# 4pm Tools

> Pure Client-Side Free Online Web Utilities & Developer Tools. Over 113 privacy-focused, browser-only web applications with zero telemetry, zero remote server uploads, and instant performance.

Website: https://4pm.jp
Version: 2.0.0
License: Free to use, unlimited, no sign-up required.
Full Documentation: https://4pm.jp/llms-full.txt

## Overview & Architecture
4pm Tools is a comprehensive collection of 113 web applications running 100% locally inside the user's web browser using standard HTML5, CSS3, JavaScript, Web Crypto API, and Web Audio API.

### Privacy & Security Guarantees
- **Zero Server Uploads**: Calculations, image transforms, code formatting, file splitting, cryptography, and audio generation execute solely within browser memory (client-side JS).
- **Confidentiality**: Safe for proprietary source code, API keys, passwords, database dumps, and private personal photos.
- **Zero Telemetry**: No third-party tracking cookies or surveillance.
- **Offline Readiness**: Once loaded, all tools continue functioning without an active network connection.
- **Global Accessibility**: Multilingual support for 9 languages (Japanese, English, Chinese Simplified/Traditional, Spanish, German, French, Korean, Portuguese).

## Complete Tools Catalog (113 Tools)

### Life & Finance (生活・マネー)
- [Bill Split & Tip Calculator](https://4pm.jp/split/): Split dinner bills evenly or with custom weights, round off fractional amounts, and calculate tips easily. (Keywords: bill splitter, split the bill, tip calculator, split expense)
- [Sales Tax & VAT Calculator](https://4pm.jp/tax/): Calculate 8% reduced and 10% standard consumption tax, including tax-inclusive and tax-exclusive amounts. (Keywords: consumption tax, vat calculator, sales tax, tax inclusive)
- [Discount & Sale Calculator](https://4pm.jp/discount/): Calculate final sale prices with percent off, flat discounts, and rewards points cashback savings. (Keywords: discount calculator, sale calculator, percent off, price markdown)
- [Loan & Mortgage Calculator](https://4pm.jp/loan/): Simulate monthly mortgage and loan payments, interest breakdown, and amortization in real time. (Keywords: mortgage calculator, loan calculator, monthly payment, interest rate)
- [Age & Birthday Calculator](https://4pm.jp/age/): Calculate exact age, Chinese zodiac, western horoscope, days until birthday, and school graduation timeline. (Keywords: age calculator, birthday calculator, zodiac, graduation year)
- [Date Duration & D-Day Counter](https://4pm.jp/date/): Count days between two dates, calculate target date after N days, and count down to upcoming milestones. (Keywords: days between dates, date calculator, d-day counter, days countdown)
- [Sleep Cycle Calculator](https://4pm.jp/sleep/): Find optimal bedtimes and wake-up times aligned with 90-minute sleep cycles to wake up feeling refreshed. (Keywords: sleep cycle calculator, sleep calculator, wake up time, bedtime)
- [Work Hours & Time Calculator](https://4pm.jp/time-calc/): Calculate daily working hours, deduct lunch breaks, and add/subtract time durations effortlessly. (Keywords: work hours calculator, time card calculator, time duration, payroll hours)
- [Calendar & Japanese Era Table](https://4pm.jp/cal/): Interactive monthly calendar with Japanese era (Reiwa, Heisei, Showa) and Western year cross-reference table. (Keywords: calendar, japanese era, reiwa to western, year converter)
- [Business Apology & Excuse Generator](https://4pm.jp/apology/): Generate professional business apology emails and polite excuses for late replies, delays, rescheduling, and unexpected issues. (Keywords: business apology, excuse generator, email excuse, late apology email)
- [Kanji Number & Formal Receipt Converter](https://4pm.jp/kanji-num/): Convert numbers into Japanese Kanji, formal legal Daiji (壱, 弐, 参) for receipts/checks, and spelled-out numerals. (Keywords: kanji numbers, daiji converter, japanese legal numerals, receipt kanji)
- [Business Email Signature Generator](https://4pm.jp/email-sig/): Generate polished business email signatures with multiple decorative border templates in plain text and HTML format. (Keywords: email signature generator, business signature, email template, signature maker)

