All tools
EC・海外
SEO/AEO
- llms.txt GeneratorEnter your site name, summary, and a list of links to generate an llms.txt index file for AI agents, plus an llms-full.txt with full content included. Everything runs in your browser — nothing you enter is ever sent anywhere.
- Structured Data Validator | JSON-LD Required & Recommended FieldsPaste JSON-LD structured data to check its syntax and see, at a glance, which schema.org/Google-required and recommended properties are present or missing. Runs entirely in your browser — nothing is sent to a server.
テキスト処理
- Character Counter — Manuscript Pages & Social Media LimitsCount characters and lines in real time, plus a 400-character manuscript-page estimate and UTF-8 byte size. Check whether your text fits X, Threads, Instagram, LinkedIn or Bluesky limits, or any custom limit you set. Everything runs in your browser — nothing is ever sent anywhere.
- Emoji Picker — Search by Name or Meaning, Copy in One ClickSearch over 210 emoji across 9 categories (smileys, gestures, animals, food, and more) by name or keyword, and copy them in one click. Your search terms and copied emoji are processed entirely in your browser — nothing is ever sent anywhere.
- Full-width / Half-width Converter — Numbers, Letters & KatakanaConvert numbers, letters, katakana and spaces between full-width and half-width forms, all at once. Handles half-width katakana voiced marks correctly (e.g. ｶﾞ → ガ). Everything runs in your browser — nothing is ever sent anywhere.
- Kaomoji Maker — Browse by Emotion, Copy in One ClickSearch Japanese emoticons (kaomoji) across 12 emotion and mood categories — happy, sad, angry, shy, and more — by keyword or category, and copy any of them with one click. Your search terms and copied kaomoji stay in your browser and are never sent anywhere.
- Letter Case Converter — UPPERCASE, lowercase, Title Case & camelCaseConvert text between UPPERCASE, lowercase, Title Case and Sentence case, or convert identifiers to camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE. Everything runs in your browser — nothing is ever sent anywhere.
- Morse Code Converter — Text ⇔ Morse Code with Audio PlaybackConvert between text and International Morse code in both directions, and play the result as beeps. Everything runs in your browser — nothing is ever sent anywhere.
- Prompt Template Filler | Auto-detect {variables} and fill in the blanksPaste a prompt template containing {variables} or {{variables}} and this tool auto-detects them, builds a fill-in form, and assembles the finished prompt in real time with one-click copy. Templates can be saved in your browser and nothing is ever sent to a server.
- Remove Line Breaks & Spaces — Clean Up Text FormattingRemove or replace line breaks, strip tabs and half/full-width spaces, trim each line, and collapse repeated blank lines — all at once. Everything runs in your browser, and your text is never sent anywhere.
- Romaji / Katakana Converter | Convert Between Hiragana, Katakana and RomajiConvert freely between hiragana, katakana, and Hepburn-style romaji — useful for checking passport-style spelling of names and place names. Everything runs in your browser and your text is never sent anywhere.
- Sort & Deduplicate Lines | Sort, Remove Duplicates, Shuffle Text LinesSort lines of text ascending or descending, remove duplicate lines, or shuffle them into a random order — all for free. Also supports trimming whitespace, removing blank lines, and case-insensitive comparison. Everything runs in your browser and your text is never sent anywhere.
- Speech Time Calculator | How Long Will Your Script Take to Read Aloud?Paste your script and instantly see how long it takes to read aloud at slow, normal, and fast speaking rates. English is timed in words per minute (110/130/150 wpm), Japanese in characters per minute, and mixed-language scripts are handled automatically. Perfect for rehearsing speeches, presentations, and narration. Your text is processed entirely in your browser and never sent anywhere.
- Text Diff Checker | Highlight Differences Between Two TextsPaste two blocks of text and instantly see what was added and removed, highlighted inline. Switch between line-by-line and character-by-character comparison, and optionally ignore case or whitespace differences. Everything runs in your browser — your text is never sent anywhere.
