Blog

Guides, tutorials and articles about online tools.

Tool guides

How to create a custom QR code for free

Step-by-step guide to create custom QR codes with colors and size. Download as PNG for free.

How to shorten URLs for free: complete guide

Learn to shorten long links for free and share them easily on social media, email and more.

How to count words and characters online

Free tool to count words, characters, sentences and calculate reading time.

How to compress images without losing quality

Compress PNG and JPG images for free without visible quality loss. 100% local processing.

How to generate a secure password in 2026

Guide to create secure random passwords. How many characters to use and best practices.

How to calculate percentages: formulas and examples

Learn to calculate percentages: increases, discounts, percentage differences with formulas and examples.

How to convert units of measurement online

Unit converter: length, weight, temperature, volume and speed. Conversion tables included.

How to convert colors between HEX, RGB and HSL

Complete guide to convert color codes between HEX, RGB and HSL with live preview.

How to validate JSON online: common errors

Validate, format and minify JSON. Find and fix syntax errors quickly.

What is Lorem Ipsum and what is it for?

Origin and history of Lorem Ipsum. How and when to use it in web and editorial design.

How to use an online stopwatch with laps

Online stopwatch with lap marks and countdown timer. No installation needed.

How to calculate your Body Mass Index (BMI)

Calculate your BMI per WHO standards. Category tables, limitations and when to consult a doctor.

What is Base64 and how to use it?

Guide to Base64 encoding: what it's for, how it works and use cases in web development.

How to compare two texts and find differences

Tool to compare texts: find differences, additions and deletions between two documents.

How to find my public IP: location and ISP

Discover your public IP address, approximate location, internet provider and timezone.

How to convert dollars to pesos: exchange rates

Convert between 150+ currencies with updated rates. USD to COP, MXN, ARS and more.

How to change between uppercase and lowercase

Convert text to uppercase, lowercase, title case, sentence case and more instantly.

How to calculate your exact age in years, months and days

Calculate your exact age from your birth date. Includes months, days and next birthday.

What is a UUID and what is it for?

Guide to UUID v4: what it is, how it works and why it matters for unique identifiers.

What is MD5, SHA-256 hash? Complete guide

Understand hash functions: MD5, SHA-1, SHA-256 and SHA-512. Uses, security and differences.

How to calculate discounts and final price with tax

Calculate discounts easily: original price, discount percentage, tax and final price.

What is a URL slug and why does it matter for SEO?

Learn what a slug is, best practices for friendly URLs and their impact on SEO rankings.

Coin flip probability: the math of chance

The math behind flipping a coin. Probability, law of large numbers and gambler's fallacy.

Virtual dice for role-playing and board games

4 to 20-sided dice for D&D, Pathfinder and board games. Roll multiple dice with modifiers.

How to calculate days between two dates

Calculate the exact difference in days, weeks, months and years between any two dates.

What is my zodiac sign? Find out here

Discover your zodiac sign by birth date. Characteristics, element and compatibility.

Chinese zodiac: meaning of the 12 animals

Discover your Chinese zodiac animal by year. The 12 animals, their traits and compatibility.

Daily horoscope: how it works and what it says

Read your free daily horoscope for all 12 signs. Love, health, work and money.

Zodiac sign compatibility

Discover your sign's compatibility with another in love, friendship and work. The best pairs.

How to create CSS gradients: visual guide

Create linear and radial CSS gradients with our visual generator. Copy the code directly.

How to calculate tips around the world

Tipping guide by country. Calculate the tip and split the bill among diners.

Pomodoro Technique: boost your productivity

Complete guide to Pomodoro: 25 minutes work, 5 minute break. With free timer.

How to use regular expressions (regex): guide

Regular expressions guide with examples. Common patterns, syntax and regex tips.

How to create CSS box-shadow with visual generator

Create CSS shadows with visual controls: offset, blur, color and inset.

What is a Unix timestamp and what is it for?

Understand Unix timestamps: what they are, how they work and how to convert them to readable dates.

How to convert between world time zones

Time zone converter: compare time in different cities and countries instantly.

Markdown guide for beginners

Learn Markdown from scratch: headings, lists, links, images, code and tables with examples.