### Developer & Coding (開発ツール)
- [JSON Formatter & Validator](https://4pm.jp/json/): Format, validate, prettify, sort keys, and minify JSON data instantly in your browser. (Keywords: json formatter, json validator, json minify, json parser)
- [Regex Tester & Cheat Sheet](https://4pm.jp/regex/): Test and debug regular expressions in real-time with capture group extraction, flags, and replacements. (Keywords: regex tester, regular expression, regex replace, regex cheatsheet)
- [JWT Debugger & Inspector](https://4pm.jp/jwt/): Decode and inspect JSON Web Tokens (JWT) headers, payloads, and timestamps with full privacy. (Keywords: jwt debugger, jwt decoder, json web token, jwt inspector)
- [SQL Formatter & Beautifier](https://4pm.jp/sql/): Beautify, indent, and format messy SQL queries with uppercase keyword support and minification. (Keywords: sql formatter, sql beautifier, format sql, sql indent)
- [HTML Entity Encoder / Escaper](https://4pm.jp/html/): Escape/unescape HTML entities (<, >, &, ", ') and strip HTML tags to clean plain text. (Keywords: html escape, html entity encoder, html unescape, strip html tags)
- [Markdown Live Editor & Preview](https://4pm.jp/md/): Live Markdown editor with real-time HTML preview, table support, and HTML / Markdown export. (Keywords: markdown editor, markdown preview, markdown to html, live markdown)
- [Placeholder Image & Mockup Generator](https://4pm.jp/placeholder/): Generate instant lightweight SVG or PNG placeholder dummy images with custom dimensions, colors, and custom text labels. (Keywords: placeholder image generator, dummy image, mockup placeholder, svg placeholder)
- [Visual CSS Button & Box UI Generator](https://4pm.jp/css-btn/): Visually design modern CSS buttons and cards with gradients, custom box-shadows, border-radius, and hover animations with one-click code export. (Keywords: css button generator, css styler, box shadow generator, button designer)
- [Sorting Algorithm Visualizer (Bubble, Quick, Merge...)](https://4pm.jp/sort-vis/): Visualize and listen to sorting algorithms in real time: Bubble, Selection, Insertion, Quick, Merge, and Heap Sort with sound and stats. (Keywords: sorting visualizer, sort algorithm, bubble sort, quick sort)
- [Search & Pathfinding Visualizer (Binary, BFS, DFS, A*)](https://4pm.jp/search-vis/): Compare Linear vs Binary Search on 1D arrays, and visualize 2D grid pathfinding algorithms including BFS, DFS, Dijkstra, and A* in real time. (Keywords: search visualizer, pathfinding, binary search, a star algorithm)
- [Conway's Game of Life Cellular Automaton](https://4pm.jp/life/): Conway's classic cellular automaton simulating artificial life. Explore gliders, glider guns, pulsars, and spaceships on an interactive grid. (Keywords: game of life, cellular automaton, conway, simulation)
- [Interactive Fractal & Mandelbrot Explorer](https://4pm.jp/fractal/): Explore mathematical self-similarity with interactive Mandelbrot sets, recursive fractal trees, Koch snowflakes, and Sierpinski triangles. (Keywords: fractal generator, mandelbrot set, fractal tree, koch snowflake)
- [N-Gram & TF-IDF Natural Language Processing Explorer](https://4pm.jp/tfidf/): Interactive natural language processing analyzer for character/word N-grams and TF-IDF document keyword importance ranking. (Keywords: tf idf, n gram, nlp analyzer, term frequency)
- [CSS Keyframe Animation Generator](https://4pm.jp/css-anim/): Visual timeline GUI tool to design complex CSS keyframe animations with transforms, easing curves, and export clean CSS. (Keywords: css animation, keyframe generator, css transform, animation maker)
- [Modern CSS Snippets & Layout Templates](https://4pm.jp/css-templates/): Ready-to-use modern CSS snippets and layout templates including glassmorphism, responsive grids, buttons, and visual cards. (Keywords: css templates, css snippets, web components, glassmorphism)
- [Programming Boilerplate & Magic Words Hub](https://4pm.jp/boilerplate/): Starter boilerplate templates and explanations of entry-point 'magic words' for C, Java, Python, Rust, Go, JavaScript, HTML5, and more. (Keywords: programming boilerplate, starter code, magic words, code template)

