ToolLab
ToolLab
Use practical calculators, converters, developer tools, image tools, PDF tools, and finance tools online.
Popular Tools
JSON Formatter
Format, validate, and beautify JSON instantly. Paste raw JSON and get clean, indented output in one click.
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to plain text instantly. No installation required.
URL Encoder / Decoder
Encode special characters in URLs or decode percent-encoded strings back to readable text. Fast and free.
Image Compressor
Compress JPEG and PNG images online without losing quality. Reduce file size instantly in your browser.
PDF Merger
Merge 2 to 10 PDF files into a single document. Upload your PDFs and download the combined file instantly.
QR Code Generator
Generate QR codes for URLs, text, or any content instantly. Download as PNG with one click.
Available tools
Developer Tools
32Chmod Calculator
Calculate Unix file permissions visually. Click checkboxes to set read/write/execute for owner, group, and others. Shows octal and symbolic notation.
CSS Specificity Calculator
Calculate CSS selector specificity and understand which styles take precedence. Supports ID, class, attribute, pseudo-class, element, and pseudo-element selectors.
CSS Unit Converter
Convert between CSS units: px, rem, em, pt, vw, vh. Set custom base font size and viewport width.
JSON Path Tester
Test JSONPath expressions against JSON data. Supports dot notation, array indexing, and wildcard selectors.
JSON to TypeScript
Convert JSON objects to TypeScript interfaces and type definitions instantly. Supports nested objects, arrays, optional fields, and union types.
JSON Formatter
Format, validate, and beautify JSON instantly. Paste raw JSON and get clean, indented output in one click.
XML Formatter & Validator
Format, prettify, and validate XML online. Instantly beautify XML with proper indentation. Free online XML formatter.
SQL Formatter / Beautifier
Format and beautify SQL queries online. Automatically capitalize keywords and add line breaks. Free SQL formatter.
CSS Gradient Generator
Create beautiful CSS gradients online. Generate linear, radial, and conic CSS gradients with a live preview. Free CSS gradient tool.
CSS Box Shadow Generator
Create and preview CSS box shadows with live preview. Adjust offset, blur, spread, color, and inset. Copy the CSS code instantly.
UUID Generator
Generate random UUID v4 identifiers instantly. Copy single or bulk UUIDs for use in databases, APIs, and applications.
Unicode Converter
Convert characters to Unicode codepoints and vice versa. See UTF-8, HTML entity, CSS escape, and more for any character.
CSS / JS / HTML Minifier
Minify CSS, JavaScript, and HTML online. Remove comments and whitespace to reduce file size. Free code minifier tool.
String Escape / Unescape
Escape and unescape strings for JSON, HTML, URL encoding, and Python. Free online string escape tool.
Color Contrast Checker
Check color contrast ratio for WCAG 2.1 AA and AAA compliance. Live preview with foreground and background color pickers.
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to plain text instantly. No installation required.
Binary Calculator
Perform binary arithmetic and bitwise operations online. Supports ADD, SUB, MUL, AND, OR, XOR, NOT. Shows BIN, HEX, OCT results.
Credit Card Validator
Validate credit card numbers using the Luhn algorithm. Detects Visa, Mastercard, Amex, Discover. No data is stored or transmitted.
Korean SSN Decoder
Decode a Korean resident registration number (주민등록번호). Verify checksum, extract birth date, gender, and nationality info.
URL Encoder / Decoder
Encode special characters in URLs or decode percent-encoded strings back to readable text. Fast and free.
Pomodoro Timer
Boost your productivity with a Pomodoro timer. Customizable work, short break, and long break intervals. Tracks completed rounds and focus time.
JSON ↔ CSV Converter
Convert JSON to CSV or CSV to JSON instantly online. Supports arrays of objects. Free and easy.
Timestamp Converter
Convert Unix timestamps to human-readable dates or dates back to Unix timestamps. Supports UTC, KST, JST, and more.
