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Free Online Tools: Calculators, Converters & Generators

291 free online tools: QR codes, JSON formatting, image conversion and calculators. Search by task and use a tool without signing up.

Free online tools

Find a tool for the task in front of you. Format data, create QR codes, convert files or calculate costs. Search below or browse a category; no account required.

291 tools

Shortcuts to create, convert and calculate.

Generators

Create QR codes, secure passwords, UUIDs, hashes, and more with our free generator tools.

Mailto Link Generator

Generate HTML mailto links with pre-filled subject, body, CC, and BCC fields

RSS Feed Generator

Create a valid RSS 2.0 XML feed from your blog posts or content items. Free, no signup required.

ICS File Generator

Create calendar event files for Google Calendar, Apple Calendar, and Outlook

Chord Progression Generator

Generate chord progressions in any key and scale mode

Online Metronome

Free online metronome with adjustable BPM, time signatures, and tempo markings for music practice

Online Tone Generator

Generate pure audio tones at any frequency (20 Hz–20 kHz) — sine, square, sawtooth and triangle waves. Free, runs in your browser.

Ical Event Generator

A free browser-based ical event generator for ics file generator and ical event generator.

Passphrase Generator

A free browser-based passphrase generator for passphrase generator and diceware generator.

Mock Data Generator

Generate fake test data with realistic names, emails, phones, and more. Export as JSON, CSV, or SQL INSERT.

QR Code Generator

Create custom QR codes with colors and different sizes

Password Generator

Generate strong, secure passwords with custom options

UUID Generator

Generate unique identifiers (UUID v1 & v4)

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-512 hashes

Lorem Ipsum Generator

Generate placeholder text for designs and mockups

Slug Generator

Convert text to URL-friendly slugs for SEO optimization

Cron Expression Generator

Build and validate cron expressions with a visual editor

Placeholder Image Generator

Generate placeholder images with custom dimensions and colors

Invoice Generator

Create professional invoices for your business or freelance work

Privacy Policy Generator

Generate a privacy policy for your website or app

Random Number Generator

Generate random numbers within a range

Bulk Password Generator

Generate multiple passwords at once

Random Color Generator

Generate random color palettes

Random Word Generator

Generate random English words by category — nouns, verbs, adjectives, adverbs

Dummy Text Generator

Generate placeholder text in different styles

Barcode Generator

Create barcodes in various formats

WiFi QR Code Generator

Generate QR codes for WiFi network sharing

vCard Generator

Create digital contact cards

Terms of Service Generator

Generate terms of service for your website

Cookie Policy Generator

Generate a cookie consent policy

README Generator

Create professional README files for GitHub

Gitignore Generator

Generate .gitignore files for any project

License Generator

Generate open source license files

Changelog Generator

Create formatted changelogs

Email Signature Generator

Create professional email signatures

Lorem Pixel Generator

Generate placeholder images with Lorem Picsum

Markdown Table Generator

Create markdown tables visually

HTML Table Generator

Generate HTML table code visually

Nginx Config Generator

Generate Nginx configuration files

Docker Compose Generator

Build docker-compose.yml files visually

ENV File Generator

Create .env files for your projects

Color Pallete Generator

Color Pallete Generator - Free online tool

Coin Flipper

Flip a virtual coin online — heads or tails — with real-time statistics and flip history.

Random Picker

Pick random names or items from a list online — one click, instant result

Design Tools

Color palette generators, CSS gradient creators, and visual design utilities for web designers.

Hex Color Opacity Calculator

Convert a hex color code to hex8 (RRGGBBAA), rgba(), and hsla() with custom opacity

CSS Gradient Border Generator

Generate CSS gradient borders with live preview. Supports border-radius using the background-clip technique.

