Guides & updates.

A vintage filter recolours the photo you already have. An AI recreation replaces the clothes, the room and the camera. Fifteen ready-to-copy prompts, and the details that decide whether the result reads as 1985 or as a modern photo with grain on top.

A bcrypt hash tells you, in the string itself, how expensive it is to attack. Password strength is arithmetic, not an adjective — and a five-word passphrase is 54 bits, not the same as a generated password. Three tools that print the number instead of a feeling.

Twenty-five platform sizes span everything from 9:16 to 4:1, so a crop always discards something — and a centre crop discards the wrong thing about half the time. Why the focal point matters more than the resizing, and when blurred bars beat a sliver.

The HTML parser is required to recover from every error, so nothing ever fails and nobody finds out. What a browser silently rewrites and invents, the forty rules worth checking, and why errors, warnings and notes are genuinely different things.

Why a split PDF should still have selectable text in it, what changes when a page is copied instead of repainted, why picking pages by looking at them beats picking by number, and what rotating a page actually writes into the file.

A PDF holds glyphs at coordinates and not one paragraph mark, which is why a naive conversion welds a hard return to the end of every line. What it takes to rebuild lines, paragraphs and headings — and the four things that cannot come across at all.

What is actually inside a favicon.ico, why a 256-pixel icon has to record its width as zero, why a browser asks for the file whether you mention it or not, and the six sizes that earn their place — with the manifest and the head tags.

Why a thumbnail URL needs no API key, what "unlisted" actually protects, why three of the five sizes are 4:3 with a quarter of their height in black, and what the three numbered frames are for.

Why a PDF contains no pixels at all, where 595.28 comes from, why A3 is exactly two A4s and US Letter is not, when to fit a picture inside the page and when to fill it — and the tool that puts up to forty images into one file.