Color Converter
Convert colors between HEX, RGB, and HSL formats instantly. Enter any color value and get all three formats.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text. Fast, free, and runs server-side.
Regex Tester
Test regular expressions against sample text instantly. Supports ignore case, multiline, and dotall flags. Free online regex tester.
JWT Decoder
Decode JWT header and payload instantly. Check token expiry. Free online JWT decoder, no signature verification.
Text Diff Checker
Compare two pieces of text and see added and removed lines highlighted. Free online text diff checker.
Cron Expression Parser
Parse a cron expression and see the next 5 scheduled run times instantly. Free online cron expression parser and explainer.
HTML Entity Converter
Encode text to HTML entities or decode HTML entities back to text instantly. Free online HTML entity converter.
Typography Scale Calculator
Generate a harmonious typographic scale using classical ratios (Perfect Fourth, Golden Ratio, Major Third, etc.). Output CSS variables and Tailwind config.
YAML to JSON Converter
Convert YAML to JSON or JSON to YAML instantly. Free online YAML JSON converter for config files and API data.
Generators
18Meta Tags Generator
Generate complete HTML meta tags including Open Graph, Twitter Card, and SEO tags. Preview how your page looks when shared on social media.
OTP / TOTP Generator
Generate time-based one-time passwords (TOTP/OTP) compatible with Google Authenticator and Authy. Enter a secret key to get a 6-digit OTP code.
Password Strength Meter
Analyze your password strength instantly. Shows entropy, crack time estimate, character type breakdown, and specific tips to make your password stronger.
Random Picker
Pick random items from a list, roll dice (D4–D100), flip a coin, or generate random numbers. Perfect for games, decisions, and giveaways.
Robots.txt Generator
Generate a robots.txt file for your website. Set crawl rules for Googlebot, Bingbot, and other search engine crawlers. Add sitemaps and disallow paths.
QR Code Generator
Generate QR codes for URLs, text, or any content instantly. Download as PNG with one click.
Random Generator
Generate random numbers, random strings, or pick random items from a list. Cryptographically secure. Free online random generator.
Lorem Ipsum Generator
Generate Lorem Ipsum placeholder text by paragraphs, sentences, or words instantly. Free online Lorem Ipsum generator.
Password Generator
Generate strong, random passwords with custom length and character options. Server-side generation using cryptographically secure randomness.
Dice Roller
Roll virtual dice online. Choose from D4, D6, D8, D10, D12, D20, or D100. Roll multiple dice with modifiers. Free online dice roller.
Barcode Generator
Generate Code 128, Code 39, EAN-13, EAN-8, UPC-A, or ISBN-13 barcodes instantly. Free online barcode generator.
Styled QR Code Generator
Generate stylish QR codes with custom foreground and background colors, logo insertion, and adjustable error correction. Download as PNG instantly.
HMAC Generator
Generate HMAC signatures with SHA-256, SHA-512, SHA-1, or MD5. Output in Hex and Base64. Free online HMAC generator.
Fake Data Generator
Generate fake test data including names, emails, phone numbers, addresses, and company names in Korean, English, and Japanese.
Password Strength Checker
Check the strength of any password instantly. Analyzes length, character variety, and common patterns. Free online password strength meter.
Coin Flip
Flip a virtual coin online. Get heads or tails results instantly. Tracks flip history and statistics for multiple tosses.
Korean Business Registration Number Validator
Validate Korean business registration numbers (사업자등록번호) using the official checksum algorithm. Instant verification.
Favicon Maker
Design a favicon with text, letters, or emoji. Customize font, colors, and rounded corners. Download as favicon.ico (16/32/48px) or PNG (512px). Free online tool.
Converters
25Color Format Converter
Convert colors between HEX, RGB, RGBA, HSL, HSLA, HSB/HSV, OKLCH, and CSS named colors. See real-time color preview and copy any format instantly.
