Free Online Tools
developers & power users

Encode plain text to Base64 or decode Base64 back to text.

Convert plain text to binary and back

Convert colors between HEX, RGB, HSL, and HSV formats instantly in your browser.

Convert between CSS units: px, rem, em, vw, vh, pt, cm, mm, and in

Convert CSV data to JSON or JSON arrays back to CSV format instantly.

Format a number as a currency string for any locale and currency

Convert between decimal and binary data storage units.

Paste a list of HEX colour codes and convert them all to RGB at once

Convert Markdown to HTML instantly in your browser. Preview the rendered output and copy the raw HTML source.

Convert integers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) instantly.

Convert between px, rem, and em CSS units instantly with a configurable base font size.

Convert Arabic numbers to Roman numerals and back instantly. Supports 1–3999.

Convert speed between mph, km/h, m/s, knots, and Mach instantly.

Convert between Celsius, Fahrenheit, Kelvin, and Rankine

Convert date and time between any two time zones instantly. Supports 34 global time zones.

Convert length, weight, temperature, area, and volume units instantly.

Convert between Unix epoch timestamps and human-readable dates.

Percent-encode a string for safe use in URLs, or decode an encoded URL string back to plain text.

Generate and preview CSS box shadows visually. Stack multiple shadows and copy the ready-to-use CSS.

Check WCAG AA and AAA contrast ratios between foreground and background colours

Parse and explain cron expressions in plain English. See the next 5 run times and explore common cron patterns.

Create beautiful linear and radial CSS gradients with a live preview and instant CSS output.

Minify CSS and compare input and output sizes in your browser.

Compare two texts side by side with line-by-line diff highlighting. See added, removed, and changed lines instantly.

Generate MD5, SHA-1, and SHA-256 cryptographic hashes from any text string instantly in your browser.

Encode special characters to HTML entities or decode HTML entities back to plain text — instantly in your browser.

Prettify or minify raw HTML markup with configurable indentation

Browse, search, and look up all HTTP status codes with descriptions and usage guidance.

Upload an image and click any pixel to sample its HEX, RGB, and HSL color values

Minify JavaScript and compare input and output sizes in your browser.

Convert JSON to YAML and YAML to JSON instantly in your browser — no libraries, no upload.

Format, validate, and minify JSON data instantly in your browser.

Validate a JSON document against a JSON Schema and see errors highlighted inline

Decode and inspect JSON Web Token (JWT) header, payload, and claims.

Generate lorem ipsum placeholder text by paragraphs, sentences, or words.

Preview how your page appears in Google search results and social media cards

Look up the MIME type for any file extension, or find extensions for a MIME type

Test regular expressions against a string with live match highlighting, match list, and flag toggles.

Format and beautify SQL queries with configurable indentation

Break a URL into its component parts: protocol, host, path, query parameters, and hash

Format YAML, validate syntax, and create compact output in your browser.

Convert text into large ASCII art letters using block, shadow, or outline styles. Copy and use anywhere.

Generate Code 39 and EAN-13 barcodes from text or numbers.

Generate harmonious color palettes from any base color. Choose complementary, analogous, triadic, and more. Copy as CSS variables instantly.

Create a custom favicon from text or emoji. Choose shape, colors, and download in all standard sizes.

Generate a multi-step colour gradient between two hex values.

Generate strong, random passwords with custom length and character sets.

Generate custom placeholder images at any size with colors and text. Download as PNG or copy the data URI instantly in your browser.

Generate QR codes instantly from any URL or text. Choose size, error correction, and colors. Download as PNG for free.

Generate random numbers within a range with optional uniqueness.

Generate customisable SVG wave dividers for web pages.

Generate v4 UUIDs in bulk, with one click. Copy individually or all at once.

Calculate your exact age in years, months, and days from your date of birth.

Estimate the electricity use and cost of running an air conditioner.

Resize width or height while preserving the original aspect ratio.

Calculate your Body Mass Index (BMI) in metric or imperial units instantly.

Estimate daily calorie needs and macronutrient targets by goal.

Calculate compound interest over time with a growth chart

Calculate the exact time remaining until a selected date and time.

Convert between world currencies with static exchange rates.

Calculate the exact number of days, weeks, months, and years between two dates.

Calculate dew point and understand how humid the air will feel.

Calculate sale price, savings amount, and effective discount percentage instantly.

Estimate download time from file size and connection speed.

Estimate electricity cost from wattage, hours used, and rate per kWh.

Calculate the hourly rate needed to hit a desired annual income.

Estimate trip fuel cost from distance, efficiency, and price

Calculate your GPA from course grades and credit hours instantly.

Estimate grilling time and safe target temperature for popular summer foods.

Calculate max heart rate and aerobic/anaerobic training zones.

Calculate how hot it really feels using air temperature and relative humidity.

Convert hourly rate to annual/monthly salary and vice versa.

Estimate ideal weight using Devine, Robinson, Miller, and Hamwi formulas.

Calculate return on investment as a percentage and absolute gain.

Calculate monthly payments, total interest, and payoff date for any loan or mortgage. Supports extra payments.

Monthly payment, total interest, and amortization breakdown.

Calculate how many gallons of paint you need from room dimensions.

Estimate how much ice to buy for summer drinks, coolers, and outdoor parties.

Calculate percentages, percentage change, and increase/decrease instantly.

Check how long perishable food can safely remain outdoors in warm weather.

Focus timer with configurable work and break intervals using the Pomodoro Technique

Estimate pool water volume in gallons and liters from its dimensions.

Estimate due date from last menstrual period or conception date.

Paste any text to instantly estimate how long it takes to read.

Scale ingredient quantities for a different number of servings.

Calculate resistance and tolerance from resistor color bands.

Project retirement savings with contributions and growth rate.

Estimate the shade cast by an umbrella, tree, or structure from the sun angle.

Find the best times to wake up based on 90-minute sleep cycles.

Find how long you can safely sit in the sun to tan without burning, based on your skin type and UV index.

Estimate how much sunscreen to pack for a group, trip, or beach day.

Calculate tip amount, total bill, and per-person split instantly.

Understand UV risk and get practical sun-protection guidance for your skin type.

Add or remove VAT and sales tax from any price instantly.

Calculate your recommended daily water intake based on weight and activity level.

Convert text between uppercase, lowercase, title case, camelCase, snake_case, and more.

Count characters with platform limits for Twitter, SMS, meta descriptions, and more

Remove repeated lines with case and whitespace options.

Find and replace text with plain or regex patterns

Sort lines alphabetically, numerically, by length, or randomly.

Translate text to Morse code and back

Convert any number to its written English equivalent.

Check whether a word or phrase is a palindrome.

Intelligently capitalise the first letter of each sentence.

Convert any string into a clean, URL-friendly slug.

Compare two blocks of text and highlight added, removed, and unchanged lines.

Repeat any text a chosen number of times with a custom separator.

Extract the most important sentences from a block of text.

Remove extra spaces, trim lines, collapse blank lines, and clean up whitespace in any text.

Count words, characters, sentences, paragraphs, and reading time instantly.