PPI Calculator

Calculate screen pixel density (PPI / pixels per inch) from display resolution and diagonal screen size

CSS Cubic Bezier Generator

Create custom CSS cubic-bezier() easing functions with a visual curve editor and animation preview

Z-Index Calculator

Visualize CSS z-index stacking order and resolve layering conflicts between elements

CSS Cubic Bezier Generator

Create custom cubic-bezier easing functions visually for CSS animations and transitions

Neumorphism Generator

Create soft UI (neumorphism) CSS effects with live preview

Color Palette Generator

Create, customize, and export beautiful color palettes for your design projects

CSS Gradient Generator

Create beautiful CSS gradients with live preview

Box Shadow Generator

Create CSS box shadows with visual editor

Color Converter

Convert colors between HEX, RGB, HSL, HSV, and CMYK formats

Color Contrast Checker

Check color contrast ratios for WCAG accessibility compliance

Color Picker

Pick colors from a visual palette

CSS Grid Generator

Visual CSS Grid layout builder

Flexbox Playground

Interactive CSS Flexbox visualizer

Text Shadow Generator

Create CSS text shadow effects

Border Radius Generator

Visual border-radius editor

Glassmorphism Generator

Create frosted glass CSS effects

Gradient Text Generator

Create colorful gradient text with CSS

CSS Animation Generator

Create CSS keyframe animations visually

Favicon Generator

Generate favicons from text or images

OG Image Generator

Create Open Graph images for social sharing

Font Pair Suggester

Find perfect font combinations

Tailwind Color Generator

Generate custom Tailwind CSS color scales

Pixel to REM Converter

Convert between px and rem units

Em to Px Converter

Convert em, rem, and px CSS units instantly

CSS Clamp Calculator

Generate CSS clamp() values for fluid, responsive typography and spacing

Developer Tools

JSON formatters, regex testers, diff checkers, and essential tools for software developers.

JSONL / NDJSON Formatter & Validator

Validate and format JSON Lines (JSONL / NDJSON) data online — line-by-line error reporting, compact and pretty-print modes

ESM ↔ CommonJS Converter

Convert between ES modules and CommonJS syntax online

Semver Bump Calculator

Calculate major, minor, and patch version bumps for semantic versioning

Iframe Generator

Generate iframe HTML embed code with full attribute control — width, height, sandbox, referrer policy and more

Keycode Tester

A free browser-based keycode tester for javascript keycode and keycode tester.

YAML Formatter

Format, validate and minify YAML online. Fix YAML syntax errors instantly in your browser — no signup required.

Indent Converter

Convert between tabs and spaces and normalize code indentation

KeyCode Finder

Press any key to instantly see its JavaScript event properties: event.key, event.code, keyCode, and Unicode code point

SemVer Calculator

Check if a version satisfies a semantic versioning range — decode ^, ~, and comparison operators online

SVG to React Component

Convert SVG markup into a ready-to-use React component. Transforms class→className, kebab-case props→camelCase, and inline styles automatically.

JWT Decoder

Decode JSON Web Tokens securely in your browser

JWT Encoder

Create and sign JSON Web Tokens with custom payloads

JSON Formatter

Format, validate, and beautify JSON data

Regex Tester

Test and debug regular expressions in real-time

Diff Checker

Compare two texts and highlight the differences

Markdown Preview

Write and preview Markdown in real-time

Meta Tag Generator

Generate complete meta tags for SEO and social previews.

Website Speed Test

Check loading speed and core performance metrics for any URL.

Keyword Density Checker

Check keyword density to optimize your content for search engines

SERP Snippet Preview

Preview Google result snippets and validate title/meta description length.

Robots.txt Generator

Generate robots.txt rules to control crawling and include sitemap directives.

Canonical URL Checker

Validate canonical URLs and catch common indexing mistakes.

Hreflang Generator

Create hreflang tags for multilingual SEO and validate locale mappings.