### Security, Privacy & Encryption (暗号・セキュリティ)
- [Base64 Encoder / Decoder](https://4pm.jp/base64/): Encode and decode text, files, and images to/from Base64 and Data URLs entirely in your browser. (Keywords: base64 encode, base64 decode, base64 converter, data url)
- [URL Encoder & Parser](https://4pm.jp/url/): Encode/decode URLs, parse URL components, and view/edit query string parameters effortlessly. (Keywords: url encode, url decode, url parser, query string)
- [Hash & HMAC Generator](https://4pm.jp/hash/): Generate SHA-256, SHA-512, SHA-1, MD5, and HMAC hashes securely using the browser Web Crypto API. (Keywords: hash generator, sha256, sha512, md5 hash)
- [UUID & Unique ID Generator](https://4pm.jp/uuid/): Generate cryptographic UUID v4, UUID v7, and unique alphanumeric IDs in bulk with custom formatting. (Keywords: uuid generator, uuid v4, uuid v7, guid generator)
- [Strong Password Generator](https://4pm.jp/pass/): Generate strong, secure passwords and passphrases using crypto-secure random generators. (Keywords: password generator, secure password, random password, passphrase)
- [PII & Secret Text Redactor / Masker](https://4pm.jp/mask/): Automatically detect and redact emails, phone numbers, IP addresses, and sensitive digits with asterisks or custom mask strings. (Keywords: pii redactor, text masking, redact personal info, mask phone email)
- [Phishing Site Spotter & Defense Trainer](https://4pm.jp/phishing-sim/): Spot the hidden red flags in simulated deceptive phishing login pages and emails. Interactive security awareness training for safe browsing. (Keywords: phishing simulator, spot phishing, security awareness, fake login detector)

### Text Processing & Formatting (テキスト操作)
- [Text Diff Checker](https://4pm.jp/diff/): Compare two text snippets side-by-side or unified to highlight additions, deletions, and differences. (Keywords: text diff, diff checker, compare text, file diff)
- [Text Case Converter](https://4pm.jp/case/): Convert text between camelCase, snake_case, kebab-case, PascalCase, UPPERCASE, lowercase, and title case. (Keywords: case converter, camelcase, snake_case, kebab-case)
- [Text & Character Counter](https://4pm.jp/text/): Count characters, words, lines, bytes, estimated reading time, and analyze text frequency in real time. (Keywords: word counter, character counter, text analyzer, line counter)
- [Dummy Text & Lorem Generator](https://4pm.jp/lorem/): Generate classic Latin Lorem Ipsum or natural Japanese placeholder text by paragraphs, words, or lists. (Keywords: lorem ipsum, dummy text, placeholder text, text generator)
- [CSV to JSON & Table Converter](https://4pm.jp/csv/): Convert CSV/TSV to JSON and vice-versa, inspect data in a formatted HTML table, and export results. (Keywords: csv to json, json to csv, tsv converter, csv table viewer)
- [Japanese Kana & Width Converter](https://4pm.jp/kana/): Convert between Japanese Hiragana, Full-width Katakana, and Half-width Katakana seamlessly. (Keywords: kana converter, hiragana to katakana, half-width katakana, japanese converter)
- [Morse Code Translator & Audio](https://4pm.jp/morse/): Translate text to Morse code and decode Morse code back to text with real-time audio playback tone. (Keywords: morse code translator, text to morse, morse audio, morse decoder)
- [Line Prefix, Suffix & Numbering Tool](https://4pm.jp/prefix/): Batch append prefix, suffix, quotes, commas, or incremental numbering (e.g., 01., [1]) to every line of text. (Keywords: line prefix, line suffix, add prefix, line numbering)
- [Deduplicate, Sort & Clean Lines](https://4pm.jp/dup/): Remove duplicate lines, filter out empty rows, trim whitespace, and sort alphabetically or numerically with case sensitivity controls. (Keywords: remove duplicate lines, deduplicate list, sort lines, unique lines)
- [Bionic Reading Text Converter](https://4pm.jp/bionic/): Format text with bolded initial letters to guide the eyes and allow your brain to read and comprehend faster with less fatigue. (Keywords: bionic reading generator, speed reading formatter, reading assistant, bionic text)
- [Braille Translator & 6-Dot Visualizer](https://4pm.jp/braille/): Convert Japanese kana, alphabet, and numbers to Unicode Braille and back with a 6-dot visual representation. (Keywords: braille translator, braille converter, unicode braille, braille chart)

