Blog
Guides and how-tos for every tool on belun.app.
How to Crop an Image Online Without Uploading It Crop photos to the right shape for any platform — and why doing it in the browser keeps your images private. A practical guide with exact ratios. Reverse Text Online: Letter and Word Reversal Explained How text reversal works, what it's used for, and how to flip any string in seconds with a free browser tool. Flesch Reading Ease and Grade Level Explained — With a Free Checker What the Flesch-Kincaid readability scores mean, why they matter for web writing, and how to use them to cut through dense text. Text to Binary: How ASCII Encoding Turns Characters into Bits A practical guide to how computers store text as binary, how to read binary-encoded strings by hand, and when you'd actually need to do this. Aspect Ratio Calculator: Scale Images and Video Without Distortion How to find equivalent dimensions when resizing images, videos, or UI elements — with examples for 16:9, 4:3, and other common ratios. Binary, Octal, Decimal, and Hex: A Developer's Guide to Number Bases Why computers use binary and hex, how to convert between number bases, and when each system shows up in real-world code. Regular Expressions Explained: Patterns, Flags, and Practical Examples Learn how regular expressions work in JavaScript: flags, character classes, anchors, and common patterns for emails, URLs, and phone numbers. Markdown to HTML: A Practical Guide for Writers and Developers How Markdown-to-HTML conversion works, what syntax is supported, and when a browser-based converter beats a build tool. How to Minify CSS: Tools, Techniques, and What Actually Matters A practical guide to CSS minification — what it removes, how much it saves, and when manual tools make sense over build pipelines. How to Resize Images Online Without Losing Quality A practical guide to image resizing: right dimensions for email, social media, and web — plus how a free browser-based tool works with no upload needed. Unix Timestamps Explained: What They Are and How to Convert Them A practical guide to Unix timestamps — what epoch time means, seconds vs milliseconds, timezones, and how to convert between timestamps and dates. How to Calculate Your Exact Age in Years, Months, and Days A practical guide to age calculation — the exact formula, leap year edge cases, and how to find how many days you've lived. BMI Calculator: How to Calculate Body Mass Index and What It Means A practical guide to BMI — the formula, healthy ranges, limitations, and how to use the calculator for metric and imperial units. How to Create a QR Code for Free (and What to Put In It) A practical guide to QR codes — what to encode, how to create them instantly in the browser, and tips for printing and sharing. How to Convert Units Online: Length, Weight, Temperature & Volume A practical guide to unit conversions — metric vs imperial, common mistakes, and when each unit type matters. How to Compare Two Texts and Spot the Differences Instantly A practical guide to text diffing — use cases, how line-level comparison works, and why browser-based tools keep your data private. Lorem Ipsum: History, Uses, and How to Generate It Free A practical guide to Lorem Ipsum placeholder text — where it comes from, when to use it, and how to generate custom paragraphs instantly for free. UUID v4 Explained: What It Is and When to Use It A practical guide to UUID v4 — how it works, when to use it as a primary key, and how it compares to other unique ID strategies. Hash Functions Explained: MD5, SHA-1, SHA-256, and SHA-512 A practical guide to cryptographic hash functions — what they are, when to use each one, and why MD5 and SHA-1 are no longer safe for security-critical work. Color Codes Explained: HEX, RGB, HSL, and HSV A practical guide to color formats used in web design and development, and how to convert between them instantly. How to Create a Strong Password (and Never Forget It) A practical guide to password strength, entropy, and why a random password generator is safer than anything you can invent yourself. How to Calculate Percentages: Formulas, Examples & Free Tool A practical guide to the four most common percentage problems — with formulas, worked examples, and a free online calculator that updates as you type. WebP vs JPEG vs PNG: When to Use Each Format A practical guide to image formats and how a free online converter can help you pick the right one for photos, graphics, and web use. How to Catch Spelling Mistakes Before They Cost You A practical guide to common spelling errors in English and how a free online spell checker can help you find them instantly. How to Check for Plagiarism Online for Free A practical guide to detecting duplicate content, understanding similarity scores, and avoiding plagiarism in essays and documents. Text Case Styles Explained: camelCase, snake_case, kebab-case & More A practical guide to the most common text case styles — when to use each one and how to convert between them instantly. 5 Grammar Mistakes a Professional Engine Catches That You Might Miss A practical guide to common English grammar errors — and how Harper, an open-source grammar engine, detects them automatically. Character Count Online: Why It Matters and How to Do It Right A practical guide to character counting for social media, SEO, SMS, and coding — with tips on platform limits and how different tools count. DNS Records Explained: A, MX, TXT, CNAME, NS and How to Look Them Up A practical guide to DNS record types, what each one does, and how to query them instantly without installing any tools. JSON Formatting & Validation: A Developer's Practical Guide Why JSON formatting matters, common pitfalls, and how to validate JSON for free in your browser — no tools to install. How to Calculate Triangle Area, Angles & Perimeter: Complete Guide Understand Heron's formula, the Law of Cosines, and triangle classification — with a free online calculator that shows all results instantly. URL Encoding Explained: When, Why, and How to Encode URLs A clear guide to percent-encoding — what it is, when you need it, and how to encode and decode URL strings for free in your browser. How to Count Words Online for Free (and Why It Matters) A practical guide to word counting for students, writers, and developers — with tips on character limits, reading time, and more. Base64 Encoding Explained: What It Is and When to Use It A beginner-friendly guide to Base64 — how it works, real-world use cases, and how to encode or decode strings for free in your browser.