All Tools

Explore the full list of free online web tools on BlingCubby: calculators, date/time tools, text utilities, converters, image tools, developer tools, random pickers, and life tools. Tool pages include usage situations, examples, cautions, FAQs, and related tools.

Tools List by Category

Percentage Calculator - Find what percentage a part is of a whole, or calculate a percentage of a value.
Discount Calculator - Enter the original price and discount rate to find the final price and the amount saved.
Ratio Calculator - Simplify the ratio of two values, or solve for the unknown in a proportion.
Pyeong Area Converter - Convert apartment and office area between pyeong, square meters (m²), and square feet (ft²).
Unit Converter - Freely convert units of length (nanometer to mile), weight, temperature, area, and volume.
VAT Calculator - Calculate 10% VAT from either the supply price or the total amount.
Average Calculator - Calculate the average, maximum, minimum, and sum of a list of numbers.
Percentage Change Calculator - Enter a previous and current value to calculate the rate of increase or decrease.
Goal Achievement Calculator - Enter a target and current value to see the achievement rate (%) and the amount remaining.
Rounding Calculator - Round, round up, or round down a number to a chosen number of digits.
Split the Bill Calculator - Enter a total amount and the number of people to calculate the amount per person.
Margin & Cost Calculator - Calculate the margin from cost and selling price, or find the price from a target margin.
Reverse Percentage Calculator - Work back to the original value from a result and its percentage.
Price Increase/Decrease Calculator - Enter the current price and a change rate (%) to find the new price and the amount changed.
Break-Even Point Calculator - Calculate the break-even quantity from fixed costs, variable costs, and selling price.
Fee Calculator - Calculate the net amount after payment and platform fees.
Exchange Rate Memo Calculator - Enter an exchange rate yourself to convert between local and foreign currency.
Hourly Wage Calculator - Calculate the hourly wage from monthly salary, workdays, and work hours.
CAGR Calculator - Calculate the compound annual growth rate from start value, end value, and period.
ROI Calculator - Enter investment and return amounts to calculate profit, ROI, and the return multiple at once.
PPI Calculator - Calculate pixel density (PPI) and dot pitch from screen diagonal size and resolution.
Date Difference Calculator - Calculate the number of days between two dates, or the date N days from a reference date.
D-Day Calculator - Show the days remaining until, or elapsed since, a target date based on today.
Age Calculator - Calculate your exact age, this year's birthday status, and days until your next birthday.
Time Calculator - Add or subtract time from a clock time, and calculate the interval between two times.
Timestamp Converter - Convert Unix timestamps to readable dates and dates back to Unix timestamps.
Months Between Dates Calculator - Calculate total months, days, and a year/month/day breakdown between two dates.
Day of the Week Calculator - Find the day of the week for a date and its day difference from today.
Leap Year Checker - Check whether a year is a leap year and how many days February has that year.
Stopwatch - Measure time in milliseconds and record lap times.
Countdown Timer - A countdown timer that alerts you when the set time reaches zero.
Pomodoro Timer - A timer with 25-minute focus and 5-minute break cycles to boost concentration.
Character Counter - Count characters with and without spaces, and line count, in real time.
Byte Counter - Calculate the byte length of text when stored as UTF-8.
Case Converter - Convert text, variable names, and filenames to UPPER, camelCase, snake_case, kebab-case, and more.
Whitespace Remover - Remove whitespace in various ways — leading/trailing, duplicate, or per-line.
Duplicate Line Remover - Remove duplicate lines from text, keeping only unique lines.
Line Sorter - Sort each line of text in ascending/descending order, or shuffle randomly.
Markdown Preview - Render Markdown in real time and provide an HTML preview.
Random String Generator - Generate a random string with a chosen length and character set.
Word Counter - Calculate word count, unique word count, and sentence count of text.
Line Counter - Count total lines, empty lines, content lines, and the longest line length.
Text Compare - Compare two texts line by line to show added, removed, and identical lines.
Slug Generator - Convert a title or sentence into a URL-friendly slug string.
List Converter - Convert between a comma-separated list and a line-based list.
Line Number Add/Remove - Add numbers to each line of text, or remove existing line numbers.
Text Reverser - Reverse text character by character, or reverse the order of lines.