ビジネス事務・お金
- Digital Hanko Stamp Maker (Personal Seal PNG)Turn a name into a round, Japanese personal-seal (hanko/inkan) style stamp image, entirely in your browser. Pick any ink color (vermillion red by default) and download it as a transparent PNG. The name you type is never sent anywhere.
- Loan Repayment Calculator (Equal Payment / Equal Principal)Calculate your monthly payment and total interest from a loan amount, annual interest rate, and repayment term. Supports Japan's two standard mortgage/loan repayment methods: equal payment (元利均等返済) and equal principal (元金均等返済). Everything runs in your browser — the amounts you enter are never sent anywhere.
- Japan Paid Leave Calculator | Statutory Grant Days & Remaining BalanceCalculate the statutory annual paid leave (yukyu) grant dates, granted days, and current remaining balance (accounting for the 2-year expiry) under Japan's Labor Standards Act Article 39, based on your hire date and employment category (full-time or part-time). Follows the official Ministry of Health, Labour and Welfare grant-day tables. Everything runs in your browser only — nothing is sent anywhere.
- Resignation & Paid Leave Scheduler | Calculate Your Last Office Day in JapanEnter your target resignation date (or the date you want to start using your remaining paid leave) and this tool calculates your last office day, the day your leave consumption starts, and your resignation date — following Japanese employment norms. It also shows the statutory 2-week notice rule and a typical company-notice-period reference. Everything runs in your browser; nothing is sent to a server. This is not legal advice.
変換・エンコード
- Base64 Converter — Encode & Decode TextEncode text to Base64, or decode Base64 back to text — with correct handling of emoji and other multi-byte UTF-8 characters. Supports the URL-safe variant for JWTs and URL parameters. Everything runs in your browser; nothing is ever sent anywhere.
- CSV Column EditorExtract, reorder and merge CSV columns. Combine "First name" and "Last name" into a single "Full name" column, or reshape a contact list before importing it elsewhere. Everything runs in your browser — your data is never sent anywhere.
- CSV ⇔ JSON ConverterConvert between CSV and JSON in either direction. Use dot notation in column headers (like user.name) to represent nested objects and arrays. Everything runs in your browser — your data is never sent anywhere.
- JWT Decoder | View Header & Payload in Your Browser (No Signature Verification)Paste a JWT (JSON Web Token) to instantly decode and view its header and payload. This tool does not verify signatures. Everything runs in your browser only — your token is never sent anywhere.
- Kanji Numeral & Daiji Converter (Japanese)This tool converts numbers into Japanese daiji (壱, 弐, 参…, the formal anti-fraud numerals used on gift envelopes, contracts and receipts) and standard kanji numerals (千二百三十四…). It's specifically for Japanese-language numeral conventions. Everything runs in your browser — nothing is ever sent anywhere.
- Markdown PreviewType or paste Markdown and see the HTML preview update instantly. Copy the generated HTML source when you're done. Everything runs in your browser — your Markdown is never sent anywhere.
- Number Base Converter — Binary, Octal, Decimal, HexConvert instantly between binary, octal, decimal and hexadecimal. Type a value into any of the four fields and the other three update automatically. Everything runs in your browser — nothing is ever sent anywhere.
- Unit Converter — Length, Weight, Temperature, Area & SpeedConvert units across five categories — length, weight, temperature, area, and speed — all at once. Enter a single value and see it instantly converted to every major metric and imperial unit. Everything runs in your browser; nothing is ever sent anywhere.
- URL Encoder — Encode & Decode URLs (Batch Supported)Encode text to a percent-encoded (URL-encoded) string, or decode it back to text. Supports batch processing of multiple lines at once, plus a choice between component-style (for query parameter values) and full-URI-style encoding. Everything runs in your browser; nothing is ever sent anywhere.
