Guides and how-tos
Practical explanations to help you get more from our tools and understand the ideas behind them.
How to Merge and Split PDF Files Without Uploading Them
A practical guide to combining and extracting PDF pages, why it matters where the work happens, and how to avoid common mistakes.
5 min read →PNG vs JPG vs WebP: Which Image Format Should You Use?
How PNG, JPEG and WebP differ, when each is the right choice, and how to pick a format and quality that keep images sharp and small.
4 min read →How Compound Interest Works, With Worked Examples
A plain-language explanation of compound interest, the effect of time and monthly deposits, and how to read a savings projection sensibly.
4 min read →BMI Explained: What It Measures and What It Misses
What body mass index is, how it is calculated, why it is used for screening and where it can mislead. General information, not medical advice.
3 min read →How to Create Strong Passwords (and Actually Remember Them)
What makes a password strong, how random generators and password managers work, and the habits that protect your accounts.
4 min read →How to Reduce Image Size for Faster Websites
A step-by-step approach to shrinking images for web pages: resize, choose a format, set quality, and check the result.
3 min read →Percentages Explained: Five Calculations You Use Every Day
Clear, worked examples of percent of a number, percentage change, discounts, tips and stacked percentages, with common mistakes to avoid.
3 min read →What Is Base64? How It Works and When to Use It
A clear explanation of Base64 encoding, why it exists, how it differs from encryption, and practical uses with images and text.
3 min read →JSON Basics and the Errors Everyone Makes
What JSON is, its syntax rules, and how to find and fix the most common mistakes such as trailing commas and single quotes.
3 min read →How to Write Clean URLs and Slugs
Best practices for web address slugs: length, hyphens, lowercase, changing URLs safely, and how to encode special characters.
3 min read →How QR Codes Work and How to Make One That Scans Every Time
What is inside a QR code, how error correction works, and the practical rules for size, contrast, content and printing.
3 min read →Word Counts, Character Limits and Readability: A Practical Guide
How words and characters are counted, typical limits for essays, SMS, titles and descriptions, reading time, and tips for clearer writing.
2 min read →Clean Up Text Fast: Line Breaks, Duplicates, Case and Comparing Versions
Practical ways to fix messy copied text: joining broken lines, removing duplicate lines, changing case and verifying that two versions match.
2 min read →Unit Conversion Cheat Sheet: Length, Weight, Temperature and Time
The conversions people use most, with exact factors, mental shortcuts and common mistakes, plus how to use the converters.
3 min read →Smart Shopping Math: Discounts, Tips, Sales Tax and Splitting Bills
How to work out real sale prices, stacked discounts, tips and shared bills with clear examples and quick mental shortcuts.
2 min read →How to Scan Documents with Your Phone and Turn Them into a Clean PDF
Step-by-step tips for photographing pages, fixing size and order, and combining them into one small, readable PDF.
2 min read →HEX and RGB Colour Codes Explained, With Contrast Tips for Readable Design
How colour codes work, how to read and choose them, and how to pick text and background colours that people can actually read.
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