File Size Converter
Convert file sizes between bytes, kilobytes, megabytes, gigabytes, terabytes, and more. Supports both SI (decimal) and IEC (binary) units.
HTML to Markdown Converter
Convert HTML to Markdown online. Paste HTML and get clean Markdown instantly. Supports headings, lists, links, code blocks, and tables.
Number to Korean Words
Convert numbers to Korean words (한글). Supports 만, 억, 조 units. Also shows Korean financial notation (일, 이, 삼...).
Number to Words Converter
Convert any number to English words instantly. Supports integers up to quintillions. Great for writing checks, legal documents, and accessibility.
Excel to CSV Converter
Convert Excel (.xlsx) files to CSV format online. Upload your spreadsheet and download the CSV instantly.
Length Converter
Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles instantly.
Currency Converter
Convert currencies with real-time exchange rates from Frankfurter API. USD, EUR, KRW, JPY and more. Free online currency converter.
JSON to Excel Converter
Convert a JSON array of objects to an Excel file, or an Excel file back to JSON, instantly. Free online JSON Excel converter.
CSV to Excel Converter
Convert CSV data to Excel (.xlsx) format online. Paste your CSV and download the spreadsheet file instantly.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly. Free online number base converter.
Weight Converter
Convert between milligrams, grams, kilograms, metric tons, ounces, and pounds instantly.
Data Storage Converter
Convert data storage sizes between B, KB, MB, GB, TB, and PB instantly. Free online data storage unit converter.
Roman Numeral Converter
Convert numbers to Roman numerals or Roman numerals to numbers instantly. Free online Roman numeral converter.
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin instantly. Enter any temperature and get the equivalent in all units.
Area Converter
Convert area between square meters, square feet, acres, hectares, and the Korean pyeong unit instantly. Free online area converter.
Volume Converter
Convert volume between milliliters, liters, cups, gallons, tablespoons, and more instantly. Free online volume converter.
Speed Converter
Convert speed between kilometers per hour, miles per hour, meters per second, and knots instantly. Free online speed converter.
Time Unit Converter
Convert between milliseconds, seconds, minutes, hours, days, weeks, months, and years instantly. Free online time converter.
Energy Converter
Convert between Joules, kilojoules, calories, kilocalories, watt-hours, kWh, BTU, and electron-volts. Free energy converter.
Pressure Converter
Convert between Pascal, hPa, kPa, MPa, bar, mbar, atm, psi, mmHg, and inHg. Free online pressure converter.
Angle Converter
Convert angles between degrees, radians, gradians, turns, arcminutes, and arcseconds. Free online angle converter.
Fuel Efficiency Converter
Convert fuel efficiency between L/100km, km/L, US mpg, and UK mpg. Free online fuel consumption converter.
Cooking Measurement Converter
Convert cooking measurements between teaspoons, tablespoons, cups, fluid ounces, pints, quarts, liters, and milliliters.
Clothing Size Converter
Convert clothing sizes between Korean (KR), US, EU, UK, and Japanese standards. Men's tops, women's tops, pants, and shoes.
Network Tools
12Subnet Calculator
Calculate subnet mask, network address, broadcast address, first/last host, and total hosts from CIDR notation. Supports IPv4 subnetting.
User-Agent Parser
Parse any User-Agent string to identify browser, OS, device type, and rendering engine. Auto-detects your current browser.
My IP Address
Find out your public IP address instantly. Shows your IPv4 or IPv6 address as seen by websites and servers you connect to.
URL Parser & Analyzer
Parse any URL into its components: scheme, host, port, path, query parameters, and fragment. Free online URL parser.
IPv4 Subnet Calculator
Calculate IPv4 subnet details: network address, broadcast, subnet mask, usable hosts, and more. Enter CIDR notation.
DNS Lookup
Look up DNS records (A, AAAA, MX, NS, TXT, CNAME) for any domain instantly using Google's public DNS resolver.
