Keep Your Input on Your Device.Privacy-Focused Utilities

Counts the number of characters in the input text and calculates the reading time in real time according to the speaking speed (normal, rapid, etc.).

There is no need to register as a member, and you can generate and download PDF-format invoices and estimates from input data only on your browser.

Calculates the monthly repayment amount, total repayment amount, and total interest amount from the loan amount, interest rate, and period, and displays a detailed repayment plan table and cumulative repayment amount chart.

You can calculate the expected future asset amount from the initial investment amount, monthly savings amount, yield, and number of years, and visually compare the difference between compound interest and simple interest.

Automatically calculates overtime pay (overtime, late night, holiday work) based on the Labor Standards Act based on basic wage (or basic hourly wage) and working hours.

Dynamically counts the actual number of business days excluding Saturdays, Sundays, holidays (Japanese national holidays and substitute holidays) and arbitrary holidays from the start date and end date.

Dynamically obtain the latest exchange rates for 6 major currencies (USD, EUR, JPY, GBP, CNY, AUD) online and convert amounts in both directions.

Calculate food and drink costs for multiple people by dividing them evenly or by group (more positions, fewer late arrivals, etc.) and rounding off the fractions.

Automatically calculates depreciation expense and unamortized balance by year using the straight-line method or declining-balance method based on a corporation's asset purchase cost and legal useful life.

We calculate the return on investment (ROI), investment payback period, net present value (NPV), and internal rate of return (IRR) from the initial investment amount and annual income.

Automatically calculates retirement income deduction amount, income tax/resident tax, and net take-home pay based on the amount of retirement allowance (retirement allowance) and years of service.

Instantly perform and compare ratio calculations that are easily confused in daily life and business, such as "What is Y% of X?" and "What percentage of Y is X?"

We accurately calculate the basic hourly wage (hourly rate), which is the basis of legal overtime pay, from monthly salary, daily wage, total annual working hours, etc.

Based on historical Consumer Price Index (CPI) data for Japan and other major countries, we will calculate how much 10,000 yen in the past is equivalent to today.

Simply enter item names, prices, etc. roughly in Markdown format, and the invoice will be automatically formatted into a beautiful and professionally designed invoice, which can then be printed as a PDF.

Automatically calculate one unknown element among cost price, sales price, discount rate, gross profit rate, and profit amount from slide bar operations of other elements.

Create a 200x200px transparent PNG stamp with up to four characters in round, vertical oval, or square shapes. Customize your stamp using available device fonts while adjusting colors, borders, and weathering effects.

Enter the transaction date, time, quantity, and price of virtual currency or tokens, and calculate simple annual profit and loss and taxes (miscellaneous income) using the moving average method or total average method.

The health of your business is simulated and displayed in graphs based on customer lifetime value (LTV), cost per customer acquisition (CAC), churn rate, and average cost per customer.

The number of days and expiration date (2-year expiry rule) of paid vacation granted based on the Labor Standards Act is automatically calculated from the scheduled number of working days per week and date of employment.

We will build a CSV for bulk schedule registration that can be directly imported into Google Calendar or Outlook from the specified date range, excluded days of the week, and specific holiday information.

Simulates the round-trip commission cost and loss cut line from the spread (coins/pips), trading volume, leverage, and required margin for trading in FX, etc.

Visualize the long-term growth difference between compound interest (interest of reinvestment) and simple interest (withdrawal of interest) when investing a fixed amount using a color-coded SVG line graph.

List the various monthly and annual subscription services you have registered, and visualize and export the total expenditure and ratio on a monthly and daily basis.

Based on the size and weight of the package, we compare the shipping standards of Yamato Transport, Yu-Pack, etc., and create a 3D drawing of the optimal box size and arrangement for the cheapest price.

Merge multiple PDF documents or extract specific page ranges directly within your browser. All operations run locally using your device resources, with no server uploads required for supported unencrypted PDFs.

Using ONNX Runtime Web, automatically crop the background of people and products in images on the browser.