日付・計算
- Japanese Age, School Grade & Zodiac CalculatorCalculate age, Japanese school grade and Chinese/Japanese zodiac from a date of birth. This tool follows Japan's specific school-year cutoff (April 2) and the Japanese legal age-counting rule, so it's tailored to Japanese conventions rather than a generic age calculator. Everything runs in your browser — nothing is ever sent anywhere.
- Anniversary & Days Elapsed CalculatorCalculate how many days it's been since a start date — like the day you started dating, a wedding anniversary, or a birthday — and find upcoming milestones like the 100th day, 1000th day, or Nth anniversary. You can also work out what date is N days or N years from a start date. Everything runs in your browser, so the dates you enter are never sent anywhere.
- BMI CalculatorCalculate your BMI (body mass index) and healthy (standard) weight from your height and weight. Shows both the WHO (international) classification and Japan's JASSO classification. Everything runs in your browser — your height and weight are never sent anywhere. This is not medical advice; use it as a general guide only.
- Japanese Business Day CalculatorWork out business days in Japan with weekends and public holidays excluded — including substitute holidays. Find the date N business days out, or count the business days in a range. Everything runs in your browser; your dates are never sent anywhere.
- Japan Child & Childcare Support Levy Calculator (April 2026) | Monthly estimate by insurerEstimate your monthly and annual burden under Japan's new Child and Childcare Support Levy (starting April 2026), based on your health insurer type (Kyokai Kenpo, company health insurance union, mutual aid association, National Health Insurance, or the elderly medical system) and annual income, using figures published by the Children and Families Agency. Also see the projected FY2026-FY2028 system-wide average trend. Your income is processed entirely in your browser and never sent anywhere.
- Japan Consumption Tax Calculator (Invoice-Compliant)Convert between tax-included and tax-excluded amounts at Japan's 8% and 10% consumption tax rates. Enter multiple invoice lines and it rounds the tax once per rate, exactly as Japan's invoice system requires. Everything runs in your browser; your amounts are never sent anywhere.
- Date Difference CalculatorWork out the days, weeks, months and years between two dates, or find the date that's a set number of days, months, or years before or after a given date. Everything runs in your browser — your dates are never sent anywhere.
- Electricity Cost CalculatorCalculate the electricity cost of an appliance from its wattage and usage time. You enter your own per-kWh unit price from your utility bill, rather than the tool assuming any specific utility's rate. Includes rough wattage presets for common appliances like refrigerators and air conditioners. All calculations run in your browser, so nothing you enter is sent anywhere.
- Japanese Era Year Converter (Wareki ⇔ Gregorian)Convert between the Japanese era calendar (Meiji, Taisho, Showa, Heisei, Reiwa) and the Gregorian calendar, down to the exact day. Correctly handles era-boundary dates (e.g. Showa 64 = Jan 7, 1989 vs Heisei 1 = Jan 8, 1989) and shows the current age for the converted date. Everything runs in your browser — the date you enter is never sent anywhere.
- Holiday Bridge Planner | Longest Consecutive Days Off in JapanEnter a date range and how many paid-leave days you have, and this tool finds the top 5 ways to place your leave around Japan's weekends and public holidays to create the longest possible streak of consecutive days off — useful for planning around Golden Week, Obon, or New Year. Everything runs in your browser; nothing is sent to a server.
- Hourly Wage & Overtime Pay Calculator | Convert Monthly Salary to Hourly Rate (Japan)Convert your monthly salary to an hourly rate and estimate overtime pay using Japan's statutory minimum premium rates for overtime, holiday, and late-night work. This tool is based on Japanese labor law and is intended for employees working under Japanese employment rules. Everything is calculated in your browser only — nothing is sent anywhere.
- Japan Income Wall Simulator 2026 | Check the ¥1.06M / ¥1.3M / ¥1.78M thresholdsBased on Japan's current 2026 rules, see how far your annual income is from the ¥1.06 million social-insurance threshold, the ¥1.3 million dependent threshold, and the ¥1.78 million income-tax threshold, and what changes if you cross each one. Your numbers are processed entirely in your browser and never sent anywhere.
