Tools
Use cases
Showing 61 of 61 tools.
All tools
Text tools
9 tools
Environment-dependent / Machine-dependent Character Checker
Check Japanese compatibility characters before email, forms, or submission.
Invisible Character Checker
Find hidden spaces, zero-width marks, and control characters.
Line Break and Space Cleaner
Clean line breaks, spaces, tabs, and blank lines from copied text.
Line Sort & Deduplicate
Sort a list and remove duplicate or blank lines.
Character / Word Counter
Count characters, words, lines, bytes, and Japanese writing estimates.
Japanese Punctuation Converter
Normalize Japanese punctuation, spaces, brackets, and dash variants.
Text Diff Checker
Compare two text snippets with line-by-line differences.
Markdown Live Preview
Write Markdown and preview the rendered page.
Markdown Table Generator
Build Markdown tables from an editable grid.
Calculators
5 tools
Japanese Consumption Tax Calculator
Split or add Japanese consumption tax with clear rounding options.
Percentage Calculator
Calculate ratios, percentage changes, discounts, and percent-of values.
Work Time Calculator
Calculate net work time and convert it to decimal hours.
Prorated Amount Calculator
Calculate a daily rate and prorated amount from a monthly price.
Profit Margin & Cost Ratio Calculator
Check profit, margin, cost ratio, markup, and a target selling price.
Conversion tools
18 tools
Base64 Encode / Decode
Encode and decode Base64 text, including Unicode characters.
URL Encode / Decode
Encode and decode URL components for query strings and copied links.
Full-width / Half-width Converter
Convert Japanese full-width and half-width text.
Kana Converter
Convert hiragana, katakana, and half-width kana.
Japanese Era Converter
Convert dates between Gregorian years and Japanese eras.
Unix Timestamp Converter
Convert Unix timestamps and date/time values.
Age Calculator
Calculate age, school years, and resume education-year hints.
Date Duration & Business Days Calculator
Calculate date ranges and Japanese business days.
Paid Leave & Long Weekend Planner
Find long weekends using confirmed Japanese holidays and up to ten paid leave days.
CSV Mojibake Repair (Encoding Checker)
Repair garbled Japanese CSV files and export an Excel-friendly copy.
Invoice Registration Number & Corporate Number Checker
Check invoice registration number format and corporate-number check digits.
Japanese Numeral Converter
Convert between Arabic numbers and Japanese numerals.
JSON / CSV Converter
Convert between JSON and CSV, including nested JSON columns.
Pasted Table to CSV
Split copied tables into CSV or TSV.
Japanese CSV & Roster Preflight Checker
Check Japanese roster columns for blanks, duplicates, and contact-format issues.
Phone & Postal Code Batch Formatter
Normalize Japanese phone numbers and postal codes in bulk.
Email & Distribution List Cleaner
Extract and deduplicate email addresses before sending or import.
Unit Converter
Convert common length, area, weight, volume, temperature, and data units.
Developer tools
15 tools
JSON Formatter
Format, validate, and beautify JSON.
SQL Formatter
Format SQL queries for review and sharing.
URL Inspector & Cleaner
Inspect URL parts and remove common tracking parameters before sharing.
Cron Expression Explainer
Explain standard 5-field cron expressions and upcoming runs.
Regex Tester
Test JavaScript regular expressions against sample text.
Ruby Regex Tester
Test Ruby-style regular expressions with an Oniguruma engine.
JWT / OIDC Token Decoder
Decode JWT header and payload claims for debugging.
AWS ARN Parser
Split AWS ARNs into service, region, account, and resource parts.
CIDR / Subnet Calculator
Calculate IPv4 CIDR ranges, usable IPs, and overlap checks.
UUID Generator
Generate UUID v4 values.
Hash Generator
Generate SHA hashes for text.
HTML Live Preview
Paste HTML and preview a sandboxed rendered page.
Password Generator
Generate random passwords with configurable length and character sets.
Excel Column Letter & Number Converter
Convert Excel column letters and numbers or count a column range.
Color Contrast Checker
Check a text and background color pair against WCAG contrast thresholds.
Image tools
3 tools
Music
4 tools
Small break
7 tools
Breathing Guide
Follow a simple visual breathing rhythm for a short pause.
Focus & Break Timer
Run a clean countdown for a short break or focused task.
Reaction Time Test
Measure your response to a visual cue across five quick rounds.
Sequence Memory
Watch a growing pattern and repeat it in the same order.
Number Memory
Remember a number, type it back, and move to a longer one.
Color Word Challenge
Choose the ink color while ignoring the color word.
Random Picker
Roll dice, pick a number, or shuffle and reveal a list.