KoguNavi
Tools
A tiny toolbox for everyday cleanup tasks. Search by job, format, category, or whatever you have in mind.
Most tools are small, direct, and ready to use without an account. Privacy details stay easy to find when you need them.
Use cases
Showing 37 of 37 tools.
Recommended tools
Practical tools for Japanese text, forms, dates, copied text, and small everyday cleanup.
Environment-dependent / Machine-dependent Character Checker
Check Japanese compatibility characters before email, forms, or submission.
Line Break and Space Cleaner
Clean line breaks, spaces, tabs, and blank lines from copied text.
Full-width / Half-width Converter
Convert Japanese full-width and half-width text.
Japanese Era Converter
Convert dates between Gregorian years and Japanese eras.
Age Calculator
Calculate age, school years, and resume education-year hints.
CSV Mojibake Repair (Encoding Checker)
Repair garbled Japanese CSV files and export an Excel-friendly copy.
Date Duration & Business Days Calculator
Calculate date ranges and Japanese business days.
Password Generator
Generate random passwords with configurable length and character sets.
All tools
Text tools
7 tools
Environment-dependent / Machine-dependent Character Checker
Check Japanese compatibility characters before email, forms, or submission.
Line Break and Space Cleaner
Clean line breaks, spaces, tabs, and blank lines from copied text.
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.
Conversion tools
14 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.
Developer tools
13 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.
Image tools
3 tools