Compress JPEG, PNG, WebP, and HEIC/HEIF images and export them as JPEG, PNG, or WebP in your browser. Adjust target file size and maximum dimensions with client-side batch processing.

Resize browser-supported images by percentage or custom dimensions and export JPEG, PNG, or WebP.

No software installation required, record browser tabs and entire desktop screen and save locally.

Erase unwanted objects with a brush mask using Canvas patch-matching and neighborhood color averaging without AI models. Best for small areas and simple backgrounds, with PNG export.

Minimize file size by removing unnecessary metadata, empty elements, and editor-specific tags such as Illustrator and Inkscape from your SVG code.

Decode audio files (MP3, WAV, M4A, OGG) on your browser, convert them all at once to WAV or WebM format, and save them.

Completely removes personal information and metadata contained in images (JPEG, PNG) such as GPS location information, photography equipment, and date and time of photography.

Create an original animated GIF by uploading multiple image files and setting the frame order and playback speed (FPS).

Supports side-by-side grid playback for multiple formats, as well as sequential chain merging for GIFs. Files are processed locally in your browser.

You can decode the audio file, display the waveform, and intuitively specify the cutting range using the slider and save the cut.

Cut out an arbitrary range from a video such as MP4 and save it as a flip animation GIF or lightweight video file using Canvas drawing.

Standard browser voice preview may use external processing; this tool cannot export the standard voice. A separate synthetic robot voice can be saved as WAV on successful decode, or otherwise in the actual recorded WebM/MP4-family format.

Generates a high-quality QR code from any text or URL, and supports changing the color scheme and embedding a custom logo image in the center.

Read and analyze QR codes at high speed by loading image files or real-time scanning with a PC or smartphone camera.

Upload an image and get the color code (HEX/RGB/HSL) with a single click while viewing the pixel-by-pixel magnifying glass preview.

Freely create drawings and handwritten notes on your browser, and save and download them as PNG or JPEG images.

Blur or mosaic (pixelize) any part of the uploaded image by hand-drawing with a brush or using the rectangular selection tool.

Generates major one-dimensional barcodes such as JAN code (EAN-13/8), CODE39, ITF, Codabar, etc. on Canvas from input numbers with high precision.

Convert HEIC and HEIF photos to JPEG or PNG in your browser (up to 30 files, max 30MiB each) with adjustable quality. Decoding depends on device resources with no unlimited conversion guarantee.

Completely converts Excel file (.xlsx/.xls) sheet data and CSV files into each other on a local browser, taking into account the state of formulas and character encoding.

Render a vector image (SVG) at high resolution and convert it to a transparent PNG, or trace a PNG image (run-length path) and convert it to an editable SVG.

You can adjust and save the playback speed (tempo) and pitch/key of audio data (MP3, WAV, M4A, etc.) independently on the browser.

Extract text from images directly in your browser using client-side OCR. Character recognition processes locally once required language data and engine assets are downloaded.

Encrypt (protect) and restrict viewing of PDF files with a password, or remove (decrypt) the password and convert to a plain PDF without a password.

You can view, edit, and delete Exif metadata such as the shooting date and time, camera device information, and GPS location information included in images (JPEG) directly on your browser.

Edit and preview SVG path data (d attribute) intuitively using drag-and-droppable anchor points and control handles.

Merges multiple icons and small images into one combined image (sprite image), and automatically outputs the display position specification code (background-position) using CSS.

Generate dynamic frequency spectrum and waveform animation videos from audio files. You can record locally and download it as a WebM video.

We beautifully synthesize screenshot images from smartphones and PCs into the frames of the latest iPhones, MacBooks, and monitors to generate images for PR materials and materials.

Compress multiple files into one ZIP file, or expand (unzip) an existing ZIP file on your browser.

Load a large number of file names by copying and pasting or dragging and dropping, and simulate rules such as string replacement, regular expressions, and sequential numbering in real time.

Extract an arbitrary time range from a video (MP4/WebM), sample frames, and convert them to high-quality animated GIF, or vice versa.

Easily crop images to your preferred ratio (1:1, 16:9, 4:3, free) by dragging. It also supports circular cutouts for avatars.

