View all · 223 online tools

Online JSON formatter with automatic indentation, syntax checking and minification. Tidy up JSON code, locate …

Online XML formatter with automatic indentation, syntax checking and minification. Tidy up XML code, locate fo…

Online SQL formatter with automatic indentation, syntax checking and minification. Tidy up SQL code, locate fo…

Online YAML formatter with automatic indentation, syntax checking and minification. Tidy up YAML code, locate …

Online HTML formatter with automatic indentation, syntax checking and minification. Tidy up HTML code, locate …

Online CSS formatter with automatic indentation, syntax checking and minification. Tidy up CSS code, locate fo…

Online JavaScript formatter with automatic indentation, syntax checking and minification. Tidy up JavaScript c…

Online Java formatter with automatic indentation, syntax checking and minification. Tidy up Java code, locate …

Online Python formatter with automatic indentation, syntax checking and minification. Tidy up Python code, loc…

Online Base64 / Base32 / Base16 Encoder with instant results and one-click copy. Handles UTF-8 text and Chines…

Online URL Encoder/Decoder with instant results and one-click copy. Handles UTF-8 text and Chinese characters;…

Online JSON Escape Tool with instant results and one-click copy. Handles UTF-8 text and Chinese characters; ev…

Online Unicode Converter with instant results and one-click copy. Handles UTF-8 text and Chinese characters; e…

Online HTML Entity Encoder with instant results and one-click copy. Handles UTF-8 text and Chinese characters;…

Convert text to its UTF-8 hex representation and back. Four separator styles (space, run-on, comma, 16 bytes p…

Turn text into 8-bit binary and back. Group every 8 bits, run them together, or group by four bytes with a con…

Translate between text and Morse code across A-Z, digits and common punctuation, with either . - or · − symbol…

Decode QR codes from uploaded, dragged or pasted images, entirely in your browser.

Online CSV to JSON converter with custom delimiters and header-row mapping. Turn tabular data into JSON quickl…

Online Excel to JSON converter supporting .xlsx and .xls with worksheet selection. Turn spreadsheet data into …

Pack multiple files into a ZIP archive with drag-and-drop support. Everything runs locally in your browser.

Upload a ZIP archive to preview and extract its files. Download individually or in bulk, all inside your brows…

Convert between JSON, YAML and XML in any of the six directions. The YAML side handles mappings, sequences, in…

Online JSON to XML converter with custom root element and indentation. Turn JSON data into well-formed XML in …

Online XML to JSON converter with configurable indentation. Convert XML data into formatted JSON in one click.…

Online CSV to SQL converter with custom table names, delimiters and quoting styles. Generate SQL INSERT statem…

Online Excel to SQL converter for .xlsx and .xls with worksheet selection. Generate SQL INSERT statements from…

Decode barcodes from images in the browser. Supports CODE128, EAN13, EAN8, UPC, CODE39 and more.

Batch rename files with prefixes, suffixes, numbering, find & replace, case conversion and extension changes. …

Test regular expressions with live matching and highlighted results. Supports common flags to help debug and v…

Compare two texts line by line with highlighted differences. Spot additions, deletions and edits quickly. Full…

Count characters, Chinese characters, English words, paragraphs and estimated reading time in real time. Fully…

Pull emails, URLs, phone numbers, ID numbers, dates, amounts, IP addresses, UUIDs, numbers and hashtags out of…

Convert between camelCase, snake_case, kebab-case, CONSTANT_CASE and more. Essential for renaming identifiers.…

Convert between Simplified and Traditional Chinese with common regional wording differences handled. Fully pro…

Two-way conversion between Markdown and HTML. Markdown to HTML handles headings, emphasis, strikethrough, code…

Online Markdown editor with live preview, syntax highlighting and HTML export. Supports tables, fenced code bl…

Split text by delimiter (including newlines, tabs and regex), by fixed character count, or every N lines — wit…

Remove duplicates from text by line, word, sentence or paragraph, with case-sensitivity and order-preserving o…

Reflow text to a column width — a CJK character counts as two columns, a Latin letter as one — breaking prefer…

Convert full-width digits, letters and punctuation to half-width and back, with per-category toggles (digits, …

Swap Western and Chinese punctuation in either direction. Context protection keeps the dot in example.com, the…