HTTP Status Codes
Browse all HTTP status codes with descriptions. Filter by 1xx, 2xx, 3xx, 4xx, and 5xx categories. Quick reference for web developers.
WHOIS Lookup
Look up domain registration details including registrar, creation date, expiry date, name servers, and registrant info via WHOIS protocol.
HTTP Headers Checker
Inspect HTTP response headers for any URL. See status code, all response headers, and identify missing security headers like HSTS, CSP, and X-Frame-Options.
SSL Certificate Checker
Check the SSL/TLS certificate for any domain. View expiry date, days remaining, issuer, cipher suite, TLS version, and Subject Alternative Names.
IP Geolocation Lookup
Find the geographic location of any IP address or domain — country, city, region, ISP, coordinates, and timezone.
IP Subnet Visualizer
Visualize any IPv4 or IPv6 subnet with CIDR notation. View network address, broadcast, usable host range, binary representation, and auto-generated subnets.
Image Tools
21Image Color Palette Extractor
Extract dominant colors from any image to create a color palette. Get HEX, RGB, and HSL values for the most prominent colors in your photo or design.
Image Color Picker
Pick any color from an uploaded image. Click on the image to get HEX, RGB, and HSL color values instantly.
Image Cropper
Crop images online for free. Select a crop area with fixed or free aspect ratio. Supports JPEG, PNG, and WebP. Download cropped image instantly.
Image EXIF Viewer
View EXIF metadata from JPEG photos including camera model, aperture, shutter speed, ISO, GPS location, and more. No upload needed — processed in browser.
Image Grayscale Converter
Convert any image to grayscale online. Upload your photo and download a black-and-white version instantly.
Image Text Overlay
Add text to images online. Set font, size, color, and position. Download the result as PNG.
SVG to PNG Converter
Convert SVG files to PNG images online. Set custom width, height, and background color. Download high-resolution PNG instantly.
Image Compressor
Compress JPEG and PNG images online without losing quality. Reduce file size instantly in your browser.
Image Resizer
Resize any JPEG, PNG, or WebP image by width and height. Maintain aspect ratio or stretch to exact dimensions.
Random Color Generator
Generate random color palettes with HEX, RGB, and HSL values. Get up to 20 random colors at once. Free color palette generator.
Image Converter
Convert images between PNG, JPEG, and WebP formats instantly. Upload any supported image and download it in your target format.
Image Filter
Apply image filters online: grayscale, sepia, negative, blur, and sharpen. Upload any image and download the filtered result instantly.
Image Dimensions Checker
Check image dimensions, aspect ratio, file size, and megapixels instantly. No upload required — works entirely in your browser.
Favicon Generator
Generate a complete favicon package from any image: favicon.ico plus PNG sizes for web, iOS, and Android. Free online favicon generator.
EXIF Remover
Remove EXIF metadata, including GPS location, from photos instantly. Free online EXIF remover.
Image Watermark
Add a text watermark to an image with adjustable position and opacity. Free online image watermark tool.
Image Flip & Rotate
Flip images horizontally or vertically, or rotate 90°, 180°, 270°. Free online image flip and rotate tool.
Image Metadata Editor
View and edit EXIF metadata in JPEG and WebP images. Edit artist, copyright, description, camera info, and optionally remove GPS location data for privacy.
Color Palette Generator
Extract dominant colors from any image and get a beautiful color palette with hex, RGB, and HSL values.
Image to Base64 Converter
Convert any image (JPEG, PNG, GIF, WebP) to a Base64-encoded Data URL. Copy and use directly in HTML or CSS.
Image Border Adder
Add a colored border of any size to your images online. Choose border thickness and color. Free image border generator.
Electrical Tools
14Capacitor Calculator
Calculate capacitor size for power factor correction (μF) or capacitor energy (J). Supports kW, kVA input with target power factor.
Motor Current Calculator
Calculate rated current and starting current for AC motors. Supports single-phase and three-phase motors with efficiency and power factor.
