All Tools
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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.
URL Encoder & Decoder
Free online URL encoder and decoder. Percent-encode query parameters or encode complete URLs while preserving their structure.
Word Counter
Count words, characters, sentences and paragraphs in real time as you type. CJK-aware word counting and a reading-time estimate included.
Text Case Converter
Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case and kebab-case in one click.
Regex Tester
Test JavaScript regular expressions live. See every match highlighted with capture groups, match indexes and instant syntax errors.
Markdown Editor
Write Markdown with a live sandboxed preview, then export clean HTML or the .md source.
Mojibake Fixer
Fix garbled Chinese text caused by wrong encodings. Tries UTF-8, GBK, Big5 and Latin-1 round-trip combinations.
Pinyin & Zhuyin Converter
Convert Chinese text to Pinyin (with or without tones) and Zhuyin/Bopomofo. Polyphonic characters handled by context.
Lorem Ipsum Generator
Generate Lorem Ipsum paragraphs, sentences or words for design mockups — with or without the classic opening. Free and instant.
Markdown to PDF
Convert Markdown to a print-styled document and save it as PDF through the browser print dialog — selectable text, crisp fonts.
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.
Chinese Converter
Convert Chinese text between Simplified and Traditional, including Taiwan and Hong Kong variants with their local vocabulary (软件 → 軟體).
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.
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.
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.
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.
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.
JWT Decoder
Decode JWT header and payload into readable JSON, with expiry and issue dates converted to human-readable form.
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.
Number Base Converter
Convert numbers between binary, octal, decimal, hex and any base from 2 to 36 instantly. Live results as you type.
User-Agent Parser
Parse any User-Agent string into browser, engine, OS, device and CPU details. Your own UA is pre-filled.
JSON to Entity Classes
Generate typed entity classes from JSON for TypeScript, Java, Go, C#, Python, Kotlin and Swift. Nested objects become separate classes.
Excel & CSV Converter
Convert .xlsx files to CSV (per sheet) and CSV text or files back to Excel workbooks. Parsing via SheetJS.
Large Log Viewer
Open huge log files (hundreds of MB) streamed in the browser, with instant level counts and keyword search.
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.
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.
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.
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.
Hash Generator
Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text instantly via the Web Crypto API.
Password Generator
Generate cryptographically random strong passwords. Choose length, character sets and exclude look-alike characters.
Hash Collision & Cracking Simulator
Interactive demos of the birthday attack and brute-force preimage search on truncated hashes. Educational and hands-on.
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.
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.
Image Compressor
Compress JPG, PNG and WebP images with a quality slider and optional resizing. No size limits, no queues.
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.
Signature Pad
Draw a smooth handwritten signature with mouse, touch or stylus. Adjustable pen, undo, and transparent-background PNG export.
Image Watermark & Blind Watermark
Add visible text watermarks (position/tile/opacity) and embed invisible LSB blind watermarks that can be extracted later.
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.
Long Image Stitcher
Stitch multiple screenshots into one long image vertically or horizontally, with gap and background options.
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.
EXIF & GPS Viewer
Extract EXIF metadata and GPS coordinates from photos: camera, lens, exposure settings and map links.
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.
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.
Video to GIF
Convert a clip of MP4/WebM video to an animated GIF: pick start, duration, FPS and size, then download.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Keyboard Tester
Test every key on your keyboard online: see key codes, modifier states and a rolling press log. Nothing to install.
Mouse Tester
Test mouse buttons, wheel and tracking online. Live coordinates, click counters per button and a movement trail on canvas.
Screen Test
Fullscreen pure-color tests to find dead pixels and check uniformity, plus screen info: resolution, pixel ratio and color depth.
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.
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.
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.
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.
Virtual Piano & MIDI
Play a two-octave piano with your computer keys, mouse or a real MIDI keyboard. Web Audio synthesis with selectable waveforms.
2D Floor Plan Editor
Draw a floor plan: grid-snapped walls with auto dimensions, doors, windows and PNG export.
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.
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.
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.
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.
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.
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.