All Tools
Free calculators, converters, text tools, electronics calculators, and image tools you can use without installation or sign-in. Each tool page includes instructions, examples, and FAQ.
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.
Salary Net Pay Calculator
Estimate monthly take-home pay from annual salary and deduction rate.
Converters
Convert temperature, length, weight, pyeong, and time values into the format you need.
Generators
Generate passwords, random numbers, random strings, UUIDs, QR codes, and lotto numbers.
Password Generator
Create random passwords with length and character options.
Random Number Generator
Generate random numbers from a minimum, maximum, and count.
Lotto Number Generator
Generate six random lotto numbers from 1 to 45.
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
Crop an image directly in your browser and download the selected area. Your image is not uploaded to a server.
Image Rotate and Flip
Rotate images by 90 degrees or flip them horizontally or vertically directly in your browser.
Image Format Converter
Convert JPG, PNG, and WebP images to another format directly in your browser and download the result.
Image Mosaic Tool
Select part of an image 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, adjust position, rotation, and opacity, then download it.
Remove Image Metadata
Re-save an image through browser canvas to remove most EXIF and metadata fields.
Image Color Picker
Click an image to read pixel colors as HEX, RGB, and HSL.