Random Order Shuffler - Shuffle the line order of a list randomly for draws, ordering, and random sorting.
Quote Converter - Convert between straight quotes and smart (curly) quotes.
Bracket Remover - Remove various brackets — parentheses, square, and curly — from text.
Punctuation & Whitespace Cleaner - Tidy punctuation and whitespace — duplicate spaces, consecutive blank lines, and per-line edges.
Lorem Ipsum Generator - Generate Lorem Ipsum placeholder text for design mockups and development testing.
Text Template Filler - Replace {variable} placeholders with your values in bulk.
Text Extractor - Automatically find and extract emails, URLs, phone numbers, and numbers from text.
Markdown Table Generator - Set columns and rows and enter content to generate Markdown table syntax instantly.
Special Character Table - Copy common special characters — math, arrows, currency, punctuation — with one click.
Emoji Picker - Click category-organized emoji — smileys, animals, food, travel — to copy instantly.
Korean/English Typo Converter - Fix Korean text mistyped on an English keyboard layout, or vice versa.
ASCII Art Generator - Convert text into ASCII art made of block characters.
Markdown Table of Contents Generator - Analyze Markdown headings (#, ##, ###) to auto-generate a linked table of contents.
Markdown Anchor Link Generator - Convert heading text into a GitHub-style anchor link.
Checklist Converter - Convert a plain line list into a Markdown checklist (- [ ] item) format.
Prefix/Suffix Adder - Add a prefix (front) and suffix (back) string to each line in bulk.
Line Filter - Filter lines of text by keyword include/exclude conditions.
Random Line Picker - Randomly pick a specified number of lines from multi-line text.
Text Masking Tool - Mask parts of personal data such as emails, phone numbers, and names with *.
Korean Particle (Josa) Helper - Analyze the final consonant of a word to auto-select the right Korean particle (eun/neun, i/ga, eul/reul, gwa/wa).
Korean Initial Consonant Extractor - Extract the leading consonant of each character from Korean text.
Hangul Jamo Splitter/Combiner - Split Hangul into initial/medial/final jamo, or recombine separated jamo into complete Hangul.
Forbidden Word Checker - Find and highlight forbidden words in text based on a user-provided list.
Text Highlighter - Highlight multiple keywords in text and see found keywords and match counts in real time.
Invisible Character Detector - Find, show, and clean invisible characters like zero-width spaces, full-width spaces, and BOM.
URL Encode / Decode - Encode text into URL-safe form (%XX) or decode an encoded URL back to text.
Base64 Converter - Encode text to Base64 or decode a Base64 string back to text.
Image Resizer - Resize multiple images in the browser with aspect ratio kept, no server upload.
Image Cropper - Enter pixel coordinates to crop just the area you need, in the browser.
Image Rotate / Flip - Rotate images in 90-degree steps or flip them horizontally/vertically.
Image Compressor - Reduce image file size in the browser by adjusting quality and max size.
Image Format Converter - Convert PNG, JPG, and WebP images to each other in the browser.
Favicon Generator - Generate multiple favicon and app-icon PNG sizes from a source image.
Image Color Extractor - Analyze image pixels in the browser to extract the main color HEX codes.
Image to Base64 Converter - Convert an image file into a Data URL Base64 string, no server upload.
Base64 → Image Preview - Instantly preview a Data URL Base64 string as an image.
Image Metadata Remover - Make a new image with original metadata like EXIF removed via Canvas re-encoding.
Image Watermark - Add a text or logo watermark over an image with adjustable position and opacity.
Image Mosaic / Blur - Blur sensitive areas like faces, names, and addresses in photos/screenshots, in the browser.
Image Rounded Corners - Generate a transparent-background PNG with rounded image corners.
Add Image Padding - Add padding of a chosen color around an image.
Image Grid Maker - Combine multiple images into one PNG in a grid layout.
Before/After Image Maker - Combine two images into a side-by-side or stacked comparison image.
OG Image Generator - Generate a 1200×630 share image from a title, subtitle, and colors.
Thumbnail Generator - Make a simple 1280×720 thumbnail image from text and a background color.
Image Pixelate Tool - Process an image in blocks for a pixel-art look and save as PNG.
Image Tint Tool - Apply a color overlay or tint to an image.
