All tools

Current time across major cities.

Convert any time between time zones.

Find a good meeting time across multiple zones.

Count down to any future moment.

Precise stopwatch with laps.

Convert between Unix time and human-readable dates.

Convert local time to UTC and back.

Calculate the difference between two dates.

Check if a time zone is in daylight saving time.

Convert between metric and imperial length units — metres, kilometres, centimetres, feet, inches, yards, miles and nautical miles.

Convert mass and weight between kilograms, grams, pounds, ounces, stones and tonnes.

Convert temperatures between Celsius, Fahrenheit and Kelvin in real time.

Convert speeds between km/h, mph, m/s, ft/s and knots.

Convert volumes between litres, gallons, cups, pints and fluid ounces.

Convert between bits, bytes, MB, GB, TB and PB.

Calculate width or height for any aspect ratio — 16:9, 4:3, 1:1, 21:9 and custom values.

Convert between pixels, rem and em units for CSS layouts.

Convert colour values between HEX, RGB and HSL with a built-in WCAG contrast checker.

Format, validate and minify JSON.

Encode and decode Base64 strings instantly.

Percent-encode and decode URL components.

Generate v4 UUIDs with one click.

SHA-1, SHA-256, SHA-384 and SHA-512.

Test JavaScript regular expressions live.

Decode JSON Web Tokens (header & payload).

Compare two text blocks line by line.

Pretty-print and indent HTML.

Live render Markdown to HTML.

Estimate token counts for LLM prompts.

Clean up and format AI prompts.

Strip Markdown formatting to plain text.

Remove filler words and timestamps.

Normalize whitespace, dashes and quotes.

Fill {{variables}} in prompt templates.

Split long text into LLM-friendly chunks.

Strip SRT/VTT cues to clean text.

Fix common OCR artifacts and broken lines.

Word, character and reading-time counter.

Live character count with limits.

Estimate reading time for any text.

Score headlines for length, power and clarity.

UPPER, lower, Title, camelCase, snake_case, kebab-case.

Convert text into clean URL slugs.

Remove duplicate lines from any list.

Generate placeholder Lorem Ipsum text by paragraphs, sentences or words.

Reverse a string by characters, words or lines.

Sort lines alphabetically, numerically or randomly.

Count how often each word appears in a text.

Strip newlines and join paragraphs into a single line.

Prefix every line with a sequential number.

Replace text with optional case-sensitive and regex modes.

Repeat any text or pattern N times with an optional separator.

Capitalise titles using AP, Chicago and sentence-case rules.

Trim, collapse and normalise whitespace and tabs.

Strip comments and whitespace from CSS for production.

Quickly minify JavaScript by removing comments and whitespace.

Compress HTML by removing comments and unnecessary whitespace.

Format and indent SQL queries for readability.

Encode and decode HTML entities like & and <.

Convert Markdown to clean, copyable HTML.

Convert a JSON array of objects into a CSV table.

Parse CSV text into a JSON array of objects.

Search and look up the meaning of any HTTP status code.

Inspect the browser, OS and device behind any user-agent string.

Convert numbers between binary, octal, decimal and hexadecimal.

Convert Celsius to Fahrenheit instantly with formulas, examples, and common temperature conversions.

Convert Fahrenheit to Celsius instantly. See the formula, real examples and the most-searched °F → °C conversions.

Convert kilograms (kg) to pounds (lbs) instantly with formula, real examples and a common-values reference table.

Convert pounds (lbs) to kilograms (kg) instantly with formula, examples and common values.

Convert miles to kilometres instantly. Formula, real examples and a common-distance reference.

Convert kilometres to miles instantly with formula, examples and a quick reference table.

Convert centimetres to inches instantly with formula, examples and a clear reference.

Convert inches to centimetres instantly. Includes formula, real examples and a reference table.

Convert litres to US and Imperial gallons instantly with formulas, examples and a reference table.

Work out percentages, percentage of a number, percentage change and reverse percentages.

Calculate restaurant tip, total and per-person split for any bill.

Calculate Body Mass Index (BMI) from height and weight in metric or imperial units.

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

Estimate monthly mortgage payments from loan amount, rate, term and payment frequency.

Calculate monthly loan payments and total interest for any fixed-rate loan.

Project savings growth with compound interest, regular contributions and any compounding frequency.

Calculate simple interest, total repayment and interest earned over time.

Work out sale price and savings from a percentage discount.

Calculate sales tax, VAT or GST for any country — US, UK, EU, Australia, Canada and more — at any rate.

Generate strong random passwords with custom length and character sets.

Generate random integers in any range, with optional uniqueness and count.

Roll one or many dice (d4, d6, d8, d10, d12, d20, d100) with totals.

Flip a virtual coin once or many times and see the heads/tails split.

Generate random colors in HEX, RGB and HSL with a click.

Pick one or more random names from a list — for raffles, draws, and team picks.

Shuffle any list of items into a random order.

Generate random linear-gradient CSS with copyable code.

Generate cryptographically strong secret keys in hex, base64 or base64url.

Generate random letters from A–Z, with options for case and count.

Convert between world currencies using live mid-market exchange rates.

Convert between Bitcoin, Ethereum and major cryptocurrencies in any fiat currency.

Calculate compound annual growth rate (CAGR) and final value of any investment.

Calculate how purchasing power changes over time at any inflation rate.