CSS Minifier

Minify and compress CSS code to reduce file size

JavaScript Minifier

Minify JavaScript code for production

HTML Minifier

Compress HTML markup by removing whitespace

SQL Formatter

Format and beautify SQL queries

XML Formatter

Format and validate XML documents

Chmod Calculator

Calculate Unix file permissions

Open Graph Preview

Preview how your page looks on social media

Twitter Card Preview

Preview Twitter card metadata

UTM Link Builder

Build UTM tracking parameters for campaigns

Schema Markup Generator

Generate JSON-LD structured data for SEO

FAQ Schema Generator

Create FAQ schema markup for rich snippets

HTTP Status Codes Reference

Complete HTTP status codes reference with descriptions — search 60+ codes from 1xx to 5xx. Free and instant.

CSS Specificity Calculator

Calculate CSS selector specificity

Subresource Integrity Generator

Subresource Integrity Generator - Free online tool

YAML Validator

Free online YAML validator. Paste your YAML and instantly check syntax, see error line numbers, and preview parsed structure as JSON. No signup needed.

JSON Validator

Validate and format JSON online — instant syntax checking

Chmod Converter

Chmod Converter - Free online tool

Text & Writing

Word counters, case converters, and text manipulation tools for writers and content creators.

Palindrome Checker

Instantly check if text is a palindrome, with options to ignore case, spaces, and punctuation.

Syllable Counter

Count syllables in any word or text online. Line-by-line analysis, haiku checker, and per-word breakdown.

Leet Speak Generator (1337)

Convert text to leet speak (1337). Choose from 3 levels of l33tness for gaming profiles, memes, and online messages.

Anagram Solver

Find all words that can be formed from your letters — free word unscrambler online

Remove Line Breaks

Remove or replace line breaks from text instantly. Paste text from PDFs, emails or documents and clean it up.

Vigenere Cipher

A free browser-based vigenere cipher for vigenere cipher and vigenere cipher decoder.

Word Counter

Count words, characters, sentences, and paragraphs in your text

Case Converter

Convert text between different case formats instantly

Character Counter

Count characters, words, and sentences

Text Repeater

Repeat text multiple times

Remove Duplicate Lines

Remove duplicate lines from text

Sort Lines

Sort text lines alphabetically or numerically

Find and Replace

Find and replace text with regex support

Whitespace Remover

Remove extra whitespace from text

Line Counter

Count lines in text or code

Reading Time Calculator

Estimate reading time for any text

Morse Code Translator

Translate text to Morse code and back

Caesar Cipher Encoder & Decoder

Encode and decode text using the Caesar cipher shift. Supports ROT13 and all 26 shift values.

Bold Text Generator

Generate bold, italic, and 10 Unicode text styles for Instagram, Twitter & social media. Copy and paste instantly.

Readability Score Checker

Check Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, and ARI readability scores of any text — free, instant, no signup.

Word Frequency Counter

Analyze word frequency in any text — see which words appear most often with counts and percentages

NATO Phonetic Alphabet

Convert any text to NATO phonetic alphabet. Instantly spell out words as Alpha, Bravo, Charlie and more — with a clickable reference table.

List Format Converter

Convert a column of items to comma-separated list, SQL IN clause, JSON array, and more formats online

Converters & Encoders

Convert between formats: Base64, URL encoding, timestamps, units, and image formats.

Number Formatter

Format numbers with locale-aware separators, currency symbols, and compact notation

Markdown to JSON Converter

Convert Markdown tables, lists, and YAML front matter to JSON instantly in your browser. Free, no signup required.

