All Tools
Free calculators, converters, text tools, audio tools, electronics calculators, and image tools you can use without installation or sign-in. Each tool page includes instructions, examples, and FAQ.
Start with what you want to do
Text Tools
Count characters and words, remove spaces, and convert letter case.
Character Counter
Count characters, words, lines, and characters without spaces.
Remove Spaces
Remove extra spaces, leading and trailing spaces, or line breaks.
Case Converter
Convert English text to uppercase, lowercase, or title case.
Text Compare Tool
Compare two texts line by line and find added, removed, or changed lines.
Calculators
Calculate percentages, discounts, VAT, dates, BMI, margins, compound interest, and loan interest.
Percentage Calculator
Calculate percentages, ratios, increases, and decreases.
Discount Calculator
Enter the original price and discount rate to calculate the final price.
VAT Calculator
Calculate supply amount, VAT, and total amount.
Date Calculator
Calculate days between dates or dates before and after a base date.
D-Day Calculator
Check days remaining until a target date or days passed since it.
Age Calculator
Calculate age from birth date and base date.
BMI Calculator
Calculate BMI from height and weight.
Margin Calculator
Calculate margin amount and margin rate from cost and sale price.
Compound Interest Calculator
Calculate compound growth from principal, rate, and period.
Loan Interest Calculator
Calculate monthly payment and total interest from loan amount, rate, and term.
2026 Korea Salary Take-Home Pay Calculator
Estimate monthly take-home pay in Korea using 2026 National Pension, Health Insurance, Long-term Care, Employment Insurance, income tax, and local income tax rules.
Converters
Convert temperature, length, weight, pyeong, time, and time zone values into the format you need.
Unit Converter
Convert units across 12 categories: length, mass, temperature, area, volume, speed, time, data storage, pressure, energy, power, and angle.
Time Zone Converter
Convert time between major time zones and cities such as Korea, the United States, Japan, and the United Kingdom.
Unix Timestamp Converter
Convert Unix timestamps and date times.
Pyeong Calculator
Convert square meters and pyeong.
Audio Tools
Convert, trim, compress, and adjust audio files directly in your browser.
Audio Converter
Convert your own MP3, WAV, OGG, FLAC, M4A, and AAC audio files to MP3, WAV, OGG, or FLAC directly in your browser. Selected files are not uploaded to a server.
Audio Cutter
Trim your own MP3, WAV, OGG, and FLAC audio files directly in your browser and download the selected section. Selected files are not uploaded to a server.
Audio Compressor
Reduce MP3, WAV, OGG, and FLAC audio file size by adjusting bitrate and compression settings. Selected files are processed in your browser and are not uploaded to a server.
Audio Volume Editor
Adjust the volume of MP3, WAV, OGG, and FLAC audio files and add fade in or fade out effects directly in your browser. Selected files are not uploaded to a server.
iPhone Ringtone Maker
Select a section from an MP3, WAV, OGG, or FLAC waveform and convert it to an M4R ringtone for iPhone. Files are processed in your browser.
Audio Merger
Arrange, trim, and combine multiple MP3, WAV, OGG, and FLAC files into one audio file. Files are processed in your browser.
PDF Tools
Merge, split, extract, rotate, delete pages, add watermarks, add page numbers, and convert PDF files directly in your browser.
PDF Merger
Combine multiple PDF files into one PDF in your selected order. Selected files are processed in your browser and are not uploaded to a server.
PDF Splitter
Split a PDF file by page or page range and save the result as new PDF files. Selected files are not uploaded to a server.
PDF Page Extractor
Extract selected pages from a PDF file and save them as a new PDF. Selected files are processed in your browser and are not uploaded to a server.
Image to PDF
Convert JPG, PNG, and WebP images into a single PDF file in your selected order. Selected images are processed in your browser and are not uploaded to a server.
PDF Rotator
Rotate all or selected PDF pages by 90, 180, or 270 degrees and save them as a new PDF. Selected files are not uploaded to a server.
PDF Page Delete
Remove unwanted pages from a PDF file and save a new PDF. Selected files are processed in your browser and are not uploaded to a server.
PDF to JPG
Convert PDF pages to JPG images and download them. Selected PDF files are processed in your browser and are not uploaded to a server.
PDF Watermark
Add a text watermark to a PDF file and save it as a new PDF. Selected files are processed in your browser and are not uploaded to a server.