### Math, Units & Conversions (計算・単位変換)
- [Base Converter & Programmer Calc](https://4pm.jp/calc/): Convert between Binary, Octal, Decimal, and Hexadecimal with real-time bitwise operations. (Keywords: base converter, hex to decimal, binary converter, bitwise calculator)
- [Universal Unit Converter](https://4pm.jp/unit/): Convert units of length, mass/weight, data storage, temperature, and speed accurately. (Keywords: unit converter, length converter, weight converter, data size converter)
- [UNIX Timestamp & Timezone](https://4pm.jp/time/): Convert UNIX timestamps (seconds/ms) to human dates, view global time zones and ISO8601 strings. (Keywords: unix timestamp, epoch converter, time zone converter, iso 8601)
- [Cron Expression Parser & Schedule](https://4pm.jp/cron/): Parse and translate 5/6-part cron expressions into human-readable descriptions and preview next execution dates. (Keywords: cron parser, cron expression, crontab generator, cron schedule)
- [Aspect Ratio & Resolution Calculator](https://4pm.jp/aspect/): Calculate aspect ratios (16:9, 4:3, 21:9, golden ratio), find missing dimensions, and generate CSS aspect-ratio. (Keywords: aspect ratio calculator, screen resolution, 16:9 ratio, image dimensions)
- [BMI & Calorie Health Calculator](https://4pm.jp/bmi/): Calculate BMI, ideal body weight, BMR (Basal Metabolic Rate), and daily calorie needs based on age and activity. (Keywords: bmi calculator, ideal body weight, bmr calculator, calorie calculator)