Solar Panel Calculator
Calculate solar panel energy output, system size, and estimated electricity bill savings. Enter panel wattage, quantity, peak sun hours, and efficiency.
Three-Phase Power Calculator
Calculate three-phase active power (kW), apparent power (kVA), and reactive power (kVAR). Also find current from power.
Transformer Calculator
Calculate transformer turns ratio, secondary voltage, secondary current, and kVA rating. Supports step-up and step-down transformers.
Korean Electricity Bill Calculator
Calculate your monthly Korean electricity bill based on 2024 residential progressive rates. Includes base fee, energy fee, VAT, and electricity fund.
Wire Gauge Calculator
Calculate the correct wire cross-section (mm²) and AWG size based on current, distance, voltage, and allowed voltage drop. Supports copper and aluminum, single and three-phase.
Voltage Drop Calculator
Calculate voltage drop across a wire run. Shows voltage drop in volts and percentage. Checks compliance with KEC indoor (3%) and outdoor (5%) limits.
Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's law. Enter any two values to compute the other two instantly. Supports milli/kilo units.
LED Resistor Calculator
Calculate the correct series resistor for LED circuits. Enter supply voltage, LED forward voltage, and current to get resistor value, power rating, and nearest E12 standard value.
Resistor Color Code Decoder
Decode resistor color bands to get resistance value and tolerance. Supports 4-band and 5-band resistors with visual color band display.
Battery Runtime Calculator
Calculate how long a battery will last given its capacity and load current. Or find required battery capacity for a target runtime. Supports mAh, Ah, Wh units.
Appliance Energy Cost Calculator
Calculate monthly electricity cost for multiple home appliances. Enter wattage and daily usage hours to see kWh consumption and cost per device and in total.
Circuit Breaker Sizing Calculator
Calculate the correct circuit breaker size for your electrical load. Supports current or power input, single/three-phase, and adjustable safety factor. Based on IEC/KS standard breaker sizes.
PDF Tools
6PDF Merger
Merge 2 to 10 PDF files into a single document. Upload your PDFs and download the combined file instantly.
PDF Splitter
Extract specific pages from a PDF file. Enter a page range like 1-3, 5, 7-9 and download the extracted PDF instantly.
PDF to Image
Convert PDF pages to PNG or JPEG images online. Select any page range and download as individual files or a ZIP archive.
Image to PDF Converter
Convert JPG, PNG, and WebP images to a single PDF file online. Free, fast, and easy to use.
PDF Compressor
Compress a PDF by recompressing embedded images while preserving text and layout. Free online PDF compressor.
PDF Watermark
Add a text watermark like DRAFT or CONFIDENTIAL to every page of a PDF instantly. Free online PDF watermark tool.
Calculators
35BMR & TDEE Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) based on your height, weight, age, sex, and activity level.
Break-Even Calculator
Calculate break-even point in units and revenue. Enter fixed costs, variable cost per unit, and selling price to find when your business becomes profitable.
Credit Card Payoff Calculator
Calculate how long it takes to pay off credit card debt. Compare minimum payments vs fixed payments and see total interest paid.
Debt Payoff Calculator
Compare the debt avalanche (highest interest first) and debt snowball (smallest balance first) strategies. See payoff order, timeline, and total interest saved.
Inflation Calculator
Calculate the purchasing power of money over time using historical inflation rates. Find out how much a past amount is worth today, or project future values.
Pregnancy Due Date Calculator
Calculate your pregnancy due date from last menstrual period or conception date. See gestational age, trimester, and key milestones.
Retirement Calculator
Calculate how much you need to save for retirement. Enter current savings, monthly contribution, expected return, and retirement age to project your nest egg.
ROI & CAGR Calculator
Calculate return on investment (ROI) and compound annual growth rate (CAGR). Enter initial investment, final value, and time period.
Scientific Calculator
Scientific calculator with sin, cos, tan, log, square root and more. Supports degree and radian modes.
