Guides & how-tos
Short, practical guides that explain how to use FreetoolsY tools and the concepts behind them.
What is a QR code and how do you make one?
QR codes explained: how they work, where they are used, and how to generate a custom QR code in seconds with FreetoolsY.
All guidesHow to create strong passwords and test their strength
Password security made simple: what makes a password strong, how a generator creates secure passwords, and how to check strength in real time.
All guidesWhat is Base64 encoding and when should you use it?
Learn how Base64 works, why email, JSON and HTML use it, and how to encode or decode text and images instantly in your browser.
All guidesCurrency converter: how to calculate exchange rates
Understand exchange rates, how currencies are quoted, and how to convert money quickly with or without live rates.
All guidesWhat is a JSON formatter and how do you use it?
Learn what JSON formatting is, why clean indentation matters, and how to format, validate and pretty-print JSON instantly in your browser.
All guidesMeta tags explained: writing title & description for SEO
Understand the essential meta tags — title tag and meta description — and how to write optimized, click-worthy metadata for every page.
All guidesHow to Convert PNG to JPG (and When to Keep PNG)
Learn the difference between PNG and JPG, how to convert PNG to JPG in your browser, and which format to keep for logos, screenshots and photos.
All guidesWebP vs PNG vs JPG: which image format should you use?
Compare WebP, PNG and JPG by size, quality, transparency and browser support, and get a clear rule for picking the right format for any image.
All guidesWhat is SHA-256 and why does it matter?
Understand what a SHA-256 hash does, where developers use it for file integrity and security, and how to verify a download yourself.
All guidesWhat is BMI and how do you calculate it?
Body Mass Index explained: the formula, the categories, its limits, and how to check your BMI in one click with FreetoolsY.
All guidesHow to convert hex, RGB and HSL colors
Convert between hex, RGB and HSL, pick colors from images, and generate harmonious palettes with FreetoolsY.
All guidesUnix timestamp converter: how Unix time works
Understand Unix time, why developers store timestamps instead of dates, and how to convert seconds or milliseconds to a human-readable date.
All guidesJSON-LD explained: structured data that helps you rank
Learn what JSON-LD is, why Google uses it to build rich results, and how to generate clean, valid structured data in seconds.
All guidesHow to calculate the electricity cost of an appliance
Turn wattage and usage hours into monthly and yearly cost. A simple formula, walked through with an energy cost calculator.
All guidesCompound interest calculator: how compounding works
Understand compound interest, the formula behind it, and how a small monthly amount grows into a large sum over time.
All guidesMarkdown to HTML: a practical guide for writers
Turn Markdown into clean HTML for blogs, emails and docs — learn the basics of conversion and how to convert Markdown to HTML instantly.
All guidesWhat is a MIME type and why does it matter?
Learn how MIME types label files for browsers and servers, where to find them and how to look one up from any extension.
All guidesWhat is robots.txt and how do you write one?
Understand the robots.txt protocol, which folders and files to block, and how to generate a correct file with a robots.txt generator.
All guidesHow to check color contrast for WCAG accessibility
Test foreground/background contrast for WCAG AA and AAA, and make sure every visitor can read your interface.
All guidesSQL formatter: write readable queries in seconds
Learn why formatted SQL is easier to debug and review, how keyword casing and indentation help, and how to format queries instantly.
All guidesJSON vs CSV: which format should you use?
Compare JSON and CSV for data exchange, import or export, and convert between both formats without losing structure.
All guidesHreflang guide: the right page for every language
Learn what hreflang tags do, why multilingual sites need them, and how to generate correct hreflang links with a hreflang generator.
All guidesURL structure explained: every part of a web address
Break a URL into protocol, host, path, query and hash. Learn what each piece does and how the browser reads them.
All guidesWhat is reading time and how is it estimated?
Why 'X min read' labels exist, how word count becomes a time estimate, and how to compute it for any text.
All guidesHow to remove emojis from any text
Clean emojis and decorative symbols out of text for publishing, data export or plain copy. Instant, free and entirely in your browser.
All guidesTOTP and 2FA: how time-based codes work
Understand time-based one-time passwords (TOTP), why two-factor authentication protects accounts, and how the code is generated.
All guidesWheel of names: run a fair random picker
Use a wheel of names, a random number generator and a shuffle tool to run fair giveaways, draw winners and assign teams.
All guidesHow to compress images without losing quality
Learn how image compression works, when to use JPG, PNG or WebP, and how to shrink image file sizes in your browser for free.
All guidesHow to decode a JWT (JSON Web Token)
Understand what a JWT is, what its three parts mean, and how to decode the header and payload safely in your browser without sending the token anywhere.
All guidesWhat is a UUID and how do you generate one?
Learn what a UUID is, what the versions mean, and how to generate random UUID v4 identifiers instantly in your browser for free.
All guidesHow to calculate a tip and split the bill
Learn how to work out a tip percentage, split a bill between any number of people, and use a tip calculator for fast, accurate results.
All guidesWhat is WPM? Understanding your typing speed
Learn what words per minute (WPM) means, what counts as a good typing speed, and how to measure and improve your own WPM for free.
All guidesHow to remove an image background for free
Learn how background removal works, when to use it, and how to erase an image background online in your browser without uploading your photo anywhere.
All guidesHow to check the strength of a password
Understand what makes a password strong, why length beats complexity, and how to test your password strength for free without sending it over the internet.
All guidesURL encoding explained: what %20 and %2F mean
Learn what percent-encoding (URL encoding) is, which characters must be escaped, and how to encode and decode URLs online for free.
All guidesHow to calculate a loan EMI (monthly payment)
Learn the EMI formula, how interest rate and loan term affect your monthly payment, and how to estimate a loan payment quickly with a free calculator.
All guidesHow to create a favicon for your website
Learn what a favicon is, which sizes and formats you need, and how to generate a favicon from text or an image and add it to your site for free.
All guidesHow to make an acronym from a name or phrase
Learn how to build acronyms from names, words and phrases: the rules, three common methods and a step-by-step approach you can apply in seconds.
All guidesHow to write cron expressions: fields, examples and testing
Learn what a cron expression is, what each of the five fields means, common schedule patterns, and how to test a cron job before you trust it.
All guides