### Design, Colors & Media (デザイン・画像)
- [Color Picker & Contrast Checker](https://4pm.jp/color/): Color picker with HEX/RGB/HSL/CMYK conversion, WCAG 2.1 contrast ratio checker, and palette variations. (Keywords: color picker, contrast checker, hex to rgb, wcag contrast)
- [QR Code Generator & Scanner](https://4pm.jp/qr/): Generate custom QR codes (PNG/SVG) from text/URL, and scan/decode QR codes from image files or camera. (Keywords: qr code generator, qr code scanner, qr reader, create qr code)
- [Image Resizer & Format Converter](https://4pm.jp/img/): Resize, compress, and convert images between PNG, JPEG, and WebP using client-side Canvas. 100% private. (Keywords: image resizer, image compressor, webp converter, png to jpeg)
- [SVG Viewer & Data URI Converter](https://4pm.jp/svg/): Live SVG code previewer, minify/beautify SVG markup, generate CSS Data URIs, and export to PNG. (Keywords: svg viewer, svg to data uri, svg to png, svg previewer)
- [Doodle & Signature Canvas](https://4pm.jp/draw/): Draw sketches or create digital signatures with touch/mouse support. Export as transparent PNG. (Keywords: signature pad, digital signature, drawing canvas, doodle pad)
- [Photo Exif & Privacy Inspector](https://4pm.jp/exif/): Inspect camera settings, shooting date, and GPS location metadata embedded in image files privately. (Keywords: exif viewer, photo metadata, image gps, camera settings)
- [Local Font Comparison & Inspector](https://4pm.jp/font/): Preview custom text side-by-side using fonts installed on your local computer to compare typography and weights without installing software. (Keywords: font comparator, local font preview, typography previewer, installed fonts test)
- [ASCII Art Generator & Image Converter](https://4pm.jp/ascii/): Convert images to ASCII text art with customizable character sets, resolution, and contrast. Includes big text font banner generator. (Keywords: ascii art generator, image to ascii, text art, ascii converter)
- [Color Palette Generator & Harmony Explorer](https://4pm.jp/palette/): Generate harmonious color palettes based on color theory (analogous, complementary, triadic, monochromatic, and UI themes) from any seed color. (Keywords: color palette, palette generator, color harmony, complementary colors)
- [Color Blindness Simulator & Accessibility Checker](https://4pm.jp/color-blind/): Simulate how images and color combinations appear to individuals with Protanopia, Deuteranopia, Tritanopia, and Achromatopsia for accessible design. (Keywords: color blindness simulator, protanopia, deuteranopia, tritanopia)

### Everyday Utilities (ユーティリティ)
- [Quick Notepad & Autosave](https://4pm.jp/memo/): Fast, distraction-free browser notepad with automatic local storage autosave, character count, and text export. (Keywords: online notepad, autosave memo, browser scratchpad, quick notes)
- [Simple ToDo & Checklist](https://4pm.jp/todo/): Minimalist task manager and checklist with progress tracker and persistent local storage saving. (Keywords: todo list, task checklist, daily planner, task tracker)
- [Stopwatch & Pomodoro Timer](https://4pm.jp/timer/): Feature-rich stopwatch with lap times, countdown timer, and Pomodoro focus timer with Web Audio alerts. (Keywords: stopwatch, pomodoro timer, countdown timer, lap timer)
- [Multi Tally Counter](https://4pm.jp/counter/): Create multiple customizable tally counters with step increments, keyboard shortcuts, and local persistence. (Keywords: tally counter, click counter, multi counter, count tracker)
- [Reaction Time Speed Tester](https://4pm.jp/reaction/): Test your reflexes and visual reaction time in milliseconds when the red screen turns green. (Keywords: reaction time test, reflex tester, click speed test, benchmarking reflexes)
- [Spin the Wheel & Decision Maker](https://4pm.jp/wheel/): Customizable spinning wheel decider for picking lunch, lottery winners, and daily random choices. (Keywords: spin the wheel, decision roulette, random wheel picker, wheel decider)
- [Random Picker, Dice & Coin Flip](https://4pm.jp/coin/): Pick random items from a custom list, flip coins, and roll multi-sided dice with engaging animations. (Keywords: random picker, coin flipper, dice roller, random decider)
- [Typing Speed Test (WPM / CPM)](https://4pm.jp/speed/): Test your typing speed (WPM/CPM) and accuracy with real-time feedback and detailed performance stats. (Keywords: typing test, typing speed, wpm test, cpm test)
- [Dead Pixel & Screen Uniformity Checker](https://4pm.jp/screen/): Full-screen solid color test (RGB, White, Black) to inspect monitors for dead or stuck pixels, burn-in, and backlight uniformity. (Keywords: dead pixel test, screen uniformity, stuck pixel checker, monitor test)
- [RSVP Rapid Serial Visual Presentation Reader](https://4pm.jp/rsvp/): Read text rapidly without moving your eyes by flashing words one at a time at speeds up to 1000 WPM in a fixed focal point. (Keywords: rsvp reader, speed reader app, rapid serial visual presentation, flash reader)
- [Always-on-Top Floating Clock & Sticky Note](https://4pm.jp/pip/): Keep a digital clock, stopwatch, timer, or short note always-on-top on your desktop using browser Picture-in-Picture mode. (Keywords: picture in picture clock, always on top clock, pip floating timer, floating sticky note)