Sleep Cycle Calculator
Find the best bedtime or wake-up time based on 90-minute sleep cycles. Wake up refreshed, not groggy.
Tip & Bill Split Calculator
Calculate the tip amount and split the total bill evenly among friends. Adjust tip percentage and number of people to find each person's share.
Korean VAT Calculator
Calculate Korean VAT (10%) instantly. Enter any amount to get the supply price, VAT, and total — with or without tax included.
Percentage Calculator
Calculate percentages instantly. Find X% of Y, what percent X is of Y, or the percentage change between two values.
Korean Severance Pay Calculator
Calculate severance pay (퇴직금) under Korean labor law. Based on average daily wage and years of service.
Calorie Calculator (TDEE)
Calculate your daily calorie needs (TDEE) using the Mifflin-St Jeor equation. Get BMR and weight loss/gain targets based on your activity level.
GPA Calculator
Calculate your GPA on 4.0 or 4.5 scale. Enter course names, grades, and credits to compute weighted GPA instantly.
Mortgage Calculator
Calculate your monthly mortgage payment, total cost, and interest paid. Supports KRW and USD. Based on fixed-rate amortization formula.
Korean Social Insurance Calculator
Calculate Korean 4 major social insurance deductions: national pension, health insurance, employment insurance, and industrial accident insurance.
Korean Net Salary Calculator
Calculate take-home pay from annual salary in Korea. Accounts for income tax, national pension, health insurance, and employment insurance.
Statistics Calculator
Calculate mean, median, mode, standard deviation, variance, min, max, and more from a list of numbers. Free statistics calculator.
BMR & TDEE Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation.
Compound Interest Calculator
Calculate compound interest growth with annual, quarterly, monthly, or daily compounding. Free online compound interest calculator.
Loan Calculator
Calculate your monthly loan payment, total repayment, and total interest. Enter principal, interest rate, and term.
Fuel Cost Calculator
Calculate the total fuel cost for a trip based on distance, fuel efficiency (L/100km), and fuel price per liter.
Savings Calculator
Calculate the maturity amount of a fixed monthly installment savings plan. Free online savings calculator.
Aspect Ratio Calculator
Calculate the aspect ratio from width and height. Get the simplified ratio and common equivalent sizes instantly.
BMI Calculator
Calculate your Body Mass Index (BMI) and weight category instantly. Free online BMI calculator using Asian-specific WHO thresholds.
Korean Minimum Wage Calculator
Calculate hourly, daily, weekly, monthly, and annual wages based on Korea's 2025 minimum wage of 10,030 KRW per hour.
Discount Calculator
Calculate the discount amount and final price instantly. Free online discount calculator.
Unemployment Benefit Calculator (Korea)
Estimate Korean unemployment insurance benefits based on monthly wage, coverage period, and age. Based on 2025 employment insurance rules.
Korea Property Acquisition Tax Calculator
Calculate Korean property acquisition tax (취득세), rural development tax, and local education tax for home purchases.
Tip Calculator
Calculate tip amount and split the bill among any number of people. Free online tip calculator.
Korea Comprehensive Income Tax Calculator
Estimate Korean comprehensive income tax (종합소득세) and local income tax for freelancers and self-employed. Based on 2025 tax brackets.
Body Fat Calculator (Navy Method)
Calculate your body fat percentage using the U.S. Navy formula. Enter height, weight, neck, and waist measurements.
Unit Price Calculator
Calculate unit price from total amount and quantity, or find the total from unit price. Also calculate profit margin and markup.
Text Tools
24Emoji Picker
Browse and search over 1800 emojis by category or keyword. Click to copy any emoji to your clipboard instantly.
Text Diff Checker
Compare two text blocks and highlight differences line by line. Shows added, removed, and unchanged lines with color coding.
Text Sorter
Sort lines of text alphabetically, numerically, by length, or randomly. Options to reverse, deduplicate, and ignore case.