- Percentage & Discount CalculatorCalculate percentages, discounted prices, and rates of change all in one place. Covers common cases like "what percent of B is A", "what's the discounted price of B", and "what's the percentage change from A to B". Everything runs in your browser — the numbers you enter are never sent anywhere.
- Pregnancy Due Date CalculatorEstimate your due date and current week of pregnancy from your last menstrual period or ovulation date. Everything runs in your browser — your dates are never sent anywhere. This is an estimate, not medical advice.
- Sleep Cycle CalculatorWork out the best bedtime for a target wake-up time, or the best wake-up time if you're going to sleep now, based on 90-minute sleep cycles. Everything runs in your browser — your times are never sent anywhere.
- Split Bill CalculatorSplit a total bill among a group and see exactly how much each person pays. Supports plain even splits as well as weighted splits (e.g. the organizer pays less). Rounds to the nearest 1, 10, or 100, and spreads any leftover fairly instead of dumping it on one person. Everything runs in your browser — the amounts you enter are never sent anywhere.
- Sunrise & Sunset CalculatorCalculate sunrise, sunset, and solar noon times for any location and date. Choose from presets for all 47 Japanese prefectural capitals, or enter latitude and longitude directly. Useful for planning photography, fishing, and hiking. All calculations run in your browser, so the location and date you enter are never sent anywhere.
- World Clock & Time Zone ConverterEnter one date and time for a base city, and instantly see the local time, time difference, and whether it falls within business hours for several comparison cities at once. Daylight saving time is resolved correctly for each date using your browser's built-in time zone database — no stale fixed-offset table. Everything runs in your browser; the date and time you enter are never sent anywhere.
生活・住まい
- Clothing Size Converter — US, EU, UK, JPConvert tops sizes (t-shirts, shirts, jackets) between US, EU, UK, JP and International (XS-XL). Pick your men's or women's size in any one system and the rest are shown automatically. Everything runs in your browser — nothing is ever sent anywhere.
- Pet Age Calculator (Dog & Cat Years to Human Years)Convert your dog or cat's age to human years using the AVMA's (American Veterinary Medical Association) non-linear, size-adjusted method — not the outdated 'multiply by 7' rule. Everything runs in your browser, so the age you enter is never sent anywhere.
- Shoe Size Converter — cm to US, EU, UKConvert shoe sizes between foot length (cm) and US, UK, EU sizing. Pick men's, women's or kids' sizing, then enter your cm or select a US/UK/EU size and the rest are shown automatically. Everything runs in your browser — nothing is ever sent anywhere.
生活・遊び
- Amidakuji Generator (Ghost Leg Lottery) | Free Online ToolEnter participant names and outcomes (prizes, roles, tasks), and instantly generate a random amidakuji (Japanese "ghost leg" ladder lottery) that guarantees a fair one-to-one match for every participant. Great for picking who does what, party games, or drawing lots. Everything runs in your browser — nothing you type is sent anywhere.
- Anagram GeneratorRearranges the letters of the text you enter and lists the resulting anagram candidates. Works with Latin letters, digits, and non-Latin scripts alike. Everything runs in your browser, so the text you enter is never sent anywhere.
- Bingo Card Generator | Printable Number & Word Bingo CardsGenerate as many printable bingo cards as you need — classic number bingo (75-ball, 5x5, free center) or a custom word/theme bingo. Great for parties, office events, and classroom icebreakers. Everything runs in your browser; nothing is sent anywhere.
- Birthday CountdownEnter a birthday to see the days, hours, minutes, and seconds until the next birthday, plus the age you'll turn. The result is reflected in the URL, so you can share the link as-is. Everything runs in your browser, so the date you enter is never sent anywhere.