Convert between gross and net salary at any tax rate, with annual, monthly and weekly breakdowns.

Count working days (Monday–Friday) between two dates.

Find the ISO 8601 week number for any date.

Estimate daily calorie needs (TDEE) using the Mifflin-St Jeor equation.

Calculate daily protein target in grams based on bodyweight and goal.

Estimate daily water needs based on bodyweight and activity.

Convert running pace between min/km and min/mile, and project finish times.

Estimate body fat percentage using the US Navy method.

Convert cups, tablespoons, teaspoons, millilitres and grams.

Convert shoe sizes between US, UK, EU and JP for men, women and kids.

Convert ring sizes between US, UK, EU and inner diameter / circumference.

Convert clothing sizes between US, UK, EU letter and numeric systems.

Estimate trip fuel cost from distance, vehicle consumption and fuel price.

Convert fuel economy between MPG (US), MPG (UK), L/100km and km/L.

Calculate a baby's age in weeks, months and days from their birthdate.

Add, subtract, multiply and divide fractions with automatic simplification.

Evaluate math expressions with sin, cos, tan, log, sqrt and constants.

Solve A:B = C:? proportions and simplify ratios to lowest terms.

Calculate mean, median, mode, range and standard deviation from a list of numbers.

Calculate density, mass or volume from any two known values.

Solve for voltage, current, resistance or power given any two values.

Calculate the output voltage of a two-resistor voltage divider.

Convert frequencies between Hz, kHz, MHz, GHz and period in seconds.

Convert torque between Newton-metres, pound-feet and kilogram-force-metres.

Convert force between Newtons, pound-force, kilogram-force and dynes.

Calculate pixel density, print size and dimensions for any DPI.

Calculate target width, height and aspect ratio when resizing images.

Estimate API cost for GPT, Claude, Gemini and other LLMs from prompt and completion tokens.

See how much text fits in GPT, Claude, Gemini and other LLM context windows.

Compose a structured system prompt with role, goals, constraints, format and examples.

Build a Midjourney prompt with subject, style, lighting, camera, aspect ratio and parameters.

Build positive and negative prompts for Stable Diffusion / SDXL with weight syntax helpers.

Generate a strong negative prompt for Stable Diffusion to avoid common image defects.

Tighten an LLM prompt — strip filler, clarify the ask, add structure for better results.

Build a few-shot prompt with input/output pairs in plain, JSON or messages format.

Wrap a question with chain-of-thought scaffolding to coax step-by-step reasoning.

Build a detailed character roleplay prompt with persona, voice, setting and rules.

Generate a random user persona — name, age, role, goals, pain points — for product testing.

Extract relevant hashtags from any text or topic, formatted for Instagram, Twitter, LinkedIn or TikTok.

Generate 10 SEO-optimised page title variants from a topic and target keyword.

Estimate cost of embedding a corpus with OpenAI, Cohere, Voyage and other providers.

Compare two prompt versions side-by-side with word-level highlighting.

Convert meters to feet instantly with formula, examples and a full reference table.

Convert feet to metres instantly with formula and reference values.

Convert feet to inches with formula and a quick reference table.

Convert inches to feet (and remaining inches) instantly.

Convert millimetres to inches with formula and reference values.

Convert inches to millimetres with formula and reference table.

Convert yards to metres instantly with formula and examples.

Convert metres to yards instantly with formula and a reference table.

Convert grams to ounces instantly for cooking, post and shipping.

Convert ounces to grams with formula and a quick reference.

Convert stones (and pounds) to kilograms.

Convert kilograms to stones (UK bodyweight unit).

Convert sq ft to sq m for floor plans and real estate.

Convert m² to sq ft for floor area and real estate.

Convert acres to hectares for land area.

Convert ml to fluid ounces (US) instantly.

Convert US fl oz to ml for recipes and cocktails.

Convert US cups to millilitres for cooking and baking.

Convert ml to US cups for recipes and baking.

Convert tablespoons (US) to millilitres.

Convert hours to minutes instantly.

Convert minutes to hours and decimal hours.

Convert seconds to minutes (decimal).

Convert minutes to seconds.

Convert days to weeks (decimal).

Convert weeks to days.

Convert megabytes to gigabytes (decimal SI, 1 GB = 1000 MB).

Convert gigabytes to megabytes (decimal SI).

Convert kilobytes to megabytes (SI).

Convert gigabytes to terabytes (SI).

Convert PSI (pounds per square inch) to bar — tyre and gas pressure.

Convert bar to PSI for tyre and gas pressure.

Convert kilopascals to PSI.

Convert watts to kilowatts.

Convert kilowatts to watts.

Convert watts to mechanical horsepower (hp).

Convert mechanical horsepower to watts.

Convert joules to (small) calories — physics, not food.

Convert calories to joules.

Convert CSS rem units to pixels at any base font size.

Calculate stock profit/loss, return % and total proceeds from buy price, sell price, share count and fees.

Calculate dividend yield % and annual dividend income from share price and dividend per share.

Calculate crypto trade profit/loss and ROI from buy price, sell price, amount and exchange fees.

Model dollar-cost averaging into a stock, ETF or crypto: average cost, total invested and final value.

Calculate price-to-earnings ratio and earnings yield from share price and EPS.

Calculate new share count and adjusted price after a forward or reverse stock split (e.g. 4:1, 1:10).