Text to Speech
Convert text to speech online for free. Choose from available voices, adjust speed and pitch, and listen directly in your browser using Web Speech API.
Time Calculator — Add & Subtract Time
Add or subtract hours, minutes, and seconds. Calculate total working hours or time differences across multiple entries.
URL Extractor
Extract all URLs and links from any block of text instantly. Remove duplicates, sort alphabetically, and copy results with one click.
Whitespace Cleaner
Remove or normalize whitespace in text. Trim edges, collapse multiple spaces, remove blank lines, and fix line endings.
Word Counter
Count words, characters, sentences, lines, and reading time for any text instantly.
Text Case Converter
Convert text to UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case, and more.
Text Line Tools
Sort, deduplicate, reverse, shuffle, and trim lines of text online. Free and instant.
Markdown to HTML Converter
Convert Markdown to HTML instantly. Preview the output and copy the HTML source. Free online Markdown renderer.
Slug Generator
Convert any text into a clean, URL-friendly slug instantly. Free online slug generator.
Caesar Cipher / ROT13
Encrypt or decrypt text using the Caesar cipher with any shift, including the classic ROT13. Free online Caesar cipher tool.
Word Frequency Analyzer
Analyze word frequency in any text. Find the most common words, total word count, and unique word count instantly.
Morse Code Converter
Translate text to Morse code or decode Morse code back to text instantly. Free online Morse code converter.
Palindrome Checker
Check if a word, phrase, or sentence is a palindrome. Ignore case and spaces for flexible palindrome detection.
Number Formatter
Format any number as standard, Korean won, USD, EUR, scientific notation, percentage, or Korean units (만/억/조). Copy formatted values instantly.
Text Truncator
Truncate text by character count, word count, or line count. Optionally add an ellipsis. Free online text truncation tool.
Text Deduplicator & Line Sorter
Remove duplicate lines, sort lines alphabetically, remove empty lines, or shuffle. Free online text deduplicator and line sorter.
Reading Time Estimator
Estimate how long it takes to read any text. Shows word count, character count, and reading time for slow, average, and fast readers.
Text Reverser
Reverse text character by character, reverse word order, reverse line order, or reverse each line individually. Free online text reverser.
Find & Replace
Find and replace text with support for case-sensitive matching and regular expressions. Free online find and replace tool.
Line Number Tool
Add line numbers to text with custom start number and separator, or remove existing line numbers. Free online line numbering tool.
Vigenère Cipher Encoder / Decoder
Encode and decode text with the Vigenère cipher using a custom keyword. Classic polyalphabetic substitution cipher.
Date Tools
10Countdown Timer
Count down to any date or event. Live countdown showing days, hours, minutes and seconds. Set a target date and share the link.
Meeting Time Zone Planner
Find the best meeting time across multiple time zones. Visualize overlapping business hours for international teams. Add cities and see availability at a glance.
Week Number Calculator
Find the ISO week number for any date. See what week of the year a date falls in and which dates belong to a given week number.
D-Day Calculator
Calculate how many days until (or since) any date. Perfect for countdowns to weddings, exams, vacations, and more.
Date Difference Calculator
Calculate the number of days, weeks, and years/months/days between two dates instantly. Free online date difference calculator.
Age Calculator
Calculate your international age (Western) and Korean age from your date of birth. Shows days until your next birthday.
Business Day Calculator
Add business days to a date, or count business days between two dates, excluding weekends. Free online business day calculator.
World Clock Converter
Convert a date and time to multiple time zones around the world instantly. Free online world clock converter.
Korean Lunar-Solar Calendar Converter
Convert dates between the Korean lunar calendar and the solar (Gregorian) calendar instantly, including leap months and the sexagenary Gapja cycle. Free online tool.
Korean Public Holiday Checker
Check all Korean statutory public holidays for any year, including lunar-based holidays like Seollal and Chuseok. Free online tool.