### Audio & Music Tools (音楽・サウンド)
- [Ambient White Noise Generator](https://4pm.jp/noise/): Generate soothing White, Pink, and Brown ambient noise locally for deep focus, relaxation, and sleep. (Keywords: white noise generator, pink noise, brown noise, ambient sound)
- [Metronome & Tap Tempo BPM](https://4pm.jp/metronome/): Accurate musical metronome with customizable beats and time signatures, plus intuitive tap-tempo calculator. (Keywords: metronome, tap tempo, bpm calculator, music practice)
- [Pitch Pipe & Tone Generator](https://4pm.jp/pitch/): Precision tone generator playing A4 (440Hz / 442Hz) tuning notes, musical scales, and custom frequencies. (Keywords: pitch pipe, tone generator, 440hz tuner, frequency generator)
- [Web Synthesizer & Virtual Piano Keyboard](https://4pm.jp/synth/): Playable browser polyphonic synthesizer with virtual piano keys, multiple waveforms, ADSR envelope shaping, and stereo delay. (Keywords: web synth, virtual piano keyboard, synthesizer online, polyphonic synth)
- [Instant Sound Effects Board (Soundboard)](https://4pm.jp/soundboard/): One-click soundboard for events and streams featuring synthesized quiz bells, buzzers, drum rolls, applause, and fanfares. (Keywords: soundboard, sound effects, quiz buzzer, drum roll sound)
- [Browser Audio Cutter & Waveform Trimmer](https://4pm.jp/audio-trim/): Cut and trim audio clips with visual waveform inspection. Fast, secure, and 100% client-side with instant WAV export. (Keywords: audio cutter, audio trimmer, mp3 cutter online, cut audio)
- [Voice Recorder & Reverse Audio Player](https://4pm.jp/audio-rec/): Record microphone audio directly in your browser. Play backwards, adjust speed/pitch, inspect waveforms, and download WAV recordings. (Keywords: voice recorder, reverse audio, mic recorder, audio reverse player)
- [16-Step Beat Sequencer & Drum Machine](https://4pm.jp/drum/): Interactive 16-step grid drum sequencer to compose drum beats and rhythms with kick, snare, hi-hat, and claps in real time. (Keywords: drum machine, beat sequencer, step sequencer, drum pattern)
- [Mini DAW & Piano Roll Music Maker](https://4pm.jp/daw/): Create melodies and multi-track songs with an intuitive browser piano roll. Features lead synthesizer, bassline, and drum beats with live Web Audio synthesis. (Keywords: mini daw, piano roll, music maker, browser daw)

