20 Free Online Developer Tools You'll Actually Use
A hand-picked roundup of 20 free, browser-based developer tools — formatters, encoders, generators, diff checkers, and converters that run locally with no sign-up.
Read articlePractical guides, tutorials, and tips for developers and everyday users. Learn how to get the most out of free online tools.
A hand-picked roundup of 20 free, browser-based developer tools — formatters, encoders, generators, diff checkers, and converters that run locally with no sign-up.
Read articleLearn how to convert between Celsius, Fahrenheit, and Kelvin with simple formulas, worked examples, handy reference points, and a quick mental shortcut.
Read articleConfused by miles versus kilometers or pounds versus kilograms? This practical guide covers length, weight, volume, temperature, and speed, with quick conversion tips.
Read articleWeb colors come in HEX, RGB, and HSL. Learn how each format works, how to convert between them by hand, and how to switch instantly with a free online tool.
Read articleComputers only store numbers, so text needs an encoding. Learn how ASCII, Unicode, and UTF-8 turn letters and emoji into bytes, and why garbled text happens.
Read articleUnderstand bits, bytes, and the units that measure them. Learn why KB, MB, and GB sometimes mean 1000 and sometimes 1024, and why your hard drive looks smaller.
Read articleLearn how to calculate a discount and sale price with simple formulas, mental-math shortcuts, percent-off reversals, stacked discounts, and sales tax, plus a free calculator.
Read articleLearn what word count, character count, reading time, and readability scores actually mean, how each is calculated, and how to use them to write clearer, better-targeted content.
Read articleUnderstand how a diff checker compares two blocks of text or code line by line, what the green and red colors mean, and when to reach for a unified or side-by-side view.
Read articleLearn what percentages mean and how to calculate them: finding a percent of a number, reverse percentages, percentage change, mental shortcuts, and common mistakes.
Read articleUnderstand why time zones exist, how UTC differs from GMT, how offsets and daylight saving time work, and how to convert times across zones without mistakes.
Read articleDiscover what Lorem Ipsum is, its surprising origin in a 2,000-year-old Latin text, why designers use placeholder text, when to avoid it, and how to generate it instantly.
Read articleLearn what Morse code is, how dots and dashes work, the alphabet and numbers, why SOS was chosen, where it is still used today, and how to translate it instantly.
Read articleA clear guide to Roman numerals: the seven symbols and their values, the additive and subtractive rules, how to read and write any number, common mistakes, and a free converter.
Read articleUnderstand number bases from the ground up: how decimal, binary, octal, and hexadecimal work, how to convert between them, and where each one shows up in computing.
Read articleA clear guide to camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, and kebab-case: what each style looks like, which languages use it, and when to pick which.
Read articleA beginner-friendly guide to cron expressions: what the five fields mean, the special characters, worked examples, common gotchas, and how to translate any schedule to plain English.
Read articleLearn how CSV and JSON map to each other, how to handle headers, delimiters, quoting, and types, and how to convert between them for free with in-browser tools.
Read articleURL encoding (percent-encoding) lets you safely put spaces, symbols, and Unicode into a web address. Learn how it works, which characters need it, and the encodeURI vs encodeURIComponent gotcha.
Read articleUUIDs are 128-bit identifiers used everywhere from databases to APIs. Learn what they are, how v1, v4, and the newer v7 differ, how unique they really are, and when to use each.
Read articleHashing turns any input into a fixed-length fingerprint — but not all hash functions are equal. Learn what a hash is, why MD5 is broken, why SHA-256 is the modern standard, and how hashing differs from encryption.
Read articleA strong password is your first and cheapest line of defense. Learn the modern rules — length over complexity, passphrases, and why every account needs its own — plus how to generate one in seconds with a free online tool.
Read articleLearn Markdown from scratch: headings, links, images, lists, code blocks, tables, and more. See your Markdown rendered in real time with a free online preview tool.
Read articleA practical guide to color formats in CSS, converting between hex and RGB, understanding HSL, building accessible color palettes, and using free online color tools.
Read articleUnderstand the mortgage payment formula, see worked examples for 15-year and 30-year loans, learn what affects your monthly payment, and calculate yours instantly for free.
Read articleUnderstand what JWT tokens are, how they work, why they are used for authentication, how to decode them, and common security pitfalls every developer should know.
Read articleLearn what CSS minification is, why it matters for page speed and SEO, how it works under the hood, and how to minify your CSS for free with an online tool.
Read articleLearn how to format, validate, and beautify JSON data using a free online tool. Covers common JSON errors, formatting best practices, and real-world use cases for developers.
Read articleA developer-friendly explanation of Base64 encoding: what it is, when to use it, common pitfalls, and a free online tool to encode or decode Base64 strings instantly.
Read articleUnderstand the BMI formula, what your BMI number means, BMI chart categories, limitations of BMI, and calculate yours for free with our online BMI calculator.
Read articleA practical regex cheat sheet covering syntax, quantifiers, groups, lookaheads, and common patterns. Test your regular expressions instantly with the free online regex tester.
Read articleEverything you need to know about Unix timestamps: what they are, how they work, common pitfalls, and how to convert between timestamps and human-readable dates for free.
Read articleToolboxHub offers 42 free browser-based tools for developers and everyday tasks. No sign-up required.
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