OJapp Dev Log

OJapp Splitter Mobile Guide: How to Cleanly Split Photos on Your Phone (Square & 3:4 Only)

OJapp Splitter Mobile Guide: How to Cleanly Split Photos on Your Phone (Square & 3:4 Only) Last updated: 2026/02/05 OJapp Splitter is a lightweight web tool designed to split photos on smartphones using only two essential aspect ratios: Square and 3:4. No app installation is required, and the entire process runs on your device, making it fast, private, and easy to use. This guide explains how to make the most of Splitter on your phone. Why OJapp Splitter Uses Only “Square” and “3:4” Unlike many image-editing apps that offer every possible aspect ratio, OJapp Splitter intentionally limits the options to two: Square: Ideal for icons, SNS thumbnails, profile photos 3:4: Matches almost all smartphone photos and feels natural These two ratios cover more than 80% of real-world mobile use cases, allowing the tool to stay fast, simple, and high quality. 4 Practical Mobile Use Cases for OJapp Splitter 1. Create perfectly aligned Instagram posts Instagram looks simple, but its automatic cropping is strict and often unpredictable. Using the 3:4 ratio keeps compositions stable and prevents accidental cropping. With OJapp Splitter, you can easily create: 3-split vertical posts 6-split tall layouts Your images will stay aligned when previewed on your feed, […]

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SameSite Cookies Explained for Beginners: A Simple Visual Guide

SameSite Cookies Explained for Beginners: A Simple Visual Guide Last updated: 2026/02/07 The SameSite attribute sounds technical, but the idea behind it is actually simple. It controls when a browser is allowed to send your cookies. Modern browsers like Chrome changed their default behavior, which is why cookies are no longer sent automatically across different websites. This guide uses simple visual explanations to help beginners understand the difference between SameSite=Lax, Strict, and None. What Is the SameSite Attribute? SameSite decides under what conditions a cookie will be sent. Before SameSite became strict, cookies were sent everywhere — even when loading images or iframes from another domain. That made cross-site tracking extremely easy. SameSite fixes this by giving browsers clear rules. Visual Guide: The 3 SameSite Modes ::contentReference[oaicite:0]{index=0} SameSite has only three values: Strict — most restrictive Lax — the modern default None — for third-party cookies (requires Secure) ① SameSite=Strict — “Only from your own site.” Strict means the cookie is sent ONLY when navigating inside the same site. For example, a cookie from example.com will: ✔ Send when browsing inside example.com ✘ NOT send when coming from another site’s link ✘ NOT send inside iframes, images, or scripts This […]

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The Real Reason Cookie Consent Banners Exist: GDPR, Tracking, and Modern Web Regulations Explained

The Real Reason Cookie Consent Banners Exist: GDPR, Tracking, and Web Regulations Explained Last updated: 2026/02/07 Cookie consent banners appear on almost every website today. Many beginners hear, “It’s because of GDPR,” but the real reason is deeper: a mix of web technology, privacy regulations, and modern tracking limits. This article explains, in an intermediate and developer-friendly way, why cookie consent is required and what technical changes created this situation. 1. The Critical Difference: First-Party vs Third-Party Cookies The cookie debate is not about cookies themselves, but who creates them and what they’re used for. ① First-Party Cookies Created by the website you are currently viewing Used for login sessions, language settings, shopping carts, etc. GDPR considers them “essential” → consent not required ② Third-Party Cookies Created by external services (ads, analytics, tracking scripts) Can follow users across multiple websites GDPR requires explicit consent Cookie banners exist mainly because of third-party cookies. 2. GDPR Requires “Transparency and Choice” Under GDPR (2018), websites must: Explain why data is collected Allow users to accept or reject tracking cookies Gain explicit consent before using non-essential cookies Because websites serve users globally, GDPR rules effectively became worldwide standards. 3. The ePrivacy Directive (“Cookie Law”) […]

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Why Do Websites Ask “Do You Accept Cookies?” So Often Now? A Beginner-Friendly Guide

