QUICKTOOLS GUIDES
Understand the task, then use the tool.
These short guides explain the underlying method, common mistakes, and practical limitations behind selected QuickTools utilities.
How to Calculate Percentages
A practical explanation of percentages, percentage changes, discounts, and common mistakes.
Read guide →How Discount Calculations Work
Understand discount amounts, final prices, and why successive discounts should be calculated step by step.
Read guide →How Image Compression Works
Learn the difference between image dimensions, quality, and file size before compressing a photo.
Read guide →JPG vs PNG vs WebP
A practical comparison of three common image formats and how to choose between them.
Read guide →How to Read and Fix JSON
Understand JSON objects, arrays, strings, commas, and the errors that commonly prevent parsing.
Read guide →Understanding Unix Timestamps
Learn what Unix timestamps represent and how seconds differ from milliseconds.
Read guide →What Base64 Is and Is Not
Understand Base64 encoding, its common uses, and why it should never be treated as encryption.
Read guide →ROI, Margin, and Markup Explained
Keep three commonly confused business calculations separate: return on investment, profit margin, and markup.
Read guide →Why we publish explanations
A utility is more useful when visitors can understand what its result means. The guides are written to give context rather than simply repeat a calculator label or target a search phrase.