Solid Color Image Generator - Generate a solid-color PNG image from a color and size.
Gradient Image Generator - Generate a gradient PNG image from two colors and a direction.
SVG Preview - Render SVG code as an image in the browser to preview it.
SVG Minifier - Clean up comments and unnecessary whitespace in an SVG string.
SVG Color Replacer - Bulk-replace fill/stroke color values in SVG code with a chosen color.
SVG Background Pattern Generator - Generate repeating background patterns (dots, stripes, grid) as SVG code for web backgrounds.
SVG → PNG Converter - Render SVG code on Canvas and save it as a PNG image.
HTML Escape / Unescape - Convert HTML special characters to entities, and restore entity strings back to characters.
Color Code Converter - Convert HEX, RGB, RGBA, HSL, HSLA color codes to each other and preview the color.
File Size Converter - Convert Byte, KB, MB, GB, TB file size units on a 1000 or 1024 basis.
YAML ↔ JSON Converter - Convert YAML and JSON data bidirectionally in the browser.
Markdown → HTML Converter - Convert a Markdown document to HTML with a rendered preview.
CSV ↔ JSON Converter - Convert CSV and JSON array data bidirectionally.
CSV ↔ Markdown Table Converter - Convert CSV data into a Markdown table, or a Markdown table back into CSV.
Image to PDF Converter - Convert JPG/PNG/WebP images into a PDF.
PDF to Image Converter - Convert PDF pages into PNG/JPG images.
PDF Merge - Combine multiple PDF files into one document in the selected order.
PDF Split - Split a PDF by page into individual files for each page.
PDF Page Extractor - Select only the pages you want and save them as a new PDF.
PDF Page Remover - Make a new PDF from the remaining pages after excluding selected ones.
PDF Page Rotator - Rotate wrongly oriented PDF pages by 90, 180, or 270 degrees.
TSV ↔ CSV Converter - Convert tab-separated data (TSV) and comma-separated CSV to each other.
JSON Flatten Converter - Flatten nested JSON into a flat key-value structure.
JSON Schema Generator - Generate a JSON Schema draft from a JSON sample.
TOML ↔ JSON Converter - Convert TOML config and JSON data bidirectionally in the browser.
INI ↔ JSON Converter - Convert INI config files and JSON data to each other.
Excel Paste → Markdown - Convert table-form text into a Markdown table.
Markdown Table → HTML - Convert a Markdown table into an HTML table.
CSS Unit Converter - Convert px, rem, em, %, vw, and vh.
Query String ↔ JSON Converter - Convert URL query strings and JSON objects bidirectionally.
JSON ↔ TypeScript Type Converter - Convert between JSON samples and TypeScript type declarations to draft types and sample JSON.
HTML → JSX Converter - Convert HTML markup into the attribute names and style format used in React JSX.
px ↔ rem Converter - Convert px and rem values bidirectionally based on a root font size.
Date Format Converter - Convert date and time into YYYY-MM-DD, ISO 8601, UTC, and Unix timestamp formats.
Unicode Converter - Convert a character to its Unicode code point (U+XXXX), or a code point to a character.
ASCII Code Converter - Convert between characters and ASCII codes (decimal/hex/binary).
Number Base Converter - Convert between binary, octal, decimal, and hexadecimal.
Roman Numeral Converter - Convert between Arabic numbers and Roman numerals (I, V, X, L, C, D, M).
Hash Generator - Convert text into SHA-1, SHA-256, SHA-384, and SHA-512 hashes.
Caesar Cipher - Encrypt and decrypt text with a Caesar cipher that shifts letters by a set amount.
HTML → Text Extractor - Remove HTML tags and cleanly extract only the body text.
HTML → Markdown Converter - Convert HTML markup to Markdown syntax — headings, lists, tables, and code blocks.
CSV → SQL INSERT Generator - Convert CSV data into SQL INSERT statements ready to load into a table.
XML ↔ JSON Converter - Convert XML and JSON data bidirectionally, preserving attributes and text.
Markdown → Plain Text Converter - Remove Markdown syntax symbols and leave only pure plain text.
SVG Data URI Converter - Convert SVG code into a Data URI usable directly in CSS and HTML.
Code to Image Generator - Turn a code snippet into a PNG image for sharing on social media and documents.