Pad every line to the same column width with left, right or centre alignment and a custom fill character — mea…

Convert Chinese characters to pinyin with tone marks, tone numbers or no tones, with a custom separator and po…

Analyse how often each character appears, with options for case sensitivity and ignoring whitespace. Fully pro…

Reverse text as a whole, word by word or line by line. A fun and practical string utility. Fully processed in …

Strip or normalise line breaks: remove all breaks, convert them to spaces, drop empty lines or collapse consec…

Teleprompter with auto-scroll, fullscreen, mirror mode, and adjustable font size and speed — great for recordi…

Compress JPEG, PNG and WebP images with adjustable quality and max width, batch supported. Fully processed in …

Convert JPG, PNG, GIF and BMP images to WebP at your chosen quality, batch supported. Fully processed in your …

Convert between PNG, JPEG and WebP at a chosen quality, batch supported. Fully processed in your browser.

Crop freely or with 1:1, 16:9 and 4:3 presets, rotate 90°, flip horizontally or vertically, and export PNG/JPE…

Convert images to Base64 data URIs and back, with drag-and-drop upload, live preview and multiple formats. Emb…

Add text or image watermarks with adjustable position, opacity and size. Runs entirely in your browser.

Create compliant ID photos with smart background replacement, supporting Chinese standard sizes for passport, …

Convert JPG, PNG and WebP images into a PDF with configurable page size, orientation and fit mode.

Turn colour images into grayscale, batch supported, fully inside your browser.

Split an image into a 3×3 grid for WeChat Moments, Weibo and Instagram sharing, entirely in your browser.

Turn JPG, PNG, WebP or BMP into a multi-size favicon.ico. Pick any combination of the seven sizes from 16 to 2…

Turn a photo into a round, squircle or square avatar. Drag and zoom to frame it, pick a transparent or solid b…

Record your screen, window or tab with optional audio. No software to install, and nothing leaves your device.

Convert PDF files to editable .docx documents, extracting text, paragraphs and images. Uploads are deleted rig…

Convert .docx and .doc files to PDF while preserving layout. Uploaded files are deleted as soon as conversion …

Render each PDF page to a high-resolution PNG or JPEG. Select specific pages, adjust quality, download individ…

Convert .xlsx, .xls and .ods spreadsheets to PDF while keeping table layout. Uploads are deleted after convers…

Convert .pptx, .ppt and .odp decks to PDF, one page per slide. Uploads are deleted after conversion.

Convert EPUB ebooks into stable PDF documents, preserving chapter structure and images. Files are deleted afte…

Extract EPUB body text into clean UTF-8 plain text for full-text search, analysis, TTS and LLM pipelines.

Convert Kindle MOBI books to reflowable EPUB, keeping chapters, cover and illustrations, ready for Kobo, Apple…

Convert Kindle MOBI ebooks to stable PDF documents, preserving chapters, images and text for printing or archi…

Convert Kindle AZW3 (KF8) ebooks to stable PDF documents while keeping chapters, images and formatting.

Online MD5 hash generator with 16/32-bit hex output and case conversion. Produce MD5 digests for integrity che…

Online hash generator covering MD5, SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512. Create digests for integrity…

Hash a whole column of data at once — one digest per line. Supports MD5, SHA-1, SHA-224, SHA-256, SHA-384, SHA…

Compute MD5 checksums for uploaded files to verify integrity and detect tampering.

Compute MD5, SHA-1, SHA-256 and SHA-512 hashes for uploaded files to confirm downloads are intact.

Generate strong random passwords with configurable length and character classes to resist brute-force attacks.…

Score a password by information entropy (length × log2 charset), then deduct for common passwords, repeated ru…

Decode and inspect JSON Web Tokens: read header and payload, check expiry and debug API authentication. Fully …

Online AES encryption and decryption with AES-128/192/256, CBC/GCM/ECB/CFB modes and PKCS7 padding. Fully proc…

Create JWTs with custom header and payload. Multiple signing algorithms supported for quick test tokens. Fully…

Validate Chinese ID numbers (18-digit and legacy 15-digit) in bulk. Four gates: length and characters, provinc…

Online DES and 3DES encryption with ECB/CBC modes and PKCS7 padding. Fully processed in your browser, keys nev…

Online RSA asymmetric crypto with key pair generation, public-key encryption and private-key decryption.

