Articles

How HDR images differ from SDR, how gain maps (Ultra HDR, Apple HDR) and PQ/HLG work, and how to batch convert HDR photos to AVIF, JPEG XL, or WebP on a Mac.

How to batch convert iPhone HEIC photos to WebP on a Mac. Overcoming the double obstacle: macOS sips can't write WebP, and Google's cwebp can't read HEIC. Dedicated apps, two-step CLI, and Shortcuts.

Learn how to batch convert transparent PNG to WebP on macOS while preserving transparency (alpha channel). Fix black or white background glitches, choose between lossless and lossy, and use the cwebp -exact flag.

Four offline ways to batch convert iPhone HEIC photos to JPG, PNG, or WebP on a Mac: a dedicated app for big batches, plus the Finder Quick Action, Preview, and sips.

Three offline ways to batch convert PNG, JPG, and HEIC to AVIF on a Mac: the AVIF Converter. app, avifenc via Homebrew, and built-in sips. With measured sizes.

Batch convert JPG, PNG, and HEIC to JPEG XL (.jxl) on a Mac, offline: the Image Tool+ app or the cjxl command. macOS's built-in sips can't write JPEG XL.

Three ways to batch convert PNG and JPG to WebP on a Mac: a GUI app, the cwebp command, and online converters. macOS's built-in sips can't write WebP.

WebP vs AVIF compared on file size, HDR, browser support, and encode speed. Verdict: serve both with the picture element, AVIF first, WebP second, JPEG last.

Three ways to get the floor area of a room from a PDF or image floor plan, worked through on a sample plan: clicking corners in a free browser tool, calculating from the dimension lines, and measuring a printout with a scale ruler. Plus m² to ft² conversion and centerline vs internal area.

Four ways to measure lengths on a PDF drawing: a free in-browser tool, the Measuring tool in Adobe Acrobat Pro, free PDF viewers, and a printout with a scale ruler. How to set the scale correctly, handle fax and scan distortion, and get accurate results.

Do HDR photos from an iPhone or Android phone stay HDR on social media? HDR support on Instagram, Threads, X, Facebook, TikTok, Google Photos, Flickr, and more (as of September 2026), and how to make a gain map JPEG that looks right with or without HDR.

Picture-in-Picture (PiP) has been added since iOS 14, which allows videos to always play at the forefront. In this article, I'll show you how to PiP without premium.

In order to use IDFA from iOS 14, you need to get user permission to use IDFA and how to display ads using Google Mobile Ads SDK for iOS 14.

I faced Uncaught (in promise) TypeError: Cannot read property 'tagName' of null error when using Next.js. Scripts in head tags run before body tag appears is the cause.

Supporting a web site built with Next.js for PWA(Progressive Web Apps). Installing PWA web sites, users can see the site without Internet access. next-offline module make it easy to support.

Using GitHub integratioon on Vercel make your service shipping faster. But you can't include [@]mark in your branch name.

To improve page speed faster, building UIkit with essential CSS / JS. This site's uikit.min.css is 50% smaller than the one by default.