Image Aspect Ratio Calculator - Calculate the ratio from image width/height and find a ratio-preserving size.
JSON Formatter - Beautify or minify JSON strings instantly and check for validity errors.
UUID Generator - Generate up to 20 cryptographically secure UUID v4 values at once.
Password Generator - Generate secure random passwords in the browser by choosing length, character set, and count.
JWT Decoder - Decode a JWT header and payload to view the JSON and key claims.
Regex Tester - Enter a regex pattern to see matches in text in real time.
QR Code Generator - Convert text or a URL into a QR code and download it as an image.
Wi-Fi QR Code - Make a QR code from Wi-Fi network info so guests can connect easily.
UTM Parameter Builder - Add UTM parameters to a URL to build a marketing campaign tracking link.
CSS vw Unit Converter - Convert px to viewport-width vw units, or the reverse.
CSS clamp() Generator - Auto-generate a CSS clamp() function from min/max values and a viewport range.
Color Palette Picker - Pick a color and view its HEX, RGB, HSL values plus complementary and analogous colors.
SQL Formatter - Neatly align SQL queries by keywords and clauses.
HTML Formatter - Tidy HTML markup with consistent indentation and line breaks.
CSS Formatter - Neatly align CSS code by rules and properties.
JavaScript Formatter - Tidy JavaScript code for readability using Prettier rules.
JS/CSS Minifier - Minify JavaScript and CSS code by removing whitespace and applying minify rules.
XML Formatter - Parse an XML document and indent it by hierarchy.
YAML Formatter - Tidy a YAML document with consistent indentation and line breaks.
Code Diff Tool - Compare two code or text inputs line by line to show additions and deletions.
Cron Expression Generator - Generate a cron expression by combining minute, hour, day, month, and weekday values.
Cron Next Run Calculator - Calculate the next run times of a cron expression based on the current time.
HTTP Status Code Lookup - Quickly look up the name and meaning of an HTTP status code.
MIME Type Lookup - Quickly find file extensions and MIME types.
Keyboard Event Inspector - Instantly check the key, code, and modifier values of a key press event.
User-Agent Analyzer - Extract browser, OS, and device info from a User-Agent string.
Regex Replace Tester - Apply a regex pattern and replacement value to see the result.
JSONPath Tester - Extract values from JSON data using a JSONPath expression.
CSS box-shadow Generator - Adjust shadow values with sliders and generate box-shadow CSS.
CSS border-radius Generator - Check rounded-corner values with a preview and generate border-radius CSS.
CSS gradient Generator - Adjust colors and angle to generate linear-gradient CSS.
CSS easing Generator - Adjust cubic-bezier values to generate a CSS easing function.
Flexbox Generator - Adjust flex-direction, justify-content, align-items, and gap to generate Flexbox CSS.
Grid Generator - Adjust columns, gap, and item count to generate CSS Grid layout code.
z-index Organizer - Enter names and z-index values per line and sort from lowest to highest.
cURL → fetch Converter - Convert a cURL command into JavaScript fetch code.
fetch → axios Converter - Convert fetch code into the axios request format.
HTTP Header Parser - Parse a header string into key-value form.
.env Sorter - Sort keys in a .env file and find duplicate keys.
package.json Viewer - Neatly organize scripts, dependencies, and devDependencies.
semver Comparator - Compare two semantic versions and interpret version range notation.
Gitignore Generator - Generate gitignore templates by language/framework.
Dockerfile Formatter - Tidy Dockerfile commands and present the structure clearly.
Docker Compose Formatter - Neatly tidy docker-compose YAML.
URL Parser - Break a URL into protocol, host, path, and query.
User-Agent Generator - Generate User-Agent strings for testing.
API Latency Summary - Calculate the mean, p95, and p99 of a list of response times.
GraphQL Formatter - Tidy GraphQL queries and mutations.
GraphQL Variable Merger - Merge a GraphQL query and variables JSON into an API request body.
SQL IN Clause Generator - Convert a line list into a SQL IN (…) form.
JSON Mock Data Generator - Generate a sample JSON array based on field definitions.
CSS text-shadow Generator - Adjust X/Y offset, blur, color, and opacity to make CSS text-shadow code.