ISBN Validator

Validate ISBN-10 and ISBN-13 barcodes, check the check digit, and convert between formats

Hex to Tailwind Color Finder

Find the nearest Tailwind CSS color for any hex color

Image Converter

Convert images between PNG, JPG, and WebP formats

Base64 Encoder/Decoder

Encode and decode text to Base64 format

URL Encoder/Decoder

Encode and decode URLs for safe transmission

HTML Encoder/Decoder

Encode and decode HTML entities for safe display

Timestamp Converter

Convert between Unix timestamps and human dates

Unit Converter

Convert between different units of measurement

URL Shortener

Turn long URLs into short, shareable links instantly

CSV/JSON Converter

Convert between CSV and JSON formats easily

QR Code Decoder

Scan and decode QR codes from images

JSON to TypeScript Converter

Convert JSON objects to TypeScript interface or type definitions

Markdown to HTML Converter

Convert Markdown text to HTML with live preview

Number Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal

Text Extractor (OCR)

Extract text from images using AI-powered OCR

YAML to JSON Converter

Convert YAML to JSON online — validate YAML syntax and get formatted JSON output instantly.

SVG to PNG Converter

Convert SVG files to PNG images

Image Resizer

Resize images to exact dimensions

Text to Binary

Convert text to binary and back

Text to ASCII Art

Convert text to ASCII art

Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals back to numbers instantly

Bytes Converter

Convert between bytes, KB, MB, GB, TB

Temperature Converter

Convert between Celsius, Fahrenheit, and Kelvin

Scientific Notation Converter

Convert between decimal and scientific notation. Supports E notation and engineering notation.

HEX to RGB Converter

Convert HEX color codes to RGB values

Time Zone Converter

Convert time between different time zones

Length Converter

Convert between inches, cm, meters, feet

Weight Converter

Convert between kg, lbs, oz, grams

Speed Converter

Convert between mph, km/h, m/s, knots

Area Converter

Convert between sq meters, sq feet, acres, hectares

Volume Converter

Convert between liters, gallons, cups, ml

Energy Converter

Convert between joules, calories, BTU, kWh

JSON to CSV Converter

Convert JSON data to CSV format

JSON to XML Converter

Convert JSON data to XML format

CSV to SQL Converter

Convert CSV data to SQL INSERT statements

JSON to Go Struct

Convert JSON to Go struct definitions

JSON to Python Dict

Convert JSON to Python dictionary

cURL to Code Converter

Convert cURL commands to code in any language

JSON to YAML Converter

Convert JSON to YAML format online — paste JSON and get clean YAML output instantly.

Image to Base64 Converter

Convert images to Base64 encoded strings for HTML, CSS, and APIs

Base64 to Image Converter

Decode Base64 strings to images — preview, inspect metadata, and download

Image Compressor

Compress images without losing quality

Biorhythm Tracker

Track your medication cycle and energy levels

Epoch/Unix Timestamp Converter

Convert between epoch timestamps and dates

Cron To Human

Cron To Human - Free online tool

HTML Entity Converter

Encode and decode HTML entities instantly

Number to Words Converter

Convert any number to written English words instantly — supports decimals, negatives, and currency

Hex Text Converter

Convert text to hexadecimal and hex to text online. Supports Unicode characters, multiple separators, and uppercase or lowercase output. Free, instant, no signup.

Military Time Converter

Convert between 12-hour AM/PM and 24-hour military time format instantly — with quick reference chart

Binary to Text Converter

Convert binary code to readable text — or encode text into binary. Supports space-separated and continuous binary strings.

Calculators

BMI calculator, age calculator, percentage calculator, and budget planning tools.

Recipe Scaler

Scale recipe ingredient quantities up or down for any number of servings instantly in your browser

Standard Deviation Calculator

Calculate standard deviation, variance, mean, median, mode, quartiles, and more — with step-by-step breakdown

Speed Distance Time Calculator

Calculate speed, distance, or time — enter any two values to solve for the third

Flooring Calculator

Calculate how much flooring you need for any room, including waste factor and cost estimate

Heat Index Calculator

Calculate the apparent "feels like" temperature from air temperature and relative humidity using the NWS Rothfusz equation. Shows heat danger levels.