How to minify web code: CSS, JS and HTML

Reduce code size by minifying CSS, JavaScript and HTML. Improve page load speed.

How to create meta tags for SEO and social media

Generate correct HTML meta tags: title, description, Open Graph and Twitter Cards for better SEO.

How to decode JWT tokens: complete guide

Decode JWT tokens and understand their structure: header, payload, signature and expiration.

Social media character limits 2026

Updated limits for Twitter/X, Instagram, LinkedIn, Facebook, TikTok and YouTube.

How to download YouTube thumbnails in HD

Download thumbnails from any YouTube video in maximum resolution. You only need the URL.

How to choose a color palette for your website

Guide to choosing harmonious color palettes. Color theory, 60-30-10 rule and tools.

How to calculate a loan payment

Calculate monthly payments, total interest and loan amortization. With formulas and examples.

Unicode fonts for social media: guide

Generate text with fancy Unicode fonts for Instagram, Twitter/X, WhatsApp and more.

How to encode and decode URLs

Understand percent-encoding: why URLs are encoded, reserved characters and how it works.

How to convert text to binary and back

Convert text to binary, hexadecimal and octal representation. Understand how encoding works.

How to detect the language of a text automatically

Automatic language detection tool. Identify 20+ languages instantly.

Cron expression guide: syntax and examples

Learn cron expression syntax: minutes, hours, days, months. With visual builder.

How to create a favicon for your website

Create custom favicons with text or emoji. Download in multiple sizes for all browsers.

Passphrase vs Password: which is more secure?

Compare passwords vs passphrases. Why passphrases are more secure and easier to remember.

Online random number generator

Generate random numbers with custom range. Useful for raffles, statistics and testing.

How to create tables in HTML and Markdown

Generate tables in HTML, Markdown and CSV easily. Visual table editor without code.

How to improve your typing speed

Measure and improve your typing speed with our typing test. Tips and techniques.

How to check your password strength

Analyze your password security: length, complexity, entropy and estimated crack time.

How the Argentine blue dollar works

Complete guide to the blue dollar: what it is, difference with official, MEP, CCL and how to convert.

How to calculate compound interest

Compound interest formula explained with examples. Calculate your investment growth.

Real-time exchange rates: how they work

Understand how exchange rates work, factors that affect them and how to convert currencies.

How to calculate ROI on investments

Return on investment formula with practical examples. Evaluate your project profitability.

How 401(k) works in the United States

401(k) guide: contributions, employer match, limits, withdrawal and strategies.

Personal loans guide: what you need to know

Everything about personal loans: rates, terms, amortization and how to calculate payments.

How to calculate US taxes 2026

Federal and state tax guide in the United States. Brackets, deductions and FICA.

Spain IRPF guide 2026

Everything about IRPF in Spain: brackets, deductions, personal minimums and how to calculate it.

How to calculate gross-net in Germany

Guide to taxes and contributions in Germany: income tax, social contributions and tax classes.

UK PAYE guide

Everything about PAYE in UK: tax bands, National Insurance, pensions and student loans.

How to calculate aguinaldo in Mexico

Aguinaldo calculation: minimum days, proportional, ISR and when it's paid per labor law.

Brazilian labor termination guide

Everything about labor termination in Brazil: FGTS, notice, 13th salary and rights.

How to calculate liquidation in Colombia

Labor settlement in Colombia: prima, cesantías, interest, vacation and compensation.

France net salary simulator

Calculate your net salary in France: social contributions, CSG/CRDS and income tax withholding.

VAT by country: global comparison

VAT/GST rates in 30+ countries. Compare consumption taxes worldwide.

Complete CSS Flexbox guide

Learn Flexbox from scratch: properties, axes, alignment and practical examples.

How to use CSS Grid for layouts

CSS Grid tutorial: rows, columns, areas, responsive design and real examples.

Glassmorphism: design trend 2026

CSS glassmorphism guide: create glass effects with backdrop-filter and transparency.

How to generate meta tags for SEO

Create optimized meta tags: title, description, Open Graph, Twitter Cards and Schema.org.

Complete robots.txt guide

Everything about robots.txt: Allow/Disallow directives, Sitemap, user-agents and best practices.