CSS filter Generator - Generate CSS filter values like blur, brightness, contrast, and grayscale with a preview.
Color Shades Palette Generator - Generate a 50–950 Tailwind-style shade palette from one base HEX color.
Meta / OG Tag Generator - Generate title, description, canonical, OG, and Twitter Card meta tag HTML.
JSON → Table Converter - Convert a JSON object array into a rows-and-columns table and export to CSV.
JSON Tree Viewer - Show JSON data as a collapsible/expandable tree structure.
CSS Specificity Calculator - Calculate and compare the specificity score of CSS selectors.
Git Branch Name Generator - Convert a task title into a name following Git branch naming conventions.
Ladder Game - Enter participants and result items to connect them randomly.
Spin Wheel Picker - Pick one item randomly from a candidate list like a spinning wheel.
Dice Roller - Set the number of sides and dice to generate random results and a total.
Coin Flip - Generate heads/tails results once or several times.
Random Name Picker - Randomly draw names from a participant list without duplicates.
Random Team Generator - Shuffle a participant list and split by team count or members per team.
Random Menu Picker - Randomly recommend what to eat today from a menu candidate list.
Random Color Generator - Randomly generate HEX and RGB color codes with a preview.
Random Date Generator - Generate random dates within a start and end date range.
Passphrase Generator - Generate an easy-to-remember passphrase by combining words.
Random ID Generator - Create unique ID strings by choosing a prefix, length, and character type.
Random Nickname Generator - Generate Korean-style nicknames by combining adjectives and animal nouns.
Random Sentence Generator - Generate random Korean sentences by type, such as daily chat, business, or greetings.
Random Coordinate Generator - Generate random latitude and longitude values from presets or a custom range.
Random Date List Generator - Generate multiple random dates within a date range, with duplicate and sorting options.
Random Color Palette Generator - Generate harmonious color palettes using color-theory rules.
Number Wheel Picker - Set a number range and draw one number with a roulette-style animation.
Random Order Generator - Shuffle a participant list to decide presentation order, duty order, or turn order.
Lotto Number Generator - Generate six random numbers from 1 to 45 plus a bonus number.
Random Number Picker - Draw random numbers from a range with count and duplicate options.
Fuel Cost Calculator - Estimate fuel cost from driving distance, fuel economy, and fuel price.
Electricity Bill Calculator - Estimate a monthly electricity bill from power consumption in kWh.
Battery Runtime Calculator - Estimate runtime from battery capacity in mAh and device current draw.
Tip Calculator - Calculate tip amount, total payment, and per-person split from a bill and tip rate.
Book Spine Thickness Calculator - Calculate printed book spine thickness from page count and paper thickness.
Box Volume Calculator - Calculate box volume, surface area, and shipping dimensional weight from width, depth, and height.
Pet Age Calculator - Convert dog or cat age into an approximate human-age equivalent.
BMI Calculator - Calculate body mass index and a normal-weight range from height and weight.
BMR Calculator - Estimate daily basal metabolic rate from sex, age, height, and weight.
Calorie Calculator - Estimate maintenance, weight-loss, and weight-gain calories from BMR and activity level.
Water Intake Calculator - Estimate daily water intake from body weight and a per-kg hydration rule.
Caffeine Intake Calculator - Add up caffeine from drinks and compare daily intake against common guidance limits.
Walking Calorie Calculator - Estimate calories burned from walking based on weight, distance, and pace.
Running Pace Calculator - Calculate pace from distance and time, or estimate finish time from pace.
Moving Box Calculator - Estimate how many moving boxes you need from home size, room count, and packing density.
Food Storage Memo - Record food items, storage places, and dates to estimate expiration or use-by reminders.
Tire Pressure Converter - Convert tire pressure between psi, bar, and kPa and compare common vehicle presets.
Screen Size Compare - Compare display sizes by diagonal, aspect ratio, width, height, and screen area.
Travel Budget Splitter - Split travel expenses by people and categories to estimate each person's share.
Checklist Generator - Create a practical checklist from a topic or item list for trips, moving, shopping, or tasks.
Annual Leave Calculator - Estimate accrued annual leave days from a hire date and a reference date (simplified).
Severance Pay Calculator - Estimate severance pay from the last three months of wages and length of service (simplified).