Free Fall Calculator

Calculate free fall time, distance, and velocity for any planet gravity

APR to APY Calculator

Convert between Annual Percentage Rate and Annual Percentage Yield with compounding frequency support

NPV Calculator

Calculate net present value (NPV) and IRR from cash flows and a discount rate

Rule of 72 Calculator

Estimate how long it takes to double an investment using the Rule of 72

Frequency to Wavelength Calculator

Convert frequency to wavelength and back — supports Hz to THz and nm to km with EM spectrum region

Sunrise & Sunset Calculator

Calculate sunrise, sunset, golden hour, and twilight times for any location and date

Sales Tax Calculator

Calculate sales tax amount and total price — or remove tax from a total to find the pre-tax price. Includes common US state and international tax rate presets.

Slope Calculator

Calculate slope, distance, midpoint and line equation between two coordinate points

Tap Tempo BPM Calculator

Tap to find the BPM of any song or rhythm — see tempo name and note durations

Moon Phase Calculator

Calculate the moon phase for any date — see illumination %, lunar cycle progress, and upcoming new and full moon dates

Heart Rate Calculator

Calculate your maximum heart rate and 5 training zones by age — with Karvonen method support

Ohm's Law Calculator

Calculate voltage, current, resistance, and power using Ohm's Law. Enter any two values to solve the circuit.

Video Bitrate Calculator

Calculate the optimal video bitrate for streaming and encoding

Dew Point Calculator

Calculate dew point, heat index, and humidity comfort level from temperature and relative humidity. Instant, free, no signup.

Wind Chill Calculator

Calculate wind chill temperature and frostbite risk using the NOAA formula

Pixel Density Calculator (PPI)

Calculate pixels per inch (PPI) for any screen resolution and size

One Rep Max Calculator

Calculate your one rep max (1RM) using 5 proven formulas — then get a full training table with weights for every intensity level

Golden Ratio Calculator

Calculate golden ratio segments, golden rectangles, and check how close any two values are to phi (1.618).

Ohm's Law Calculator

Calculate voltage, current, resistance, and power using Ohm's Law. Instant V=IR solver for electronics and electrical engineering.

Resistor Color Code Calculator

Decode 4-band and 5-band resistor color codes to find resistance value and tolerance — free online tool

Prime Factorization Calculator

Find prime factors of any number. Shows prime factorization, exponential notation, and all divisors instantly.

BPM Calculator

Find the BPM of any song by tapping to the beat

Simple Interest Calculator

A free browser-based simple interest calculator for simple interest calculator and calculate simple interest.

FIRE Calculator

Calculate your Financial Independence Retire Early number and years to freedom

Triangle Calculator

Solve any triangle — enter any 3 known values to calculate all sides, angles, area, and properties

Net Worth Calculator

Calculate your net worth by adding up all assets and subtracting total liabilities

Combination & Permutation Calculator — nCr and nPr

Calculate combinations nCr and permutations nPr instantly with step-by-step factorial breakdown. Free online calculator.

Break-Even Calculator

Calculate break-even point in units and revenue for any business

Haversine Calculator

A free browser-based haversine calculator for haversine calculator and distance between coordinates.

Percentage Calculator

Calculate percentages, percentage change, tips, and more

Age Calculator

Calculate your exact age in years, months, days, and more

BMI Calculator

Calculate your Body Mass Index and check your weight category

50/30/20 Budget Calculator

Calculate your budget using the 50/30/20 rule for financial planning

Tip Calculator

Calculate tips and split bills between friends

Pomodoro Timer

Stay focused with the Pomodoro technique timer

Aspect Ratio Calculator

Calculate and convert aspect ratios for images and video

Loan Calculator

Calculate monthly payments and total interest

Annuity Calculator

Calculate present value and future value of annuity payments with amortization schedule

Compound Interest Calculator

Calculate compound interest growth over time

CAGR Calculator

Calculate compound annual growth rate from start and end values

Profit Margin Calculator

Calculate profit margins and markups

Discount Calculator

Calculate sale prices and savings

Salary Calculator

Convert between hourly, monthly, and yearly salary

VAT/Tax Calculator

Calculate VAT, sales tax, and price with tax

ROI Calculator

Calculate return on investment

Debt-to-Income Ratio Calculator

Calculate your debt-to-income (DTI) ratio to see if you qualify for a mortgage or loan