### Humor, Fun & Novelty (ジョーク・ネタ)
- [Boss Key & Fake Screen Simulator](https://4pm.jp/boss/): Instant boss-key simulator switching to fullscreen fake VS Code, Excel, Windows Update, or BSOD with a single keypress or click. (Keywords: boss key, fake screen, fake update, bsod generator)
- [Ojisan Message Generator](https://4pm.jp/ojisan/): Generate hilarious Japanese 'Ojisan' (middle-aged man) style text messages filled with excessive emojis, quirky greetings, and awkward punctuation. (Keywords: ojisan generator, japanese text meme, emoji generator, quirky message)
- [Clap Emoji Text Generator](https://4pm.jp/clap/): Insert clapping hand emojis 👏 between words or letters to make your statements dramatically emphasized and loud for social media. (Keywords: clap emoji generator, clapping text, meme text maker, emoji insert)
- [Upside Down & Reverse Text Generator](https://4pm.jp/flip/): Turn your text upside down (uʍop ǝpᴉsdn) or mirror backwards using Unicode character mapping for social profiles and memes. (Keywords: upside down text, flip text, reverse text, mirror text)
- [Gyaru Moji & Retro Japanese Text Converter](https://4pm.jp/gyaru/): Convert text into Japanese 'Gyaru Moji' - the nostalgic 2000s flip-phone retro texting slang style using complex glyph substitutions. (Keywords: gyaru moji, retro japanese text, flip phone slang, 2000s text converter)
- [Matrix Digital Rain Fullscreen Simulator](https://4pm.jp/matrix/): Classic Matrix movie digital rain effect in fullscreen with green falling glyphs, speed controls, custom characters, and ambient vibes. (Keywords: matrix rain, digital rain, hacker screen, matrix effect)
- [Shaking Text & Rage CSS Generator](https://4pm.jp/shaketext/): Generate violently vibrating and shaking text CSS keyframe animations and humorous trembling text memes. (Keywords: shaking text, vibrating text, rage text, trembling text)
- [Fake Tweet & SNS Post Mockup Generator](https://4pm.jp/fake-tweet/): Generate realistic fake X (Twitter) post screenshot images for memes, presentations, and mockups completely client-side. (Keywords: fake tweet generator, mockup tweet, fake post generator, twitter screenshot)
- [Bad UI Museum & User Experience Parody](https://4pm.jp/bad-ui/): Interactive gallery of hilariously terrible user interfaces: runaway submit buttons, roulette volume sliders, and impossible inputs. (Keywords: bad ui, worst ui design, user experience satire, funny ui)
- [Fart Soundboard & Whoopee Cushion](https://4pm.jp/fart/): Customizable fart sound generator and timed whoopee cushion prank running completely offline with synthesized audio. (Keywords: fart soundboard, whoopee cushion, fart machine, sound prank)
- [Japanese Industry Slang & Character Voice Converter](https://4pm.jp/yoda/): Convert standard text into classic 90s Japanese inverted industry slang (Togo) or anime character speech styles. (Keywords: industry slang, japanese backwards slang, anime voice converter, fun text converter)
- [Hollywood Hacker Typer Simulator](https://4pm.jp/hacker-typer/): Type furiously on your keyboard to instantly produce complex kernel code and Hollywood-style hacking popups. (Keywords: hacker typer, hollywood hacker, fake hacking, code tycoon)
- [Tech Support Scam & Fake Virus Alert Simulator](https://4pm.jp/scam-alert/): Experience realistic fake tech support virus alerts safely in your browser. Learn how scam sites induce panic and how to dismiss them safely. (Keywords: tech support scam, fake virus alert, scam simulator, fake malware warning)

### File Utilities & Storage (ファイル操作)
- [Client-Side ZIP Creator & Extractor](https://4pm.jp/zip/): Create ZIP archives from multiple files or unzip and preview files locally without uploading anything to a server. (Keywords: zip extractor, create zip online, unzip browser, zip archive maker)
- [File Integrity Hash Checker (SHA-256 / MD5)](https://4pm.jp/hash-file/): Calculate cryptographic hash checksums (SHA-256, SHA-1, MD5) for large files locally to verify download integrity. (Keywords: file hash calculator, sha256 checksum, verify file integrity, md5 file check)
- [File Splitter & Merger Utility](https://4pm.jp/file-split/): Split large files into smaller byte chunks for email or cloud upload limits, and merge split files back into original files locally. (Keywords: file splitter, file merger, split large files, join split files)
- [Text Encoding Fixer & Converter (Shift-JIS / UTF-8)](https://4pm.jp/text-encoding/): Fix garbled Japanese text mojibake and convert text files between Shift-JIS, EUC-JP, and UTF-8 encoding locally. (Keywords: mojibake fixer, text encoding converter, shift-jis to utf-8, japanese encoding)
- [File Header Inspector & MIME Type Detector](https://4pm.jp/file-info/): Inspect file magic bytes to reveal the true underlying file format, MIME type, and binary header structure. (Keywords: file inspector, magic bytes, mime detector, header analyzer)
- [Binary File Hex Viewer & Inspector](https://4pm.jp/bin-hex/): Inspect arbitrary files in a classic side-by-side hex dump viewer with hex search, ASCII decoding, and offset navigation. (Keywords: hex viewer, binary inspector, hex dump, byte viewer)
- [File Metadata Inspector, Editor & Cleaner](https://4pm.jp/file-meta/): Inspect, edit, and wipe sensitive metadata from images (Exif) and audio files locally. Remove GPS coordinates and private tags before sharing. (Keywords: metadata editor, exif remover, strip metadata, file privacy)

