Guides
Longer, plain-language explanations of the concepts behind our tools — how the calculations work, why the numbers behave the way they do, and what to watch out for.
How EMI Is Calculated: The Complete Guide
The formula behind every loan calculator, explained step by step — including why your first EMI is mostly interest and your last is mostly principal.
BMI Explained: What the Number Does and Doesn't Tell You
BMI takes ten seconds to calculate and one paragraph to misunderstand. Here's what the number is actually measuring.
PDF Compression Explained: How It Works and When to Use It
Not every PDF compresses the same way. Here's what's really being reduced when a 40MB file becomes a 4MB file.
JSON Formatting, Validation and Minification: A Practical Guide
Three different JSON tools, three different jobs. Here's when each one actually matters.
QR Codes Explained: Types, Uses and How Scanning Works
A QR code isn't just a picture — it's a data structure with its own error-correction math built in.
Image Formats Compared: JPG vs PNG vs WebP
Three formats, three different trade-offs between quality, transparency and file size. Here's how to choose without guessing.