Change a file's MD5 by appending random data. Batch supported, up to 5 files.

Generate self-signed SSL/TLS certificates with RSA or ECDSA keys, multi-domain and IP SANs, custom validity, a…

Convert Unix epoch timestamps to readable dates and back. Supports second and millisecond precision with multi…

Compute the interval between two dates in years, months, weeks, days, hours, minutes and seconds. Fully proces…

Add or subtract days, weeks, months and years from any date to project a target date. Fully processed in your …

Calculate exact age, Chinese zodiac sign, total days lived and days to your next birthday from your birth date…

Create a countdown to any target moment, accurate to the second, with optional alerts.

Free online stopwatch with millisecond precision and lap splits. Automatically marks your fastest and slowest …

The classic Pomodoro technique: 25 minutes focused work followed by a 5-minute break to build deep focus habit…

Count actual working days between two dates, excluding weekends and optional custom holidays. Fully processed …

See the current time, date and weekday in cities worldwide, with timezone search and local time offsets.

Convert between milliseconds, seconds, minutes, hours, days, weeks, months and years with instant results.

Convert Gregorian dates to Chinese lunar dates with zodiac, solar terms and traditional festivals, covering 19…

A flip clock showing the current time with 12/24-hour formats, optional seconds and fullscreen — great for des…

Run several independent countdowns at once, each started, paused and reset separately — ideal for cooking, HII…

Find the best time to fall asleep or wake up based on 90-minute sleep cycles. Fully processed in your browser.

Estimate your due date from last menstrual period, IVF transfer or ultrasound data, and track gestational prog…

Track how many days, weeks and months old your baby is, with growth milestones along the way.

Live countdown to the Chinese national college entrance exam (Gaokao) in days, hours, minutes and seconds, aut…

Visualise how much of an expected lifespan you have lived, based on your birth date.

Compute expiry dates from production date and shelf life, or work backwards from expiry. Batch support with re…

A chronological table of Chinese dynasties from Xia to Qing, with dates, founding emperors and capitals.

Convert kilometers, meters, centimeters, millimeters, microns, nanometers, miles, yards, feet, inches, nautica…

Convert tonnes, kilograms, grams, milligrams, pounds, ounces, jin and liang with precise instant results. Full…

Convert between Celsius, Fahrenheit and Kelvin with accurate results for weather, science labs and baking. Ful…

Convert bits, bytes, KB, MB, GB, TB, PB, EB and their binary counterparts KiB, MiB, GiB, TiB, PiB and EiB. Ful…

Convert square kilometers, hectares, ares, square meters, mu, acres, square feet and more with instant results…

Convert cubic meters, liters, milliliters, gallons, cubic feet and cubic inches with instant results. Fully pr…

Convert meters per second, km/h, mph, knots, feet per second, Mach and the speed of light for commuting, aviat…

Convert numbers between binary, octal, decimal, hexadecimal and custom bases in real time with one-click copy.

Convert between decimal and IEEE 754 bit patterns at 32-bit single and 64-bit double precision. Accepts decima…

Convert joules, kilojoules, kilowatt-hours, calories, kilocalories, BTU and electronvolts with precision. Full…

Convert watts, kilowatts, megawatts, gigawatts, mechanical and metric horsepower, BTU/h, kcal/h, foot-pound pe…

Convert pascals, kilopascals, megapascals, bar, atmospheres, psi, mmHg, inHg, water columns and kgf/cm². Fully…

Generate RFC 4122 compliant unique identifiers, including UUID v1, v4 and time-sortable v7, in batches. Fully …

A complete HTTP status code reference from 1xx to 5xx, searchable and filterable by class. Fully processed in …

Estimate how many tokens your text consumes in major LLM models to keep prompt costs under control. Fully proc…

Parse and generate cron expressions with visual configuration, including second-level and Quartz style extensi…

Look up MIME types by file extension across documents, images, audio, video and more. Fully processed in your …

Generate TypeScript interfaces from JSON samples, handling nested objects, arrays and union types. Fully proce…

Browse control, printable and extended ASCII characters with search and category filters. Fully processed in y…

A complete reference of 254 flag emoji: every ISO 3166-1 code plus the EU, UN, England, Scotland and Wales. Cl…