- Disaster Stockpile CalculatorEnter your household size and number of days to calculate the drinking water, food, and portable-toilet supplies you need. Based on figures published by the Tokyo Metropolitan Government. Nothing you enter is sent anywhere.
- Countdown Page Generator — Set a Title & Date, Share by URLCreate a countdown page for a product launch, event, deadline, or anything else by setting a title and target date. Everything is stored in the page URL — no account and no server-side storage — so sharing the link shows the same countdown to whoever opens it.
- Decision Roulette — Enter Options, Spin to Pick OneLet a spinning wheel decide where to eat, whose turn is next, or who gets the dare. Enter your options and spin — a cryptographically secure random number picks one fairly. Runs entirely in your browser; nothing is ever sent anywhere.
- Dice & Coin Flip | Set Count and Sides, Free in Your BrowserRoll dice (d4-d20 or a custom side count, 1-12 dice) and flip coins (1-100 flips, with a heads/tails tally), all randomly generated in your browser. Nothing is sent to any server.
- Fan Sign Text Maker (Uchiwa Text)Create bold, oversized text for a Japanese-style concert fan sign (uchiwa) with your idol's name or a cheer message. Pick your text color, background color, and outline, then download it as a PNG. Everything runs in your browser, so nothing you type is ever sent anywhere.
- Funny Award Certificate MakerCreate a funny award certificate for office parties, year-end parties, or team events in seconds. Enter a recipient name, award title, body text, date, and issuer, and see a certificate-style layout update live. Download it as a PNG image. Everything runs in your browser only — nothing you type is ever sent anywhere.
- Japanese Gift Money Guide (Goshugi & Koden)A guide to Japan's cash-gift customs for weddings (goshugi) and funerals (koden). Pick a relationship to see the typical amount range and etiquette (new vs. used bills, amounts to avoid) commonly followed in Japan. Nothing you select is sent anywhere.
- Kairanban Notice Maker | Fill in the blanks for a Japanese neighborhood circularChoose from 5 common Japanese neighborhood-association (kairanban) notice types — cleanup day, general meeting, garbage rule changes, summer festival, and safety alert — fill in the date, place, and contact details, and get a finished notice written in the real formal conventions used in Japan (opening greeting, itemized 'ki' section, closing 'ijo'), ready to copy or print. Everything runs in your browser; nothing is sent anywhere.
- Name Board MakerCreate a tall name board with your idol's name or a cheer message, the kind fans hold up at Japanese concerts and events. Choose text and background colors plus a frame style (none, single, or double border), then download it as a PNG. Everything runs in your browser, so nothing you type is ever sent anywhere.
- Noshi Envelope Cover-Text Preview (Japanese Gift Envelopes)Pick an occasion — a wedding gift, a birth celebration, a condolence payment, and more — enter a name, and see a preview of a correctly worded Japanese noshi envelope (ご祝儀袋/香典袋), complete with the right knot style and ink color. Everything runs in your browser; the name you type is never sent anywhere.
- Omikuji (Japanese Fortune Slip) | Free, One-Tap, Save as ImageOmikuji is a traditional Japanese fortune-telling slip drawn at shrines and temples. Tap once to draw a fortune, from Great Blessing to Curse, using odds based on a real shrine's published ratio. Save your result as a PNG image. Everything runs in your browser and nothing is sent anywhere.
- Oshi Color Palette MakerEnter your favorite color (its hex code) and instantly generate tints, shades, a complementary color, analogous colors, and a triadic color scheme — each with ready-to-copy HEX, RGB, and HSL codes. Check the contrast ratio (WCAG) between text and background colors too. Nothing you enter is ever sent anywhere.
- Pomodoro Timer | 25-Minute Work / 5-Minute Break Focus TimerA free Pomodoro Technique timer: 25 minutes of work followed by a 5-minute break, with a longer break every 4 sets. All durations are adjustable. Browser notifications and a sound alert let you know when a phase changes. Everything runs in your browser only — nothing is sent anywhere.