Net Salary Calculator - Estimate net take-home pay from gross salary, non-taxable amount, deduction rate, and income tax.
Pregnancy Week Calculator - Calculate the pregnancy week and due date from the last menstrual period (LMP).
Ovulation Calculator - Estimate ovulation day and the fertile window from the last period and average cycle.
World Clock Converter - Convert a given date and time to the local time of major cities and time zones at once.
Time Zone Converter - Convert a chosen date and time to another time zone's representation.
Business Day Calculator - Calculate a date N business days out or the number of business days, excluding weekends.
Week Number Calculator - Find which week of the year a date falls in, based on ISO 8601.
Date Range Generator - Generate a list of all dates between a start and end date at once.
Meeting Time Finder - Find times where working hours overlap across multiple time zones.
Date Add/Subtract Calculator - Add or subtract days, weeks, months, or years from a reference date.
Work Hours Calculator - Calculate work hours from clock-in, clock-out, and break time.
Sleep Time Calculator - Calculate recommended bedtimes aligned to 90-minute sleep cycles based on your wake time.
Unix Millisecond Converter - Auto-detect 10-digit second and 13-digit millisecond timestamps and convert to date/time.
Percentage Point Calculator - Calculate the difference between two percentage values as percentage points and relative change.
Compound Interest Calculator - Calculate compound results from initial amount, monthly contribution, rate, and period.
Loan Interest Calculator - Calculate monthly payment and total interest from loan principal, rate, term, and repayment method.
Deposit Interest Calculator - Calculate the maturity amount from deposit, rate, term, and interest tax.
Savings Interest Calculator - Calculate the maturity amount of a regular savings plan from monthly deposit, rate, term, and tax.
Average Cost Calculator - Calculate a new average purchase price from existing holdings and an additional buy.
Shoe Size Converter - Compare shoe sizes across Korea, US, UK, EU, Japan, and foot length.
Ring Size Converter - Convert ring size between Korean, US, UK, EU, circumference, and diameter values.
Clothing Size Converter - Compare clothing sizes across global, Korean, US, EU, and measurement-based standards.
Cooking Unit Converter - Convert common cooking units such as cups, tablespoons, teaspoons, mL, and grams.
Recipe Scaler - Scale recipe ingredient amounts by changing servings or applying a multiplier.
Baking Pan Converter - Compare baking pan sizes and calculate batter scaling by pan area.
Paint Calculator - Estimate paint amount from wall area, coverage, and number of coats.
Tile Calculator - Estimate tile count and material cost from area, tile size, and waste rate.
Wallpaper Calculator - Estimate wallpaper rolls from wall dimensions, roll size, and waste.
Curtain Size Calculator - Estimate curtain width and length from window size, fullness, and hanging style.
TV Viewing Distance Calculator - Estimate comfortable viewing distance from TV size and resolution.
Furniture Fit Calculator - Check whether furniture can fit through doors, elevators, hallways, or room spaces.
Alarm Clock - A simple alarm clock that runs in your browser and plays a synthesized beep.
Leap Month Calculator - Check whether a lunar month is normal or leap, and find leap-month date ranges by year.
Korean Zodiac Calculator - From a birth date, find the Korean zodiac sign by both Lunar New Year and Ipchun (solar term).
Samjae Calculator - Determine Samjae (the three-year unlucky cycle) status from a zodiac sign and reference year.
Zodiac Sign (Horoscope) Calculator - Find your Western zodiac sign from your solar birth date, with a personality summary.
Korean Milestone Birthday Calculator - Calculate Korean traditional longevity celebration dates and D-days (Hwangap 60th, Chilsun 70th, etc.).
49-Day Memorial Calculator - Calculate Buddhist memorial dates from the first rite to the 49th-day rite, with weekdays and D-days.
Sexagenary Cycle Calculator - Identify the sexagenary year, its symbolic animal and color, and trace years for a given cycle name.
Hash Generator - Hash text with MD5, SHA-1, SHA-256, and SHA-512. Supports HEX and Base64 output.
JSON Schema Validator - Validate JSON data against a JSON Schema (Draft-7) and show error locations as JSON Pointers.
Barcode Generator - Generate Code 128 and EAN-13 barcodes in your browser and download them as PNG images.