Why Do Websites Ask “Do You Accept Cookies?” So Often Now? A Beginner-Friendly Guide Last updated: 2026/02/06 If you browse the web on your phone or computer, you’ve probably noticed that almost every website now asks: “Do you accept cookies?” Years ago, these pop-ups barely existed. So why are they everywhere today? This article explains, in simple terms, what cookies are, why websites ask for permission, and what is safe or risky to allow. What Are Cookies? Cookies are small pieces of data that websites save on your device. Think of them as tiny notes that help the site remember things. Keeping you logged in Saving your language preference Remembering what’s in your shopping cart In other words, cookies are simply a tool that helps websites work smoothly. → By themselves, cookies are not dangerous. So Why Do Websites Ask for Permission Now? The short answer: because privacy laws became much stricter. The biggest change came from Europe’s law called GDPR (General Data Protection Regulation). GDPR requires websites to: Explain what data is collected Ask for permission before tracking users Allow users to reject non-essential cookies Because the internet is global, websites worldwide now follow these rules — which is […]

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When to Clear Your Cache — and When You Definitely Shouldn’t

When to Clear Your Cache — and When You Definitely Shouldn’t Last updated: 2026/02/06 Many users delete their browser cache the moment something “feels wrong.” But cache plays an important role, and deleting it too often can slow things down or even break certain web apps. As someone who builds Web tools and has manually cleared Safari cache hundreds of times while debugging, here’s a practical guide on when you should clear your cache — and when you absolutely shouldn’t. When You SHOULD Clear Cache 1. When a Website Update Isn’t Showing If HTML, CSS, or JS changes aren’t appearing, cache is almost always the reason — especially on iOS Safari, which holds onto files aggressively. Icons not updating CSS changes not appearing JavaScript still running old code For developers: clearing the cache for only the affected domain is the most effective approach. 2. When a WebClip (Home Screen Icon) Refuses to Update iOS uses a separate “shadow cache” for WebClip icons, which is NOT cleared by normal cache deletion. To fix this, go to: Settings → Safari → Advanced → Website Data → Delete the specific domain. This method has a 100% success rate during development. 3. When a […]

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The Safari Cache Delete Technique Every Web Tool Developer Uses — Why “Clear All” Can Make Things Worse

The Safari Cache Delete Technique Every Web Tool Developer Uses — Why “Clear All” Can Make Things Worse Last updated: 2026/02/06 Safari’s cache often gets treated as the “enemy,” especially when web tools stop updating or icons refuse to refresh. But in reality, cache is a performance booster — until you’re developing a tool. After clearing Safari’s cache more than 1,000 times while building WebClip and PWA-related tools, I finally arrived at a method that clears every hidden cache layer without breaking logins or wiping unrelated data. Why the “Clear All” Option Is a Bad Idea The common beginner move is: Settings → Safari → Clear History and Website Data But this causes major problems: You lose every login session Your settings are reset across all sites Shopping carts and preferences disappear Some caches (especially WebClip caches) do NOT get cleared Yes — even after clearing everything, Safari may still keep a shadow cache that prevents updated files or icons from appearing. The Correct Approach: Delete Cache for One Site Only Safari stores cache per domain, which means you can safely delete data for just one website without affecting anything else. For developers or anyone using WebClip, PWA, or custom […]

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JavaScript Isn’t as Free as It Looks: Why Every Action Requires Its Own Script

JavaScript Isn’t as Free as It Looks: Why Every Action Requires Its Own Script Last updated: 2026/02/06 Many beginners start learning web development with one big assumption: “JavaScript can do anything, right?” But once you begin writing it, you quickly realize something surprising: “It looks free, but it’s not actually that free…” JavaScript is powerful—but it is not magic. Even the simplest behavior requires a dedicated piece of code. In other words: One action = one script. “JavaScript can do anything” is half true, half misunderstanding Yes, JavaScript can handle animations, data processing, API calls, DOM updates, and more. But that simply means: “It can do it if you write it.” JavaScript never does the rest for you. It is a language where you must explicitly describe every step. Why one simple action often requires multiple pieces of JS Take something as simple as a calculator button: Get the input value → script #1 Add numbers → script #2 Update the screen → script #3 Handle errors → script #4 Even a tiny “add numbers” tool contains multiple invisible scripts behind the scenes. That’s why JavaScript often feels like: “Freedom… but only if you write everything manually.” JavaScript does nothing […]

