Practical guides
Short, practical guides: how to solve a task yourself and which free tool gets it done faster.
How to convert HEIC to JPG on Windows, iPhone, Mac and online
Why iPhones save HEIC, how to open HEIC on Windows, how to make your iPhone shoot or share JPG, and how to batch-convert HEIC to JPG in the browser.
How to convert PDF to JPG (and JPG to PDF)
Which resolution (DPI) to choose, JPG vs PNG for pages, and how to turn photos and scans into one PDF on a phone or computer without installing software.
How to compress images for a website without losing quality: JPG vs PNG vs WebP
Which format to pick, which quality setting to use, how large images should be and which HTML attributes make pages load faster.
Average typing speed: what is a good WPM and how to improve
How words per minute are calculated, the commonly cited ranges for casual and professional typists, and a practical plan to type faster without losing accuracy.
How to make a favicon: sizes, ICO, apple-touch-icon and web manifest
Which icon files a site actually needs, the sizes, copy-paste HTML, and why a favicon sometimes refuses to update after you replace it.
Barcode types explained: EAN-13 vs UPC vs Code 128
Which barcode to use for retail products, warehouses or documents, how EAN-13 and UPC-A are structured, and a worked check digit calculation.
Time zones: how to schedule a meeting across time zones (and avoid DST pitfalls)
How to find overlapping working hours, why the gap between cities changes in spring and autumn, and how to write an invite nobody misreads.
How to remove EXIF data and location from a photo before posting
What EXIF stores (GPS, phone model, date), why it matters, and how to strip metadata on iPhone, Android, Windows and online.
How loan amortization works: fixed payments vs equal principal
The monthly payment formula, what an amortization schedule shows, a worked $200,000 example and how extra payments change the total interest.
How to scan a QR code from an image or screenshot
Three ways to read a QR code from a picture on a phone or computer without installing apps, and how to spot a malicious code.
Unix timestamp explained: how to convert it to a date
Seconds vs milliseconds, time zones, conversion snippets for JavaScript, Python, Excel and SQL, and the year 2038 problem.