How-To

Tip 20% in New York, nothing in Tokyo, and round up in Paris. Tipping customs differ wildly — here's what's actually expected around the world.

That 25 MB PDF won't attach to your email. Here's why PDFs balloon in size and how to shrink them without turning the text and images to mush.

You sent a photo from your iPhone and your friend on Windows can't open it. That's HEIC. Here's why Apple uses it and how to convert it to JPG.

BMI is a useful screening number — and a widely misunderstood one. Here's what the categories mean, where BMI falls short, and how to read yours sensibly.

Swapping an 'a' for an '@' doesn't make you safe. Here's what actually makes a password hard to crack in 2026 — and why length beats clever symbols.

How many days until the deadline? How long since that date? Counting by hand is deceptively tricky. Here's how date maths works — and the easy way.

AI can remove an image background in seconds. Here is how it works, where it shines, where it struggles, and how to get clean results every time.

Ever exported an image that looked dull or wrong online? Colour profiles are usually why. Here is what they are and which one to use.

A watermark can protect your work or wreck your image. Here is how to add one that deters copying without distracting from the picture.

Aspect ratio decides how your image fits every screen and feed. Here are the ratios that matter and how to crop without distorting or cutting off the subject.