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Why OJapp Icons Look So Clean: The Role and Limits of CSS Explained

Why OJapp Icons Look So Clean: The Role and Limits of CSS Explained Last updated: 2026/02/05 Icons created with OJapp look surprisingly clean on both iPhone and Android home screens. Many users ask: “Why does it look so crisp?” This article explains the answer from a CSS perspective. Conclusion First: CSS Handles the Appearance, OJapp Provides the Perfect Material Clean icons are possible thanks to two elements working together: ① High-resolution source images prepared by OJapp ② WebClip’s CSS-like rules that automatically tidy up the icon CSS is a technology for styling. WebClip (the iOS/Android “Add to Home Screen” feature) internally uses rules very similar to CSS. CSS-Based Conditions That Make Icons Look Good To understand why icons look clean, it helps to view the process through the logic of CSS. 1. High-resolution images (1024px+) When CSS uses something like background-size: cover;, low-resolution images get blurry. WebClip behaves similarly—small images lose clarity. 2. Square images (1:1 ratio) Just like object-fit: cover; in CSS, non-square images get cropped. OJapp enforces a perfect square to prevent unpredictable trimming. 3. PNG with transparency works best Home screen icons automatically receive rounded corners—similar to border-radius. Transparent PNGs naturally blend with these shape rules. CSS […]

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What CSS Can and Cannot Do: A Beginner-Friendly Explanation

What CSS Can and Cannot Do: A Beginner-Friendly Explanation Last updated: 2026/02/05 When you start learning web development, one of the first questions you’ll face is: “What exactly can CSS do?” “And what can’t it do?” This article explains the true role of CSS by clearly separating its “can do” and “cannot do” capabilities in a way beginners can easily understand. What CSS Can Do (✓) CSS is all about visual styling. Colors, layout, animation—anything related to appearance is its specialty. 1. Change colors, text, and backgrounds Set text color (color) Add background colors or images Adjust fonts and sizes 2. Control spacing and layout Adjust margins and padding Create layouts using flexbox or grid Align content left, center, or right 3. Create animations and visual effects Fade-in effects (opacity) Rotation and scaling (transform) Complex animations with @keyframes 4. Apply reusable design patterns One of the biggest strengths of CSS is that you can apply the same design to many elements using classes. What CSS Cannot Do (✕) On the other hand, CSS cannot handle logic, data, or interaction. In simple terms: CSS controls appearance, nothing more. 1. Save or store data Store user input (✕) Keep users logged in […]

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The Complete History of iOS WebClip: How Home Screen Icons Evolved and Why the Shadow Cache Exists

::contentReference[oaicite:0]{index=0} The History of iOS WebClip｜How the Home Screen Icon Feature Evolved Over 15+ Years Last updated: 2026/02/02 Today, adding a website to the iPhone home screen feels completely normal. But this feature—called WebClip—was not part of the original iPhone, nor was it designed the way it behaves today. Over time, WebClip evolved dramatically: from simple screenshot-based shortcuts to a complex system involving apple-touch-icon, manifest icons, PWA features, and the infamous Shadow Cache. This article explains: How WebClip was born How it evolved through each major iOS era Why the Shadow Cache exists today Why icons became so difficult to update No English article currently covers this history in depth— so this is the world’s most complete explanation. 2007: iPhone OS 1 — No WebClip Yet The very first iPhone (iPhone OS 1.0) did not have a way to add websites to the home screen. Users could only save bookmarks inside Safari. The concept of a “web icon” sitting beside app icons did not yet exist. 2008: iPhone OS 1.1.3 — WebClip Is Born Apple introduced Add to Home Screen in iPhone OS 1.1.3 (2008). This was the birth of WebClip. Its early characteristics were very simple: The icon was […]