriptsbrowserscomparison

Grid of circular SVG country, state, language and symbol flags

14 Jul 20268 min read

How to Use Circle Flag SVGs in Any Web Project

A practical guide to embedding circular SVG country, state, language and symbol flags in HTML, React and CSS, including data URIs, sprites, PNG fallbacks and accessibility.

flagssvgcss