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Why iPhone Home Screen Icons Don’t Update: The Hidden “Shadow Cache” in Safari Explained

Why iPhone Home Screen Icons Don’t Update: The Hidden “Shadow Cache” in Safari Explained Last updated: 2026/02/02 “Why isn’t my new icon showing?” “I replaced the image, but the home screen still shows the old one…” If you’ve added a website to your iPhone’s home screen and the icon won’t update, you’ve run into one of Safari’s most confusing behaviors. The real cause is a little-known system inside iOS: Safari’s hidden “Shadow Cache.” In this guide, we’ll break down the entire mechanism— how iOS stores icons, why they don’t refresh, how to force updates, and how tools like OJapp avoid the problem entirely. The Short Answer: iOS Stores Icons in a Separate Hidden Cache When a user adds a website to their home screen (a Web Clip), iOS stores the icon in a dedicated cache separate from normal browser cache. This “shadow cache” has several unique characteristics: Clearing Safari cache does NOT remove it Reloading the webpage does not trigger an update If the icon URL is the same, the old image will always be used The cache can stay for days or longer In other words: once iOS saves an icon, it treats it like an app icon — […]

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HTML, CSS, and JavaScript Explained Like You’re 10 Years Old

HTML, CSS, and JavaScript Explained Like You’re 10 Years Old Last updated: 2026/02/02 When you make a web page, you use three main tools: HTML, CSS, and JavaScript. But many beginners wonder: “What’s the difference between them?” To make it super easy, let’s explain them using a simple example: building a house. HTML is the “frame of the house” HTML creates the structure and content of a web page. In a house, HTML is like: The walls and pillars The rooms The doors and windows Where everything is placed Without HTML, nothing appears on the page — it’s just an empty lot. CSS is the “design and decoration” CSS controls the look and style of everything HTML built. In a house, CSS is like: Painting the walls Choosing the flooring Decorating rooms Making the windows look stylish CSS makes a website pretty, readable, and organized. JavaScript is the “electricity and machines” JavaScript makes things move and react. In a house, JavaScript is like: Lights turning on when you flip a switch Automatic doors opening Clocks that keep ticking Machines that do things when you press a button JavaScript controls all the “when you click this, something happens” actions. Summary: All […]

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How to Publish a Website for Free: A Beginner’s Guide to GitHub Pages

How to Publish a Website for Free: A Beginner’s Guide to GitHub Pages Last updated: 2026/02/02 “ I made a web page… but how do I show it to other people? ” “ I want a link I can open on my phone! ” If that sounds like you, the easiest solution is GitHub Pages. With no server contract, no domain purchase, and no fees, you can publish your website to the world for completely free. What is GitHub Pages? GitHub Pages is a free hosting service for static websites. Cost: Completely free No ads Works by simply uploading an index.html file Generates a public URL you can open on any device It’s the perfect tool for beginners learning web development. Publishing Your Website Takes Only 4 Steps ① Create a GitHub Account It’s free and requires only an email address. Visit https://github.com Create an account (Sign Up) ② Create a Repository (a folder for your site) Log in to GitHub Click the “＋” icon → New repository Name your repository (example: myweb) Select Public Click Create repository This becomes the place where your web files will live. ③ Upload Your index.html Open your new repository Click Add file → […]

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How to View Your Web Page on Your Phone — The Easiest Ways for Beginners

How to View Your Web Page on Your Phone — The Easiest Ways for Beginners Last updated: 2026/02/02 After creating your first web page, the next big question is: “How do I see this on my phone?” The good news is: You don’t need a server, a USB cable, or any technical setup. Here are the three easiest free methods for beginners. Method 1: Use a Free Hosting Service (Recommended) The easiest and most reliable way is to upload your page to a free hosting service. This gives you a URL you can open on any phone. Popular free options: GitHub Pages (free, no ads) Netlify (free) Once uploaded, you get a public link that you can open on your phone or share with others. Simple GitHub Pages Steps Create a GitHub account Create a repository Upload your index.html Enable GitHub Pages in “Settings → Pages” → Instantly accessible from your phone via URL. Method 2: Preview on Your Phone via Local Wi-Fi If your PC and phone are on the same Wi-Fi network, you can view your page locally using a simple “local server.” The most beginner-friendly tool is Live Server in VSCode. How to Use Live Server Open […]

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How to Create a Simple Web Page for Free — A Beginner-Friendly 10-Minute Guide

How to Create a Simple Web Page for Free — A Beginner-Friendly 10-Minute Guide Last updated: 2026/02/02 Most beginners think they need special software or coding knowledge to make a web page. But the truth is you can create a working web page for free using only your computer and a browser. No installations, no tools, no prior experience required. This guide shows the simplest possible method to create your first web page in just 10 minutes. What You Need Only two things: A computer (Windows or Mac) A browser (Chrome, Safari, etc.) That’s all. You don’t need VSCode or any development tools yet. 1. Create a Folder Named “mypage” Your folder will act as the “home” for your first web page. Right-click on your desktop Select “New Folder” → name it mypage 2. Create a File Named “index.html” Open the mypage folder Right-click → “New” → “Text Document” Rename it to index.html In the world of websites, index.html is the default entry page. 3. Open index.html and Paste This Code Right-click the file → “Open with” → Notepad (or any simple editor), and replace everything with the code below: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, […]

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The Truth Behind Paid Apps: Many Are Actually Just Web Pages Inside an App