How to optimize images for the web

Image optimization guide: compression, formats, lazy loading and best practices.

WebP and AVIF image formats in 2026

Format comparison: WebP vs AVIF vs PNG vs JPEG. Which to use and when.

How to validate JSON for APIs

Validate and format JSON for REST APIs. Common errors, schemas and tools.

Pomodoro technique: complete guide

Learn the Pomodoro technique: intervals, breaks, productivity and recommended tools.

Secure password generator: 2026 guide

How to create secure passwords: length, characters, managers and two-factor authentication.

How to create a professional digital signature

Create your digital signature: draw, type or upload. Download as transparent PNG.

Markdown guide for technical writing

Learn Markdown: syntax, headings, lists, code, tables and extensions like GFM.

How to generate test data for testing

Generate realistic fake data: names, emails, addresses, phones and more for testing.

Regular expressions (Regex) guide

Learn regex from scratch: patterns, quantifiers, groups, lookahead and practical examples.

How to create professional invoices for free

Generate professional PDF invoices: tax info, items, taxes and free download.

Morse code: history and current use

History of Morse code, how it works, character table and its use today.

How to use WhatsApp Business links

Create direct WhatsApp links with predefined messages. Ideal for business and customer service.

Horoscope 2026: predictions for all signs

2026 horoscope predictions for all 12 zodiac signs: love, work, health and money.

Zodiac sign compatibility: complete guide

Discover sign compatibility: ideal couples, friendships and work relationships.

How to calculate BMI correctly

BMI formula, WHO range table, limitations and alternatives to body mass index.

Macronutrient guide for balanced diet

Proteins, carbs and fats: how much you need based on weight, activity and goals.

How much water should you drink per day?

Personalized water intake calculation: weight, physical activity, climate and recommendations.

How to calculate your daily calories (TDEE)

Calculate your TDEE: basal metabolism, activity factor and calories to lose or gain weight.

GPA calculator: student guide

How to calculate your GPA: 4.0 scale, grade conversion, weighted and unweighted GPA.

APA and MLA citation guide

How to cite in APA, MLA and Chicago: books, articles, websites and more with examples.

Web accessibility: WCAG color contrast

WCAG contrast guide: AA/AAA levels, minimum ratios and how to verify accessibility.

How to calculate Monotributo in Argentina: complete guide 2026

Step-by-step guide to calculate your Monotributo payment. Categories A-K, 2025/2026 values, tax, social security and health insurance components.

How to calculate withholding tax in Colombia: complete guide 2026

Step-by-step guide to calculate withholding tax. UVT 2025 value, tables by concept, rates for salaries, services and rent.

How to calculate Stamp Duty in the UK: complete guide 2025/26

SDLT guide: 2025/26 bands, first-time buyer relief, additional property surcharge, and Scotland/Wales differences.

How to calculate Superannuation in Australia: complete guide 2026

Superannuation guide: SG rate 11.5%, employer and voluntary contributions, 15% tax and retirement projection.

How to calculate CTS in Peru: complete guide 2026

CTS guide: formula, May/November deposits, gratification, partial withdrawal and free availability.

How to merge PDF files for free: step by step guide

Guide to combining multiple PDFs into one. Free online tool, no registration needed.

How to split a PDF into multiple files for free

Learn to separate PDF pages. Free online tool to split documents.

How to convert images to PDF for free

Convert JPG, PNG and other images to PDF. Free online tool without uploading files.

How to rotate PDF pages for free

Guide to rotating PDF pages 90, 180 or 270 degrees. Free online tool.

How to use a QR code generator: complete guide

Learn to create custom QR codes for URLs, WiFi, contacts and more. Free tool.

Currency converter guide: real-time exchange rates

How to use the currency converter, understand exchange rates and money exchange tips.

How to resize images without losing quality

Guide to changing image dimensions online for free. Maintain quality when reducing or enlarging.

How to use a JSON validator: detect errors quickly

Guide to validating and formatting JSON online. Find syntax errors instantly.

How to use a color converter: HEX, RGB, HSL

Guide to converting colors between HEX, RGB, HSL and more formats. Free online tool.

How to calculate BMI: formula, chart and meaning

Calculate your Body Mass Index. WHO category chart, limitations and when to see a doctor.