Price per 100g Comparison Tool (saruwakakun.com)
A unit price comparison tool that calculates the cost per 100g for multiple products and highlights the best deal. Handy for comparing different sizes or refill vs. regular packs at the supermarket.
BMI Calculator (saruwakakun.com)
A BMI calculator that takes height and weight as input and rates your result across five levels from underweight to obese. Also shows your ideal weight and the gap to reach it.
Gas Cost Calculator (saruwakakun.com)
A fuel cost calculator that estimates the gasoline expense for a drive based on fuel price, travel distance, and fuel efficiency. Includes tips on finding each value.
Discount Price Calculator (saruwakakun.com)
A discount price calculator that instantly computes the final price from the original price and a discount rate. Save multiple results to check the total discounted amount.
Sales Tax Calculator (saruwakakun.com)
A consumption tax calculator that computes the tax-inclusive price and tax amount from a pre-tax price. Supports the standard 10% rate and the reduced 8% rate for food and periodicals.
Countdown Timer (saruwakakun.com)
A web-based countdown timer that lets you set a duration or target date. Supports title and color customization, and URL sharing. No sign-up required.
Online Dice Roller (saruwakakun.com)
A free 3D dice roller that works instantly in the browser. Roll 1 to 6 dice simultaneously. Supports button clicks, spacebar, and Enter key. No personal data collected.
Chinese Zodiac & Age Reference (saruwakakun.com)
A reference table for looking up the Chinese zodiac sign (Eto/Junishi) by year. Lists the zodiac animal alongside the Western year, Japanese era, and age at a glance.
HTML Escape Tool (saruwakakun.com)
A web tool for escaping and unescaping HTML special characters (&, <, >, ", '). Optionally wraps output in <code> or <pre> tags. A handy utility for web developers.
Image Resizer (saruwakakun.com)
A browser-based bulk image resizer for JPEG, PNG, and GIF files. Resize while preserving aspect ratio, adjust quality, and download multiple images as a ZIP archive.
Character Counter (saruwakakun.com)
A simple character counter tool. Useful for checking character counts when there's a limit, or when you want to know the length of text you've written. Supports emoji and variant characters.
Bulk PNG/JPEG to WebP Converter (saruwakakun.com)
A browser-based bulk converter for PNG, JPEG, and GIF images to WebP format. Processed entirely locally with no server uploads. Converted images can be downloaded as a ZIP archive.
