Guides & explainers
Longer write-ups on the subjects our tools touch. Each one is written to be useful on its own — the maths behind a loan repayment, what actually makes a password strong, why your images are heavier than they need to be — with links to the relevant tool where it helps.
What Actually Makes a Password Strong
Complexity rules, forced rotation and special characters are mostly theatre. Here is how passwords are actually attacked, and what defends against it.
The Maths Behind Loans and Investments
Every financial calculator runs on three formulas. Understanding them tells you why a 30-year loan costs so much more, and why starting to invest early matters more than the rate.
Why Your Images Are Too Heavy
Images dominate page weight on most sites, and most of that weight is avoidable. Formats, dimensions, quality settings and the two HTML attributes that matter most.
Why Client-Side Tools Are Safer for Sensitive Data
Pasting data into an online tool is a disclosure to whoever runs it. Here is what that actually means, and why browser-side processing changes the risk rather than reducing it.
Regular Expressions: A Practical Introduction
Regex has a reputation for being write-only. Most of that comes from three specific misunderstandings, all of which are fixable in an afternoon.
Character Encoding Explained: Unicode, UTF-8 and Mojibake
Where é comes from, why emoji break string length, and how to trace an encoding problem back to the layer that caused it.