Chart Generator - Turn label/value data into bar, line, pie or doughnut charts and download them as SVG or PNG.
Browser Info - See the browser, OS, device, screen and locale details your browser reports — all locally.
RSA Calculator - Derive an RSA key (n, φ, d) from two primes and a public exponent, and walk through encryption/decryption. For learning only.
API Key Generator - Generate cryptographically secure random API keys in Base62, Hex, Base64URL or UUID formats, entirely in your browser.
XML Validator - Check whether XML is well-formed, view error messages, and get a tidy indented version.
YAML Validator - Validate YAML syntax, show error line/column positions, and preview the parsed JSON.
Subtitle Converter - Convert subtitles between SRT, WebVTT, SMI (SAMI) and plain text, with optional time shifting.
IEEE 754 Floating Point Converter - Break a decimal number into 32-bit and 64-bit IEEE 754, and decode hex/binary bit patterns back into numbers.
Flashlight - Turn your screen into a bright light source with color and brightness controls.
Online Metronome - Set BPM and hear precise beats with visual feedback using Web Audio API.
Spirit Level - Measure tilt using your device's orientation sensor to check horizontal and vertical alignment.
Decibel Meter - Measure ambient noise level (dB) in real time using your microphone.
Korean Family Relation Calculator - Select a family relationship to see the Korean kinship degree (촌수) and proper title.
Wire Gauge Converter - Convert between AWG and mm² wire gauges with diameter, resistance, and ampacity reference.
Resistor Color Band Calculator - Select color bands to calculate the resistance value (Ω) and tolerance.
Resistance to Color Band Calculator - Enter a resistance value to see the matching color band combination.
Swiss Round Calculator - Enter participants to auto-generate Swiss-system tournament pairings and manage standings.
ASCII Table - Browse all 128 ASCII characters with decimal, hex, octal, and descriptions. Search and click to copy.
Morse Code Converter - Convert text to Morse code and Morse code back to text using ITU standard.
Alphabet-Number Converter - Convert between alphabet letters and position numbers (A=1, B=2… Z=26) in both directions.
Manuscript Paper Converter - Visualize text on Korean 200/400-character manuscript paper grids and calculate page count.
Word Cloud Generator - Analyze word frequency from text and generate a visual word cloud with a frequency table.
Citation Generator - Auto-generate academic citations in APA 7th, MLA 9th, and Chicago formats.
Kana Name Converter - Convert Korean (Hangul) names to Japanese Katakana and Hiragana phonetic equivalents.
LCM Calculator - Calculate the least common multiple of two or more positive integers.
GCD Calculator - Calculate the greatest common divisor of two or more positive integers using the Euclidean algorithm.
Prime Number Checker - Check whether a natural number is prime and show its prime factorization when it is composite.
Polynomial Factorizer - Factor or solve a quadratic expression ax² + bx + c using the discriminant and quadratic formula.
Gaussian Elimination Calculator - Solve 2×2 to 5×5 systems of linear equations with Gaussian elimination.
Fraction ↔ Decimal Converter - Convert fractions to decimals and decimals to simplified fractions.
Modulo Calculator - Calculate a mod b and compare mathematical modulo with the JavaScript remainder operator.
Combinatorics Calculator - Calculate permutations, combinations, repeated permutations, and multiset combinations from n and r.
Fibonacci Calculator - Generate Fibonacci sequence values up to 100 terms and show the golden-ratio relationship.
Confidence Interval Calculator - Calculate Z- or t-based confidence intervals from sample mean, standard deviation, and sample size.
YouTube Thumbnail Extractor - Enter a YouTube URL or video ID to instantly extract and download thumbnail images in max, high, medium, and standard quality.
Color Contrast Checker - Calculate the WCAG 2.1 contrast ratio between a foreground and background color and check AA / AAA accessibility compliance.
Instagram Font Converter - Convert text into 11 Unicode font styles — bold, italic, script, gothic, double-struck, circled, and more — for Instagram bios and social media posts.
Online Notepad - A simple browser-based notepad that auto-saves your text locally. No login needed — just start typing.
Image to Text (OCR) - Extract text from images using in-browser OCR. Supports Korean, English, Japanese, and Chinese. No upload — all processing happens locally.