The Truth Behind Paid Apps: Many Are Actually Just Web Pages Inside an App Last updated: 2026/02/02 Most people assume that mobile apps are built with complex programming languages and advanced frameworks. But the reality is that a large number of paid apps are simply Web pages wrapped inside an app shell. In other words, many apps in the App Store and Google Play are made with ordinary HTML, CSS, and JavaScript—displayed inside a WebView. Why Are So Many Apps “Web on the Inside”? Mobile apps can use a component called a WebView, which is basically a mini-browser inside the app. When developers use WebView, the app behaves like this: The entire UI is just a Web page Buttons and interactions are done with JavaScript Saving data relies on Web mechanisms (localStorage, APIs, etc.) So even though the app icon looks official, the inside is often just a website. Examples of Apps Commonly Built with WebView Surprisingly, these categories are often Web-based: Fortune-telling / horoscope apps Note-taking or journal apps Simple tool apps (counters, calculators, timers) Content viewer apps (blogs, videos, checklists) Reference databases or info apps All of these can run perfectly well with HTML, CSS, and JavaScript—no native […]

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Browser Cache Explained: Why Updates Don’t Show and How Strong/Weak Caches Work

Browser Cache Explained: Why Updates Don’t Show and How Strong/Weak Caches Work Last updated: 2026/02/02 Developers often struggle with a common issue: “I updated the site, but the old version keeps showing.” In nearly all cases, the cause is the browser’s caching system. This article explains strong cache, weak cache, ETag, and Last-Modified in a practical way, and covers why updates don’t appear and how to reliably fix cache-related issues. What Is a Browser Cache? A browser cache stores copies of website data (HTML, CSS, JS, images) to speed up loading and reduce data usage. Major benefits include: Faster page load times Reduced server requests Lower data usage But the same mechanism often causes the infamous problem: changes don’t update because the browser is still using old files. Two Types of Browser Cache: Strong Cache and Weak Cache Browser caching is not one mechanism — it has two levels. ① Strong Cache (No server request until it expires) With strong cache, the browser does not contact the server at all. It uses stored files directly, making this the #1 cause of “updates not showing.” Triggered by headers like: Cache-Control: max-age=◯◯ Expires: ◯◯ If max-age=31536000 (1 year) is set, CSS or […]

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The Limits of Local Storage: Capacity, Deletion Timing, and Safety Explained

The Limits of Local Storage: Capacity, Deletion Timing, and Safety Explained Last updated: 2026/02/01 LocalStorage is commonly used in modern web apps to store user settings and small pieces of data directly on the device. But many developers (and users) are surprised to learn that localStorage has clear limitations, strict capacity limits, and unexpected deletion behaviors—especially on iPhone. This article explains localStorage’s storage limits, why data sometimes disappears, how browsers decide what to delete, and how to use localStorage safely. What Is Local Storage? (Quick Refresher) localStorage is a simple browser-based storage system used to save small amounts of data on the user’s device. It’s commonly used for: Saving UI preferences Keeping temporary flags Preserving PWA setup states Unlike cookies, localStorage does not expire automatically. But that does not mean it stays forever—especially on iOS. How Much Can You Store? Actual Capacity Limits The biggest limitation: localStorage is very small. Most environments allow only around 5MB. Browser / Platform Approx. Capacity iOS Safari ~5MB Android Chrome 5–10MB iOS PWA (standalone) ~5MB Desktop Browsers 10MB around localStorage is meant for very small configuration data—not large JSON files, images, or app datasets. If you exceed the limit, the browser throws a QuotaExceededError […]

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What Is Local Storage? A Simple Guide to Cache, Cookies, and Browser Storage

What Is Local Storage? A Simple Explanation of Cache, Cookies, and Browser Storage Last updated: 2026/01/29 If your phone starts showing messages like “Storage Almost Full” or Safari/Chrome feels slow, one major cause is the amount of locally saved browser data. In this article, we’ll explain—without technical jargon— the difference between cache, cookies, and local storage, and how each one affects your phone. What Is Local Storage? Local storage refers to data that websites and apps save directly on your device. This helps pages load faster and keeps your settings remembered. There are three main types: Cache: Copies of images and previously visited pages (for speed) Cookies: Login information and site preferences Local Storage: Data used by web apps (settings, state, small files) All are useful—but too much stored data can slow down your phone and consume storage. What Happens If You Delete Them? Cache (Safe to Delete Anytime) Stores images, videos, and page snapshots No major downside when removed Pages may load slightly slower the first time Cookies (Delete With Caution) Keep login sessions and site preferences Deleting them logs you out of sites Shopping carts may reset Local Storage (Depends on the App) Used by web apps to […]

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PWA vs Shortcuts vs OJapp — What’s the Difference and Which Should You Use?

PWA vs Shortcuts vs OJapp — What’s the Difference and Which Should You Use? Last updated: 2026/01/29 When adding something to the smartphone Home Screen, there are actually three completely different methods behind it: PWA, Shortcuts, and OJapp. All three place an icon on the Home Screen, but the internal mechanics, usability, flexibility, and shareability are totally different. A Quick Comparison of the Three Methods Method Flexibility Setup Difficulty Shareability Best Use Case PWA Medium–High Moderate Automatic Developers offering an app-like experience Shortcuts Very High Complex Not shareable Users customizing their own Home Screen OJapp High Very easy Shareable via URL Creators who want custom icons for shared links ① PWA (Progressive Web App) PWA allows a website to behave like an app. It is created by the developer and provided to users. manifest.json defines icons, name, and colors Service Worker adds app-like behavior and caching Home Screen launch hides the browser UI User customization is limited, but for website owners, PWAs provide “app-like experience without the App Store.” ✔ Who Should Use a PWA Website owners who want an official app-style experience Blogs, stores, SaaS tools that want branded icons Cases where users should not perform extra configuration ✘ […]