Swaps the left and right channels of the audio file, mixes it to monaural, extracts L/R individual channels, and adjusts the localization panning.

Format, validate, and minify JSON strings directly in your browser. Checks syntax and reports parse errors while preserving number formatting and key order.

Converts character strings and binary data to hexadecimal, binary, Base64, URL encoding, etc. in real time.

Input the source code, generate and export images with beautiful gradient backgrounds and editor-like decorations.

Images will be cropped and resized according to the recommended size of each SNS platform (X, Instagram, YouTube, etc.).

Generates Lorem Ipsum text for layout confirmation and random text in the style of classical Japanese literature (such as Aozora Bunko).

Remove unnecessary spaces, line breaks, and comments from HTML, CSS, and JavaScript code to minimize file size.

Decode and inspect JWT headers and payloads directly in your browser. Displays Base64URL-decoded JSON structure and expiration status without performing cryptographic signature verification.

Test JavaScript regular expressions directly in your browser against custom text. View match highlights, capture groups, and index positions with support for standard flags.

Breaks down complex URLs into protocols, hosts, paths, and query parameters, then edits and reconstructs the parameters in a grid format.

Visually adjust the shadow direction, blur, diffusion, color (RGBA), opacity, and inner shadow (Inset), and output CSS code.

You can create linear and radial gradations and intuitively add, move, and delete color stops.

Special characters (<, >, &, \

This is an editor that allows you to display and check text entered in Markdown notation alongside an HTML preview in real time.

Convert a single YAML document to JSON or convert JSON to YAML locally. Nested objects and arrays are supported, with explicit input and output limits.

Converts CSV data from spreadsheets and databases into JSON or XML formats that are easy to handle programmatically.

It formats difficult-to-read SQL statements beautifully and easily by capitalizing reserved words, adding appropriate line breaks, and inserting indents.

Assemble an HTTP request (method, content-type, various authentications, etc.) and visualize the generated headers and expected responses.

Performs indentation formatting of XML text and syntax checking (identifying error lines) such as missing closing tags on the browser.

Automatically generate a specified number (up to 500) of random and unique IDs (UUID v4 or v1) at once.

Automatically converts text and HTML source code to each other, such as converting text line breaks to <p> tags and URLs to <a> links.

Just select the action you want to perform, such as branching or undoing a commit, from the menu and the correct Git command will be automatically generated.

We will construct and explain the correct cron execution description (* * * * *) by specifying the minute, hour, day, month, and day of the week from intuitive selection boxes.

Define the number of rows and columns and gap width in the on-screen grid, and generate CSS Grid layout code interactively.

Contrast ratio is calculated from text color and background color, and compliance with WCAG 2.1 standards (AA/AAA) is determined in real time.

Automatically calculates network address, host range, and broadcast address from IP address and subnet mask.

Automatically converts regular HTML code into JSX code for React components (className replacement for class, htmlFor replacement for for, inline style objectification, self-closing tag completion, etc.).

Easily convert basic shell commands and script structures (file moves, string searches, environment variable settings, etc.) between Bash and PowerShell, and display a syntax comparison guide.

Use the border property trick to specify the size, orientation, and color of triangles (up, down, for callouts, etc.) that can be drawn using only CSS, and get CSS and Tailwind code.

Converts between the three main configuration file formats: JSON, YAML, and TOML with syntax validation.

Load your font file (.ttf / .otf / .woff / .woff2) into the browser, perform a display test, and generate Base64 code for CSS embedding.

Automatically builds definition files for SSH connection settings (~/.ssh/config) and Git global environment settings (~/.gitconfig) using form input.

Based on the base color, a beautiful palette is automatically calculated based on color harmony theory (complementary colors, analogous colors, triads, divisive complementary colors, tetrads, monochromes, etc.).

Generate the virtual host settings (nginx.conf) for the web server Nginx. Supports cache, Gzip, SSL, and reverse proxy.

Select the target environment such as Node.js, Python, Go, macOS, Windows, VSCode, IntelliJ, Unity, etc. and create a clean .gitignore file.