- Profile Card Maker | Create a Free Self-Introduction Card (PNG)Enter your name, intro, favorites, and SNS IDs, pick a generic template, and create a profile card (self-introduction card) you can download as a PNG. No account needed. Everything is processed entirely in your browser and never sent anywhere.
- QR Code GeneratorGenerate a QR code from a URL, plain text, WiFi network, or contact card (vCard) — instantly, with no expiration and completely free. Everything runs in your browser, so nothing you enter is ever sent anywhere.
- Random Winner Picker — Weighted, No-Repeat, Multiple WinnersFairly draw winners for a giveaway or event from a list of entrants, with optional weighting. No-repeat drawing is the default (no one is picked twice), and you can select multiple winners at once. See this session's draw history right on the page. Runs entirely in your browser — your entrant list is never sent anywhere.
- Reward Sticker Chart Maker | Printable Minimalist Charts for AdultsSet a goal and a number of days (7, 14, 30 or custom) to generate a clean, adult-friendly reward sticker chart ready for A4 printing. Fits standard 20mm round stickers. Great for habit tracking. Everything runs in your browser — nothing is sent to a server.
- Team Shuffler & Seat Assigner | Randomly Split a Name ListPaste a list of names and randomly split it into evenly-sized groups, or assign names to a seating grid (rows x columns). Useful for classroom groupings, seat changes, and party table assignments. Everything runs in your browser — the list is never sent anywhere.
- Tier List Maker | Free S/A/B/C/D Ranking Chart CreatorAdd text or image items and drag them into an S/A/B/C/D tier list, then save the finished ranking chart as a PNG image. Tier count and labels are fully customizable. Everything runs in your browser — nothing you add is ever sent anywhere.
- Tournament Bracket Maker | Auto-generate a single-elimination bracket from a list of namesEnter participant names and instantly generate a single-elimination tournament bracket. Byes are assigned automatically when the number of participants isn't a power of two. Click a name to record a winner and it advances to the next round automatically. Print the bracket to post at your venue. Everything runs in your browser — participant names are never sent anywhere.
画像
開発者
- Cron Expression Generator | GUI Builder & Next Run TimeBuild a cron expression from five fields or by editing it directly, validate the syntax instantly, and see the next 5 run times. Runs entirely in your browser — nothing is sent to a server.
- Hash Generator — MD5, SHA-1, SHA-256, SHA-384, SHA-512Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text or a file, all at once. Useful for verifying file integrity or checksums. Everything runs in your browser — your text and files are never sent anywhere.
- JSON Formatter & Validator | Minify, Beautify, and Detect Syntax ErrorsFormat JSON with 2/4-space or tab indentation, or minify it, and see syntax errors with the exact line and column where they occur. Everything runs in your browser only — your JSON is never sent anywhere.
- Password Generator — Custom Rules & Strength MeterGenerate secure random passwords with a chosen length and character types (uppercase/lowercase/digits/symbols), 1 to 20 at once, with an entropy (bit) score and strength label. Everything runs in your browser using crypto.getRandomValues() — nothing is ever sent anywhere.
- Regex Tester | JavaScript Pattern Matching & Capture GroupsTest JavaScript regular expressions instantly, see highlighted matches, and inspect numbered and named capture groups. Everything runs in your browser only — your pattern and text are never sent anywhere.
- Unix Timestamp Converter | Epoch to Date & TimezoneConvert Unix timestamps (epoch seconds or milliseconds) to and from human-readable dates, with UTC, your local timezone, and any IANA timezone. Runs entirely in your browser — nothing is sent to a server.
- UUID Generator — Bulk v4 & v7Generate RFC 9562-compliant UUID version 4 (random) or version 7 (time-ordered, sortable) in batches of 1 to 100. Toggle uppercase and hyphens. Everything runs in your browser — nothing is ever sent anywhere.