ToolBox Pro Blog
Short guides and breakdowns: how to compare texts, what Base64 hides, how to craft a password that survives breaches, and other everyday tasks our tools solve.
How to Compare Two Texts Online and Find Every Difference
A step-by-step guide to comparing two versions of a text or contract and seeing every edit. Word vs line diffing, common mistakes, and why diffs stay invisible.
Base64 in Plain Words: What It Is and What It's For
What a string like SGVsbG8sIHdvcmxkIQ== means, why Base64 is not encryption, and where it appears: email, JWT, data URIs. Encode and decode online in seconds.
Strong Passwords: How to Create One You'll Still Remember Tomorrow
Why swapping a for @ no longer works, whether length or cleverness matters more, how many bits a password needs, and how to remember it without a sticky note.
JSON: How to Validate, Format, and Not Break It
The five most common JSON mistakes that make parsers complain, how pretty-printed output differs from minified, and how to pull a field out of a big object.
Unix Time: What the Number 1788523200 Means and How to Turn It into a Date
Why computers count time as a number since 1970, the seconds-vs-milliseconds trap, what 2038 has to do with it, and how to turn a timestamp into a readable date.
Regex for Beginners: Five Patterns That Solve 90% of Everyday Tasks
What regex is made of — character classes, quantifiers, anchors — plus five ready-made patterns for dates, times, emails, and prices, and how to test safely.
How to Count Words and Characters: When It Matters and What to Count
Characters with or without spaces — what to count when, how many characters make a thousand words, where the 200-words-per-minute norm comes from, and more.
QR Codes for Business: Where They Work and How to Make Them Scannable
Menus, business cards, posters, packaging: where a QR code really saves customers time, why it needs a short link inside, and how to generate one free.
How to Convert CSV to JSON Without Losing Data Along the Way
Does an Excel export turn to mush when converted? Delimiters, quotes, leading zeros in SKUs and other CSV traps — and how to get your data into JSON in a minute.
MD5 and SHA-256 Hashes: What They Are and What They're For
What a hash sum is in plain words, why MD5 must never guard passwords, how SHA-256 differs, and how to verify a downloaded file's integrity by its hash.
HTTP Error Codes: What 404, 500, and the Rest Actually Mean
A plain-English guide to HTTP codes: how 404 differs from 403, who's to blame for a 500, what to do about 502 and 504, and why codes matter for SEO indexing.
Cron Expressions in Plain English: From "*/5 * * * *" to Weekdays at 9:00
What cron's five fields mean, how to run a job every 5 minutes or on weekdays at 9 a.m., and how to test a schedule without waiting for midnight.
Percentages Without Mistakes: Discounts, Markups, and Percent of an Amount
How a 25% discount differs from a 25% markup, why two discounts of 20% and 10% don't add up to minus 30%, and how to calculate percentages of any amount online.
Roman Numerals: How to Read and Write Them Without Mixing Up Centuries
Roman numeral values, the subtraction rule (IV, not IIII), why the Romans had no zero, how to write 2026 in Roman numerals, and where you'll see them today.
UUID: What This Identifier Is and Why It Almost Never Repeats
What those long hyphenated strings of digits and letters are, how many variants UUID v4 has, why it's safe to generate on the spot, and how to create a UUID online.
Text Contrast on Websites: How to Check It and How Much You Need
What the contrast ratio is, why 4.5:1 is the standard for body text, how contrast ties into accessibility and SEO, and how to check your site's colors in a minute.
Morse Code: What "· − − ·" Means and Why It Still Matters Today
How Morse code is built, why the Russian alphabet "sounds" like the Latin one in it, how to signal SOS without a radio, and how to translate text into Morse online.
Lorem Ipsum: Why Designers Fill Mockups With Unintelligible Latin
Where the famous "Lorem ipsum dolor sit amet" came from, why mockups are filled with Latin, and how to generate placeholder text of any length in a second.
JWT tokens: what's hiding behind “eyJhbGciOi…” and how to read it
What a JWT is made of, why tokens start with “eyJ”, how a signature differs from encryption, where to check expiry, and why secrets don't belong in the payload.
How to sort lines: alphabetically, by length, and why “10” comes before “9”
Why “10” sorts before “9”, how alphabetical sorting differs from numeric, how to neutralize letter case and stray spaces, and how to sort a list online in seconds.
How to remove duplicate lines from a list without losing order
Why duplicates creep into email and ID lists, when case and spaces matter, how to remove repeated lines and keep their order, and how to count what was removed.
Unit converter: the key conversion factors and classic mistakes
How many kilometers are in a mile, how a US pint differs from an imperial one, and why the gallon is the trickiest unit of all. A unit-conversion cheat sheet.
BMI: what it is, how it's calculated, and who it doesn't fit
What BMI is and how it's calculated, the WHO categories from underweight to obesity, and the cases where the index misleads: athletes, older adults, children.
How to test your typing speed and actually improve it
How WPM is measured, what counts as office-level versus professional speed, why accuracy beats raw numbers, and which exercises genuinely raise typing speed.
Daily calorie needs: how to calculate yours
How to calculate your daily calorie needs: basal metabolism, total energy expenditure, activity levels, and a −15% deficit for weight loss. Why to recalibrate.
Writing out the amount in words on invoices and contracts
Why invoices and contracts spell the amount out in words, how to write numerals correctly — one ruble, two rubles, five rubles — and where the kopecks go.
Annuity payments: how to calculate a loan yourself
What an annuity payment is, why interest is repaid first, how to calculate the payment with a formula, and which contract terms to check before signing.