Visually design the docker-compose.yml file that defines a multi-container configuration using form operations.

Specify the position, size, transparency, and rotation along the timeline, and output the @keyframes CSS code while previewing the animation of the change.

It analyzes the syntax of the input regular expression and draws state transitions (state machines) and tree structures on the canvas to visualize "which parts are functioning and how."

It reads JSON data such as API responses and automatically constructs TypeScript interface definitions, including nested objects.

A comprehensive reference catalog of HTTP status codes compliant with RFC 9110. You can instantly search for Japanese explanations, detailed meanings, corresponding RFC sections, and mock examples of common API responses.

In addition to aligning messy GraphQL queries and schema (SDL) indentations, neatly formatting, syntax checking, and compressing (Minify), you can easily design schemas using GUI operations.

Create a table using a GUI operation such as a spreadsheet or Excel, and automatically output Markdown table text with neatly aligned widths.

Generates a CSS clamp() expression that smoothly scales the font size according to the minimum and maximum screen width.

Automatically converts the terminal's curl command into a request code using JavaScript's standard Fetch API or Axios.

You can generate and download color badges (Shields.io style) for flat and beautiful parameter display in SVG format, perfect for GitHub READMEs, etc.

Specify a JSONPath expression or JQ-style filter from a large amount of JSON data to instantly extract specific data nodes and display them in a tree.

Mutually converts and restores text characters to various Unicode escape codes (\\uXXXX, \\u{XXXX}, HTML numeric character reference, %uXXXX).

This is a generator that can automatically create and output beautiful pixel art drawn using only one HTML element and the box-shadow property.

This is a productivity tool that alternates between 25 minutes of concentration time and 5 minutes of break time, and notifies you with a sound or desktop notification when the work is completed.

The entered name list will be shuffled, randomly divided into teams, and representatives will be selected using a roulette wheel.

Transcribes live audio from your microphone and appends finalized speech recognition results to an editable text area. Depending on your browser, audio may be sent to an external speech recognition service.

Create an original vocabulary book and perform memorization efficiently based on the timing of the forgetting curve (spaced repetition).

This is a rhythm/performance tool that plays a click sound at a precise tempo according to the specified BPM and time signature, and makes the screen blink.

This is a breathing method guidance tool that helps you meditate and relieve stress by following an animation that tells you when to breathe (inhale, hold, exhale).

Test your character input speed (WPM) and accuracy by accurately typing short English or Japanese Romaji texts within a time limit.

The surrounding volume (sound pressure level) from the microphone is collected in real time, and the simple decibel (dB) value of the entire environment is displayed on a meter.

Displays the entire screen in a single color (red, green, blue, white, black, etc.) and inspects the LCD monitor for missing dots, color unevenness, and light leakage.

Performs dice rolling, coin tossing, and generation of a random number list within a specified range with intuitive 3D-like animation.

A piano keyboard that runs on your browser. You can enjoy simple performances by selecting a sound wave waveform and assigning keys on your mouse or PC keyboard.

Randomly generate quizzes on addition, subtraction, multiplication, and division. It is optimized for print layout (A4), and you can also toggle display/hide of answers.

Enter the daily goals you want to make into a habit (exercise, study, etc.), check the calendar on the day you achieve them, and display a list of your continuation rates.

Display the current time in major world cities side by side in analog and digital format, and use the slider to compare time differences (meeting candidate times, etc.).

Based on height, weight, age, and activity intensity, obesity degree (BMI), basal metabolism (BMR), and total calorie expenditure (TDEE) are calculated and drawn on a visual meter.

You can create pixel art on a 16x16 or 32x32 grid, set layers and animation frames, and save it as a transparent PNG or GIF animation.

You can play the game by generating a random maze using an algorithm and manually aiming for the goal, or you can watch the automatic solving process of the search algorithm through animation.

While viewing public domain Western masterpieces in high quality, you can customize the frame style and exhibition room lighting, and extract the colors (HEX code) of each work.

You can create and save beautiful geometric art in real time by adjusting mathematical models such as fractals, chaotic orbits, and golden angle Fibonacci spirals.

