Free Online Tools Collection

2026 Social Insurance Rates Applied! Simply enter your annual or monthly salary to automatically calculate National Pension, Health Insurance, Employment Insurance, and Income Tax deductions to show your net pay.

A healing web app to peacefully wind down your day. Features include 4-7-8 breathing meditation, gratitude journal, healing quotes, and worry release exercises.

Easily convert Jeonse (lump-sum deposit) to monthly rent and vice versa. Provides accurate calculations using the 2025 legal conversion rate (5.0%).

Easily manage daily work hours with a calendar-based interface. Set daily wages by job site, calculate overtime and night shift pay, and generate monthly settlements all in one place.

Track your gig work hours & pay with a calendar-based interface. Multiple job sites, overtime calculation, and monthly reports.

Calculate real-time exchange rates between Vietnamese Dong (VND) and Korean Won (KRW). Check your exchange amounts easily with an iPhone-style UI.

End your lunch menu dilemma! Random recommendation from 200 popular lunch menus. Have fun deciding your meal with a slot machine style interface.

Generate random Korean nicknames for games, SNS, and online communities. Create unique nicknames with adjective + noun combinations.

Calculate your International Age, Korean Age, and Zodiac sign from your date of birth. Also check the D-Day until your next birthday and how many days since you were born.

Calculate character count, word count, and byte count in real-time. Check with or without spaces and estimated reading time.

Calculate token counts and API costs for AI models like GPT-4 and Claude. Accurate token counting based on tiktoken.

Analyze romantic, friendship, and workplace compatibility between two people based on their MBTI types. Get scores, pros and cons, and advice for all 256 combinations.

Discover your daily fortune based on your Chinese zodiac sign from your date of birth. Check your overall fortune, financial fortune, love fortune, health fortune, and lucky numbers, colors, and directions.

Chat with MAX, the contrarian bot who disagrees with everything! A modern web recreation of the legendary 1993 DOS program. Includes typing speed test, format threat prank, and more fun features.

Discover your personality type with our accurate 48-question test. Get detailed analysis of your strengths, career aptitude, romance style, and compatibility.

Easily generate Linux server iptables firewall rules. Includes service presets for SSH, HTTP, HTTPS and advanced features like NAT and Rate Limiting.

Time is money! Calculate meeting costs in real-time based on average hourly rates by position. Check meeting efficiency without exposing individual salaries.

Easily generate Nginx web server configurations. Includes presets for WordPress, Node.js, PHP-FPM and advanced settings like SSL, reverse proxy, and gzip compression.

Enter two names and discover your compatibility score! Fun test for couples, friends, and colleagues. Share the results with anyone!

Transform your code into beautiful images. 8 themes, 10 gradient backgrounds, 19 programming languages supported. Create stunning code screenshots for social media sharing.

Format and validate JSON data beautifully. Features include tree view, syntax highlighting, and minification support.

Easily compare and convert timezones worldwide. Features city presets, multiple timezone comparison, and 12/24 hour format support.

How old are your ears? Test your hearing age with frequency-based hearing tests.

Test for red-green and blue-yellow color blindness with Ishihara-style plates.

How fast can you type? Measure your typing speed (WPM) and accuracy in English, Korean, or mixed mode.

Click as fast as you can when the screen turns green! Measure your average reaction time over 5 rounds and see your percentile rank.

Measure ambient noise levels in real-time using your microphone. Check decibel (dB) readings and safety ratings.

Test the frequency response of your headphones and speakers. Play various frequencies from 20Hz to 20kHz.

Find defective pixels on your monitor. Test with fullscreen solid colors and patterns to detect dead or stuck pixels.

Enjoy 6 interactive visual relaxation tools in one page: Breathing Guide, Particle Flow, Aurora Simulator, Eye Exercise, Zen Garden, and Mandala Drawing.

Explore 6 fractal patterns including Mandelbrot, Julia, and Burning Ship. Click to zoom infinitely and experience the endless beauty of mathematics.

Experience 6 interactive particle effects including fireworks, galaxy, and matrix with mouse and touch.

Convert images to ASCII text art. Supports multiple character sets and color/mono modes.

Instantly convert text or URLs to QR codes. Customize size & colors and download as PNG.

Generate secure passwords automatically. Configure length, character options, and check strength.

Calculate your BMI from height and weight. View weight categories with a visual gauge indicator.

Convert length, weight, temperature, area, and volume in real-time with bidirectional conversion.

Test regular expressions in real-time. Highlights matches, shows groups, and offers 12 presets.

Encode and decode text to Base64. Full UTF-8 support with real-time conversion.

Create beautiful CSS gradients visually. 15 presets with live preview and CSS code copy.