### Mini Games & Puzzles (ミニゲーム)
- [Classic Minesweeper Game](https://4pm.jp/minesweeper/): The classic Windows Minesweeper puzzle game with Beginner, Intermediate, and Expert difficulties, flag markers, and timer. (Keywords: minesweeper, minesweeper online, classic minesweeper, bomb puzzle)
- [Classic Snake Arcade Game](https://4pm.jp/snake/): Classic retro arcade Snake game with smooth grid movement, food pickups, score tracking, and keyboard or touch controls. (Keywords: snake game, classic snake, arcade snake, retro snake)
- [Sudoku Puzzle Generator & Auto-Solver](https://4pm.jp/sudoku/): Generate unlimited Sudoku puzzles across Easy, Medium, and Hard, with pencil notes, mistake checking, and instant solver. (Keywords: sudoku, sudoku generator, sudoku solver, number puzzle)
- [Memory Card Match Puzzle Game](https://4pm.jp/memory/): Test and sharpen your memory by finding matching pairs of emoji cards with customizable grid sizes, turn counters, and timer. (Keywords: memory match, card memory game, concentration game, pair matching)
- [Lights Out Grid Puzzle Game](https://4pm.jp/lights-out/): Classic electronic grid puzzle where tapping a cell toggles itself and adjacent neighbors. Turn off all lights to win! (Keywords: lights out, grid puzzle, logic puzzle game, toggle lights)
- [Classic 15-Puzzle Sliding Block Game](https://4pm.jp/sliding/): The classic 15 sliding tile puzzle game. Slide numbered tiles into the empty space to arrange them in numerical order. (Keywords: 15 puzzle, sliding puzzle, 15 tile game, number slider)
- [Tower of Hanoi Puzzle & Recursive Solver](https://4pm.jp/hanoi/): Play the classic Tower of Hanoi puzzle and watch the recursive divide-and-conquer solver animate optimal moves in real time. (Keywords: tower of hanoi, hanoi solver, recursive algorithm, hanoi puzzle)
- [Classic Klondike Solitaire Card Game](https://4pm.jp/solitaire/): The classic Windows Klondike Solitaire card game. Features 1-card and 3-card draw, move counter, timer, and auto-complete. (Keywords: solitaire, klondike solitaire, classic solitaire, card game)
- [Retro Space Arcade Shooter Game](https://4pm.jp/shooter/): Classic retro arcade space shooter. Blast alien invaders with lasers, collect power-ups, defeat bosses, and set high scores. (Keywords: space shooter, retro shooter, arcade game, space invaders)
- [Classic Breakout & Block Breaker Game](https://4pm.jp/breakout/): Classic paddle and ball brick breaker game with multi-ball powerups, score streaks, and satisfying retro sound effects. (Keywords: breakout, brick breaker, arkanoid, block breaker)
- [Nonogram Picture Logic Puzzle (Picross)](https://4pm.jp/nonogram/): Solve picture logic nonogram puzzles by filling grid cells according to row and column number clues. Multiple grid sizes with cross marks. (Keywords: nonogram, picross, picture logic, griddlers)