Markup Calculator

Calculate markup percentage and selling price

Mortgage Calculator

Calculate monthly mortgage payments

Date Difference Calculator

Calculate days between two dates

Online Stopwatch

Simple stopwatch with lap times

Countdown Timer

Set a countdown timer for any duration

World Clock

View current time across different time zones

GPA Calculator

Calculate your grade point average

Fuel Cost Calculator

Calculate fuel costs for trips

Electricity Cost Calculator

Estimate electricity costs for appliances

Screen Resolution Calculator

Calculate PPI, aspect ratios, and scaling

Retirement Calculator

Calculate how much you need to retire and project your savings growth

Calorie Calculator

Calculate your daily calorie needs (BMR & TDEE) based on age, height, weight, and activity level.

Sleep Cycle Calculator

Calculate ideal bedtime and wake-up times based on 90-minute sleep cycles

Water Intake Calculator

Calculate how much water you should drink per day based on weight, activity level, climate, pregnancy, and breastfeeding

Network Subnet Calculator

Network Subnet Calculator - Free online tool

Bandwidth Calculator

Bandwidth Calculator - Free online tool

Uptime Calculator

Calculate allowed downtime for any uptime SLA percentage — 99.9%, 99.99%, 99.999% and more

Split Bill Calculator

Split Bill Calculator - Free online tool

Grade Calculator

Grade Calculator - Free online tool

Scientific Calculator

Scientific Calculator - Free online tool

Statistics Calculator

Calculate mean, median, mode, standard deviation, and more

Probability Calculator

Calculate probability of events, compound probability, combinations, and permutations

Binary Calculator

Free binary calculator — add, subtract, multiply, divide and apply bitwise operations (AND, OR, XOR, NOT) on binary numbers. Results shown in binary, decimal, hex, and octal.

Hex Calculator

Hexadecimal arithmetic and bitwise operations with base conversion

Fraction Calculator

Fraction Calculator - Free online tool

Truth Table Generator

Truth Table Generator - Free online tool

Fibonacci Calculator

Fibonacci Calculator - Free online tool

Gcd Lcm Calculator

Gcd Lcm Calculator - Free online tool

Quadratic Formula Calculator

Solve quadratic equations ax²+bx+c=0 with step-by-step solution, discriminant, and roots

Area Calculator

Calculate the area of circles, rectangles, triangles, trapezoids, ellipses, and more

Body Fat Calculator

Calculate your body fat percentage using the US Navy method

Macro Calculator

Calculate your daily protein, fat, and carbohydrate targets in grams from any calorie goal

Typing Speed Test

Test your typing speed and accuracy online for free

A/B Test Calculator

Calculate statistical significance for your A/B tests instantly

Work Days Calculator

Work Days Calculator - Free online tool

Mortgage Amortization Calculator

Generate a complete mortgage amortization schedule with monthly and yearly payment breakdown

Spending Projection

Track your spending and income with a visual dashboard to project your financial future

Life in Weeks

See your whole life as a grid of weeks — one square per week, filled up to today

Meeting Cost Calculator

Price any meeting by the people in the room — per meeting, per year, and in hours burned

Caffeine Half-Life Calculator

Plot how much caffeine is still in your system at bedtime, drink by drink

AI Tools

AI-powered tools for content creation, resume writing, and professional branding.

About these tools

Do I need an account?

No. Choose a tool, enter the required information and use the result without signing up.

Does my data leave the browser?

Many tools process data locally. AI features and external lookups may send the necessary input to a service. Check the tool instructions and privacy policy before using sensitive information.

Which tool should I choose?

Use converters to change formats, generators to create codes or text, and calculators to compare values. Search by a tool name or the task you want to complete.