Free tools for everyday life and business — mortgage calculator, investment simulator, salary calculator, JSON formatter, password generator, and more. Everything runs in your browser. Your data is never sent externally.
Calculate monthly payments, total payments, and total interest for mortgages with equal payment or equal principal methods.
Simulate future asset value from monthly contributions and expected returns.
Simulate tax savings and investment returns from iDeCo and NISA contributions.
Calculate monthly payment, total payment, and total interest for car loans from interest rate and repayment period.
Simulate interest savings and term reduction from mortgage prepayments. Compare term-shortening and payment-reduction methods.
Calculate take-home pay after social insurance and taxes from gross annual salary.
Estimate old-age basic pension and employee pension amounts from enrollment period and average salary.
Calculate your maximum Furusato tax deduction based on income and family composition. Supports freelancers and side income.
Calculate estimated inheritance tax from total estate value and number of legal heirs. Shows basic deduction, taxable estate, and tax amount.
Calculate income tax and tax refund/payment from salary, side income, medical expense deductions, and more.
Calculate take-home amount after deducting retirement income deduction, income tax, and resident tax.
Calculate BMI from height and weight and assess obesity level based on Japan Society for the Study of Obesity standards.
Estimate body fat percentage from height, weight, age, and gender using the BMI method.
Suggests optimal wake-up or bedtimes based on 90-minute sleep cycles for refreshing mornings.
Calculate daily, monthly, and annual electricity costs from appliance wattage and usage time.
Manage focus with 25-minute work / 5-minute break Pomodoro technique. Custom settings supported.
Count characters, words, lines, and bytes in real-time. Supports full-width characters.
Format, minify, and validate JSON data in your browser.
Instantly encode and decode Base64 text in your browser. Supports multi-byte characters.
Generate SHA-1/SHA-256/SHA-384/SHA-512 hash values in your browser. Data is never sent to a server.
Encode and decode URLs in real-time. Supports Japanese URL conversion.
Convert between Unix timestamps and dates. Auto-detects seconds vs. milliseconds.
Compare two texts and highlight added and removed lines. Useful for code review and document comparison.
Test regex matching and replacement in real-time. Supports group capture inspection.
Convert between CSV and JSON in your browser. Supports header row auto-detection.
Easily generate and edit cron expressions with a GUI. Includes natural language descriptions and execution previews.
Read QR codes from image files. Supports JPEG, PNG, GIF, and WebP.
Compress and resize images in your browser. Nothing is uploaded to a server.
Convert between HEX, RGB, and HSL color codes. Includes an intuitive color picker.
Convert between units of length, weight, temperature, area, volume, speed, and data.
Merge, split, and compress PDF files in your browser. Data is never sent to a server.
Combine multiple images into a PDF. Save as PDF using your browser's print function.
Resize images by pixel, percentage, or social media presets. Supports aspect ratio lock. Data is never sent to a server.
Generate QR code-style pattern images from text or URLs. Downloadable as PNG.
Generate strong passwords using cryptographically secure random numbers.
Generate random numbers within a specified range and count. Supports no-duplicates and integer-only modes.
Calculate days, weeks, business days, and more between two dates.
Calculate your exact age, total days lived, days until next birthday, and zodiac sign from your date of birth.
Calculate tax-inclusive from tax-exclusive prices, or vice versa. Supports standard 10% and reduced 8% rates.