PDF Page Numbers
Add page numbers to a PDF file and save it as a new PDF. Selected files are processed in your browser and are not uploaded to a server.
PDF Organizer
Reorder, delete, and rotate PDF pages, then save the result as a new PDF. Selected files are not uploaded to a server.
Fun Tools
Fun online tools for image effects, random choices, lotto numbers, and simple games.
Lotto Number Generator
Generate six random lotto numbers from 1 to 45.
Image to ASCII Art
Convert JPG, PNG, and WebP images into monochrome or colored ASCII art. Customize characters and size, then export as TXT, PNG, or HTML.
Image to Pixel Art
Convert photos and images into retro-style pixel art.
Random Wheel
Enter items and spin the wheel to choose one at random.
Ladder Game
Enter participants and outcomes, then follow the ladder to reveal each result.
Generators
Generate passwords, random numbers, random strings, UUIDs, and QR codes.
Password Generator
Create random passwords with length and character options.
Random Number Generator
Generate random numbers from a minimum, maximum, and count.
Random String Generator
Generate random strings with length and character options.
UUID Generator
Generate UUID v4 values in your browser.
QR Code Generator
Generate a QR code from text or a URL.
Developer Tools
Handle JSON, Base64, URL encoding, and CSV/JSON conversion tasks quickly.
Electronics Calculators
Calculate common electronics values such as Ohms law, voltage divider output, LED resistor values, battery life, RC/RL filters, and reactance.
Ohms Law Calculator
Calculate voltage, current, resistance, and power from any two known values.
LED Resistor Calculator
Calculate the series resistor needed for an LED circuit.
Voltage Divider Calculator
Calculate voltage divider output from Vin, R1, and R2.
Battery Life Calculator
Estimate battery runtime from capacity and current draw.
Resistor Color Code Calculator
Calculate 4-band resistor value and tolerance from colors.
Capacitance Converter
Convert capacitance values between pF, nF, µF, mF, and F.
Series and Parallel Resistor Calculator
Calculate the equivalent resistance of multiple resistors connected in series or parallel.
Filter Calculator
Calculate the cutoff frequency of RC and RL low-pass or high-pass filters using resistor, capacitor, and inductor values.
AWG Wire Size Converter
Convert AWG wire gauge to diameter, area, resistance per meter, and reference ampacity.
dBm to Watt Converter
Convert RF power values between dBm, mW, and W.
Frequency Wavelength Converter
Convert frequency and wavelength using the vacuum/air reference speed.
RC Time Constant Calculator
Calculate the RC time constant from resistor and capacitor values.
Reactance Calculator
Calculate capacitive or inductive reactance from frequency and component values.
Image Tools
Resize, compress, crop, rotate, watermark, mosaic, and convert images directly in your browser.
Image Resizer
Resize JPG, PNG, and WebP images directly in your browser.
Image Compressor
Reduce JPG, PNG, and WebP file size by adjusting image quality. Selected images are not uploaded to a server and are processed in your browser.
WebP Converter
Convert JPG and PNG images to WebP format.
Image Cropper
Select and resize a crop area directly on the image, or keep the full image and add background space to fit a new aspect ratio. Your image is not uploaded to a server.
Image Rotate and Flip
Rotate images in 90-degree steps, flip them, or adjust the angle one degree at a time with automatic canvas expansion.
Image Format Converter
Convert JPG, PNG/APNG, WebP, AVIF, GIF frame ZIP, BMP, SVG, HEIC, TIFF, and PNG-based ICO files in your browser.
Image Mosaic Tool
Select parts of an image with rectangle, circle, or brush modes and apply a mosaic pixelation effect directly in your browser. Your image is not uploaded to a server.
Image Watermark Tool
Add a text watermark to an image, customize the font, size, color, opacity, and rotation, and place it once or repeat it evenly across the image.
Image EXIF & Metadata Editor
View, edit, or selectively remove EXIF and metadata from JPG, HEIC, and HEIF photos.
Image Color Picker
Click an image to read pixel colors as HEX, RGB, and HSL.
Image Color Replacer
Select a color in a JPG, PNG, or WebP image and replace similar color areas with another color directly in your browser. Images are not uploaded to a server.
Make a Color Transparent
Make a selected color and similar areas in JPG, PNG, or WebP images transparent, then save the result as PNG or WebP. Images are processed in your browser.