This is a concentration BGM synthesis tool that allows you to blend white noise, pink noise, brown noise, and the sounds of rain, wind, and waves to your desired balance.

This is a tool that can measure lap times and split times infinitely in 1/1000 second units, graph average laps, highest/lowest laps, and export them as CSV files.

This is an educational illustrated book that visually displays detailed physical properties, electronic configuration (bohr model animation display), absorption and emission spectra, etc. by clicking on each element in the periodic table of elements.

View arrival local date and time along with time progression based on departure date and time, flight duration, and manual UTC offset or DST settings.

This is a 3D Rubik's Cube that uses CSS 3D Transforms and can be moved intuitively by dragging.

Play Reversi against AI across three difficulty levels, with relative evaluation heatmaps for candidate moves. You can also select hint depths of 1, 3, or 5 to analyze the board.

This is a tool that allows you to play Sudoku puzzles of different difficulty levels, or automatically answers input puzzles using a backtracking algorithm, and visualizes the search process with animation.

This is a portable sampler that allows you to record environmental sounds and voices from a microphone, and then assign them to a keyboard or drum pad to enjoy sampled performances.

A secure Kanban board task management tool that saves in LocalStorage, allowing you to move cards intuitively using drag and drop.

This is a tool that uses the Web Audio API to generate high-frequency sounds from 8kHz to 20kHz to easily measure and test ear age based on the hearing limit.

This is a classic brain training game (Simon) in which you memorize the pattern order of panels with lights and sounds, and correctly reproduce sequences that gradually become longer.

This is a tool that allows you to simulate Conway's Game of Life on your browser and observe the dynamic changes of cell birth and death.

This is a tool that allows you to play the classic 15 puzzles, or create a split puzzle from your own images, and enjoy the automatic shortest strategy animation using the A* algorithm.

It is a mind map editor that allows you to easily add nodes with key operations, organize the layout intuitively, and export it as SVG or PNG.

Manages your book collection directly in browser storage with manual entry support. Looking up an ISBN queries external services (openBD or Google Books), and loading cover images contacts their respective hosts.

Generate random passwords in your browser using the Web Crypto API. Customize character sets, exclude similar characters, and view theoretical entropy estimates.

Strongly encrypts (AES-GCM-256) or decrypts text on the browser using the specified password as a key.

Generates hash values ​​such as MD5, SHA-1, SHA-256, SHA-512, etc. from input text in real time.

Securely generate RSA key pairs (1024/2048/4096 bits) used for encryption and digital signatures on your browser.

Calculate the hash value (SHA-256/SHA-1/MD5) of the uploaded file and verify whether it matches the published value.

Secret text is embedded and extracted in the pixel data of an image (PNG) as extremely small noise that cannot be discerned by the human eye.

Generates and displays an OTP code for two-factor authentication that is updated every 30 seconds from a Google Authenticator-compatible secret key (Base32).

Encodes and decodes strings in real time to Base32 or Base58 format used by Bitcoin.

Converts regular Base64 strings and text to Base64 format that can be safely included in URL arguments (parameters).

Verifies whether the credit card number is compatible with the Luhn algorithm and automatically determines compatible card brands.

We measure the complexity and entropy of passwords and verify their resistance to cracking by offline and online attacks.

Visually experience the browser standard Web Crypto API and automatically generate encryption/signature JS code.

A detailed report on the current cryptographic connection method (TLS version, cipher suite, etc.) and communication protocol (HTTP/2/3).

Uses a DoH (DNS over HTTPS) server to resolve and display the DNS records (A, AAAA, MX, CNAME, TXT, NS, CAA) of the specified host.

Extracts GPS metadata from JPEG photos locally and sends coordinates to OpenStreetMap only when you explicitly open the map. Clearing the GPS IFD removes location tags, but does not anonymize all other EXIF metadata.

Analyzes URL structure locally using heuristics, with an optional opt-in HEAD request to inspect redirects. External reputation links pass either the full URL or domain depending on the service. Does not provide a definitive safety verdict.

