ToolBox

All Tools

Every tool works offline in your browser — nothing is ever uploaded.

70 tools

Base64 Encoder & Decoder

Free online Base64 encoder and decoder with full UTF-8 support. Convert text to Base64 or decode Base64 back to plain text instantly.

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URL Encoder & Decoder

Free online URL encoder and decoder. Percent-encode query parameters or encode complete URLs while preserving their structure.

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Word Counter

Count words, characters, sentences and paragraphs in real time as you type. CJK-aware word counting and a reading-time estimate included.

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Text Case Converter

Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case and kebab-case in one click.

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Regex Tester

Test JavaScript regular expressions live. See every match highlighted with capture groups, match indexes and instant syntax errors.

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Markdown Editor

Write Markdown with a live sandboxed preview, then export clean HTML or the .md source.

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Mojibake Fixer

Fix garbled Chinese text caused by wrong encodings. Tries UTF-8, GBK, Big5 and Latin-1 round-trip combinations.

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Pinyin & Zhuyin Converter

Convert Chinese text to Pinyin (with or without tones) and Zhuyin/Bopomofo. Polyphonic characters handled by context.

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Lorem Ipsum Generator

Generate Lorem Ipsum paragraphs, sentences or words for design mockups — with or without the classic opening. Free and instant.

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Markdown to PDF

Convert Markdown to a print-styled document and save it as PDF through the browser print dialog — selectable text, crisp fonts.

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Text Diff Checker

Compare two texts line by line and see additions and deletions highlighted, with add/remove counters. Ignore case or edge whitespace when comparing.

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Chinese Converter

Convert Chinese text between Simplified and Traditional, including Taiwan and Hong Kong variants with their local vocabulary (软件 → 軟體).

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Text Line Tools

Chain operations on a list of lines: dedupe, sort (A–Z, by length, by number), drop blank lines, trim, renumber, reverse, shuffle and more — with live line / unique / word counts and one-step undo.

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Chinese Grid Paper & English Lines

Generate printable practice paper: 米字格, 田字格, plain squares, or English four-line and single-line ruled sheets. Set columns, cell size or line spacing and pages, print light-grey model text for tracing in any calligraphy font, then download a vector PDF.

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JSON Formatter

Format, validate and minify JSON online. Pretty-print with 2 or 4 spaces, get precise error positions, and copy or download the result.

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UUID Generator

Generate random UUID v4 and time-ordered UUID v7 identifiers in bulk, using the browser cryptographic random API. Copy one or all with a click.

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Unix Timestamp Converter

Convert Unix timestamps to readable dates and back. Shows local time, UTC and ISO 8601, handles both seconds and milliseconds, with a live current-time display.

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JWT Decoder

Decode JWT header and payload into readable JSON, with expiry and issue dates converted to human-readable form.

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Cron Expression Parser

Parse and generate cron expressions online for Linux crontab, Spring @Scheduled and Quartz. Per-field breakdown, plain-language schedule and next run times.

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Number Base Converter

Convert numbers between binary, octal, decimal, hex and any base from 2 to 36 instantly. Live results as you type.

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User-Agent Parser

Parse any User-Agent string into browser, engine, OS, device and CPU details. Your own UA is pre-filled.

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JSON to Entity Classes

Generate typed entity classes from JSON for TypeScript, Java, Go, C#, Python, Kotlin and Swift. Nested objects become separate classes.

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Excel & CSV Converter

Convert .xlsx files to CSV (per sheet) and CSV text or files back to Excel workbooks. Parsing via SheetJS.

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Large Log Viewer

Open huge log files (hundreds of MB) streamed in the browser, with instant level counts and keyword search.

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SQL Playground

Run real SQLite queries in the browser: a demo database to explore, sample queries, and instant result tables. Powered by sql.js WASM.

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XML Formatter

Format, validate and minify XML with a collapsible tree: pretty-print with 2/4 spaces or tabs, jump to syntax errors by line and column, copy or download the result.

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YAML Formatter

Format and validate YAML (.yml) with a collapsible tree: normalize indentation, jump to syntax errors by line and column, multi-document files supported, plus a compact flow-style output.

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CSS Formatter & Minifier

Beautify or minify a stylesheet with a quote- and comment-aware parser: calc(), content strings, data URIs and selector whitespace stay intact. Shows byte savings and a semantic consistency check.

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Hash Generator

Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text instantly via the Web Crypto API.

Security & Encoding

Password Generator

Generate cryptographically random strong passwords. Choose length, character sets and exclude look-alike characters.

Security & Encoding

Hash Collision & Cracking Simulator

Interactive demos of the birthday attack and brute-force preimage search on truncated hashes. Educational and hands-on.

Security & Encoding

TOTP Code Generator

Generate time-based one-time passwords (TOTP) from a Base32 secret or an otpauth:// URI: 6/8 digits, 30/60s periods, SHA-1/256/512, with the current code, its remaining seconds and the next code.

Security & Encoding

File Checksum (MD5 / SHA-256)

Drop files to compute MD5, SHA-1 and SHA-256 in one pass, then paste the published checksum to confirm a download is intact and untampered.

Security & Encoding

Image Compressor

Compress JPG, PNG and WebP images with a quality slider and optional resizing. No size limits, no queues.

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QR Code Generator

Generate QR codes for URLs, text or any content. Customize size, colors and error correction, then download a crisp PNG. Static codes never expire.

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Signature Pad

Draw a smooth handwritten signature with mouse, touch or stylus. Adjustable pen, undo, and transparent-background PNG export.

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Image Watermark & Blind Watermark

Add visible text watermarks (position/tile/opacity) and embed invisible LSB blind watermarks that can be extracted later.