We compare communication standards from SSL 2.0 to TLS 1.3 and determine vulnerability information and cipher suite strength.

Loads the SSL/TLS digital certificate (PEM/Base64 format) locally and decodes and analyzes the CN, organization, expiration date, serial, and hash value.

Attempts sequential HTTP fetch requests with a 1-second timeout. Cannot conclusively determine host reachability or TCP open/closed state because browser, CORS, and mixed-content restrictions affect results.

You can list, search, add, edit, and delete the browser's LocalStorage, SessionStorage, and Cookie values.

Queries external geolocation APIs (FreeIPAPI or ipapi.co) upon manual request and displays estimated regional coordinates on OpenStreetMap. Location results reflect network-level estimates rather than an individual's physical location.

Securely generate API keys, UUIDs, and private key tokens in bulk using a cryptographically secure random number generator (CSPRNG).

You can encrypt any local file using the AES-256 standard (.enc format) or decrypt it to its original file name just within your browser.

Visualizes the delivery route (Received) of raw email sources and the status of sending security authentication (SPF/DKIM/DMARC) in an easy-to-understand manner.

This is a simulator that allows you to switch the sandbox attribute (allow-scripts, etc.) of an iframe and verify browser security access restrictions.

You can mutually convert the character code of text and files to Shift_JIS, EUC-JP, UTF-8, etc., and decipher and repair garbled characters.

Extracts all strings that match regular expressions (emails, URLs, phone numbers, etc.) from text at once.

We aggregate and analyze the sequential appearance patterns (N-grams) of letters and words in sentences, as well as related words that tend to appear together with specific words (co-occurrence words).

In addition to the number of characters and lines, full-width/half-width discrimination, number of manuscript paper equivalents, etc. are counted in real time on the browser.

This is a local memo pad that automatically saves entered text so that data will not be lost even if you accidentally close the tab.

Compares two sentences and highlights added parts (green) and deleted parts (red) by line, word, or character.

Batch deletes duplicate lines from multiple lines of text and sorts and formats them in ascending order, descending order, length order, etc.

Convert text character formats at once, including uppercase/lowercase, camel, snake, full-width/half-width, hiragana/katakana, etc.

Converts a comma-separated string (CSV-like data) to a list of line breaks, or vice versa, by adding quotes.

Replace specific characters or strings in text at once using case sensitivity and regular expression patterns.

Preview the CSV data vertically (rows) and horizontally (columns) in table format, flip it, and re-output.

Bidirectionally converts JSON format object data to XML tag structure or XML to JSON format.

Remove or clean up extra spaces at the beginning and end of lines, consecutive spaces, and unnecessary line breaks in text at once.

Automatically generates English Lorem Ipsum and Japanese classical literature-style dummy sentences for web design comps and development verification.

Analyzes the User-Agent string sent by the browser and visualizes OS, browser, and device information.

This is a writing support tool that visualizes the length distribution of each paragraph/sentence of input text and the appearance ratio of punctuation marks (,.) in real time using a histogram.

Converts complex JSON data and CSV data with nested structures by mutually flattening the hierarchy.

We perform mutual conversion between Japanese (Japanese), alphanumeric characters (Roman) and Morse code, and perform pronunciation playback simulation using Web Audio API.

As a countermeasure against automatic email collection spambots, email addresses and phone numbers are converted into HTML entity references and obfuscated JavaScript code.

Sort the columns of the uploaded CSV file, rewrite the header, delete unnecessary columns, and extract row data conditionally.

Automatically sorts multiple lines of text or list data in alphabetical order, numerical order, character length order, random order, etc.

Verify whether the input JSON data meets the requirements defined by JSON Schema (type, required items, value range, etc.).

Converts Markdown (Markdown notation) documents and HTML code in both directions. Fully equipped with preview display function.

Smartly divides and slices long sentences according to the 140 character limit and API limit of X (formerly Twitter).

Detects and proofreads unnatural expressions in Japanese (double negatives, omitted words, redundant expressions, double words, etc.) and fluctuations in the spelling of okurikana.