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Image Grid Cutter

Split an image into a 3×3 grid (or custom rows × columns) for social media feeds. Preview tiles and download them all.

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Long Image Stitcher

Stitch multiple screenshots into one long image vertically or horizontally, with gap and background options.

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Photo Collage Maker

Combine photos into one image on a three-pane workspace: layouts on the left, the collage canvas in the middle (upload per cell), canvas and export settings on the right. 35 layouts, drag a photo onto another cell to swap, Alt-drag to reposition, wheel zoom, arrow-key nudges, resizable dividers, background image/color, export PNG/JPEG up to 3072 px or copy to clipboard.

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EXIF & GPS Viewer

Extract EXIF metadata and GPS coordinates from photos: camera, lens, exposure settings and map links.

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Favicon Generator

Turn any image into a complete favicon set: 16-256px PNGs, a multi-resolution .ico file, Apple touch icon and ready-to-paste HTML.

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SVG / Text to Image

Rasterize SVG to PNG at any scale, or render long text into a styled PNG image. Perfect for code screenshots and share cards.

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Video to GIF

Convert a clip of MP4/WebM video to an animated GIF: pick start, duration, FPS and size, then download.

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Image Color 3D Visualizer

See the colors of any image as an interactive 3D point cloud in RGB space. Drag to rotate, scroll to zoom. Rendered with Three.js.

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QR Code Reader

Read the contents of a QR code from an image: upload, drop or paste a screenshot and the decoded text appears with a link shortcut for URLs. Works with Wi-Fi, vCard and JSON payloads too.

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Image Cropper

Crop an image with a draggable, resizable selection and ratio presets (1:1, 4:3, 3:4, 16:9, 9:16, free). Live output preview with exact pixel dimensions, export as PNG or JPEG.

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Images to PDF

Drop a batch of images and get a single PDF: pages follow your order, sizing can track each image or use A4 portrait / landscape with margins, and WebP or GIF input is converted on the fly.

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Color Converter

Convert colors between HEX, RGB, HSL and HSV with a live preview. Pick a color or paste any CSS color value and copy the format you need.

Web & CSS

Font Size & Unit Converter

Convert font sizes between px, pt, em, rem and %, with a Chinese type-size reference table (初号 to 八号). Live results.

Web & CSS

CSS Gradient Generator

Build linear or radial CSS gradients visually: drag angle and colour stops, use presets, then copy the CSS or download the gradient as a PNG.

Web & CSS

Color Contrast Checker

Check the WCAG contrast ratio between text and background colours, with AA/AAA verdicts for normal and large text plus a live preview.

Web & CSS

Subnet Calculator

Calculate network and broadcast address, subnet and wildcard masks, usable host range and address type from an IPv4 CIDR, and split the network into equal subnets.

Web & CSS

Color Palette Generator

Pick a base colour and get complement, split-complement, triadic, tetradic, analogous and monochromatic schemes plus an 11-step tint–shade ramp, with CSS variables and JSON export.

Web & CSS

Stopwatch & World Clock

Precise online stopwatch with lap times, plus a live world clock: analog dials for major cities with digital readouts and UTC offsets below.

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Keyboard Tester

Test every key on your keyboard online: see key codes, modifier states and a rolling press log. Nothing to install.

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Mouse Tester

Test mouse buttons, wheel and tracking online. Live coordinates, click counters per button and a movement trail on canvas.

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Screen Test

Fullscreen pure-color tests to find dead pixels and check uniformity, plus screen info: resolution, pixel ratio and color depth.

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BMI & BMR Calculator

Calculate BMI (WHO/CN categories), body fat percentage (U.S. Navy tape method) and basal metabolic rate (Mifflin-St Jeor) with daily calorie needs.

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White Noise & Tone Generator

Play white, pink or brown noise and pure-tone sound waves for sleep, focus or tinnitus relief. Generated live by Web Audio.

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Mortgage Calculator

Free mortgage calculator for commercial, housing-fund and mixed loans: monthly payment, total interest and per-part breakdown. Fixed or decreasing repayment, common-rate presets, works by loan amount or home price.

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Jigsaw Puzzle Generator

Turn any image into a playable jigsaw puzzle (3×3 to 5×5) with a timer and move counter. Click two tiles to swap them.

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Virtual Piano & MIDI

Play a two-octave piano with your computer keys, mouse or a real MIDI keyboard. Web Audio synthesis with selectable waveforms.

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2D Floor Plan Editor

Draw a floor plan: grid-snapped walls with auto dimensions, doors, windows and PNG export.

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Countdown Timers

Add as many countdowns as you need — each with its own name, duration and progress ring. Presets like 5 or 25 minutes add in one click, timers run independently, and a triple beep plays when one reaches zero.

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Unit Converter

Convert between units of length, weight, area, volume, temperature, speed, data storage and time — with an instant table of the value in every unit of the category.

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PDF Toolbox

Merge several PDFs in any order, extract a page range into a new file, delete pages, or rotate every page by 90/180/270 — files never leave the page.

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Date Calculator

Compute the interval between two dates (years/months/days, total days, weekdays), add or subtract days, weeks, months or years — with an optional business-day mode — and turn a birthday into an age plus a countdown.

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Camera & Mic Test

Start a local preview to confirm your camera and microphone work: live resolution and frame rate, a mic level meter that warns when nothing is picked up, device switching and a PNG snapshot.

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Screen Recorder

Record a screen, application window or browser tab with optional system / tab audio and microphone mixing, pause and resume while recording, then preview and download the result as a WebM video.

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