A curated cheat sheet of the most useful Git commands, organised by category and searchable. Fully processed i…

Generate a draft-07 JSON Schema from a sample document with nested objects, array item inference and required …

Edit Mermaid diagrams with live preview for flowcharts, sequence, class, state, ER, Gantt, pie, mindmap and jo…

Identify browser, operating system and device information from any User-Agent string. Fully processed in your …

Generate title, description, keywords, canonical, Open Graph and Twitter Card tags in one go. Title and descri…

Build tracked URLs from the five standard UTM parameters. Existing query strings are preserved rather than clo…

Build a robots.txt from presets or custom rules: choose user-agents, add Allow/Disallow paths, set crawl-delay…

Turn one URL per line into a sitemaps.org-valid XML file, with shared lastmod / changefreq / priority, dedupli…

Generate JSON-LD for Article, Product, FAQPage, BreadcrumbList, Organization and Event, with required fields f…

Pick your stack (Node, Python, Java, Go, Rust, PHP, Ruby, C/C++, Swift, .NET, Flutter) plus editors, OSes and …

Run JavaScript in your browser and see output, errors and timing instantly. Supports console methods, async co…

Generate column-based CSV test data with configurable field types, custom separators and optional BOM. Fully g…

Generate column-based Excel test data — names, phone numbers, ID numbers, dates, amounts and more — and downlo…

Generate integer ranges with a step (forwards or backwards), geometric progressions, random integers (deduplic…

Convert JavaScript into JSFuck — code built from just []()!+. Great for learning language quirks and CTF puzzl…

Obfuscate and compress JavaScript with identifier renaming, string-array encoding, control-flow flattening and…

Turn JavaScript into AAEncode, a kaomoji-shaped representation of your code. Fun to look at and reversible; ou…

Encode JavaScript using only $, letters and underscores with JJEncode. A character-set obfuscation scheme like…

A server-side rendering sample page demonstrating how SSR feeds SEO-friendly markup from a backend handler.

Instantly see your public IP address with geographic details such as country, city and carrier.

Check whether ports on an IP or domain are reachable, in batches, with response times. Probing is performed by…

Query A, AAAA, MX, TXT, NS, CNAME and SOA records for a domain using our server-side resolver.

Measure connectivity and latency to a host with configurable probe counts, packet loss and min/avg/max statist…

Inspect TLS certificate validity, expiry, chain details and hostname matching to diagnose HTTPS misconfigurati…

Query domain registration data, expiry dates, name servers and registrar information for suffixes worldwide.

Compute network address, broadcast address, netmask, wildcard mask, host range and CIDR for IPv4 and IPv6 subn…

Expand short URLs and follow every redirect hop with status codes and timings. Works with t.cn, bit.ly and oth…

Open a WebSocket connection, send and receive messages with JSON pretty-printing, and debug interfaces live.

Transfer files and text between devices on the same network via direct WebRTC peer connection — no server in t…

Pull the original cover art from any Bilibili video — BV id, av id, bangumi ep/ss id, video URL or b23.tv shor…

Convert HEX, RGB, HSL and HSV values with shades and complementary colors. Fully processed in your browser.

Generate QR codes for text, URLs and contact cards with custom colors, size and high-resolution download.

Build linear and radial CSS gradients visually with live preview and one-click copy. Fully processed in your b…

Convert colours between HEX, RGB, HSL, HSV, CMYK and CSS custom properties, with luminance, contrast and hue a…

Build a full palette from one base colour with complementary, analogous, triadic, tetradic and split-complemen…

Create CODE128, EAN13, EAN8, UPC, CODE39 and ITF14 barcodes with custom colors and sizes. Download PNG or SVG.

Preview and edit SVG source with instant rendering and file download. Fully processed in your browser.

Preview text in any locally installed font or upload TTF, OTF, WOFF and WOFF2 files. Adjust size, weight, spac…

Generate colour swatch cards by family with values and contrast previews. Copy HEX, RGB or HSL in one click — …

A curated gallery of CSS animations with live previews — fades, slides, zooms, spins, bounces, shakes, flips a…

Generate solid-color images in any color and size with presets for 1080p, 2K and 4K. Download PNG or JPG. Full…

Check your display for dead pixels, bright spots and backlight bleed with multiple pure-color and contrast tes…

Make placeholder images at any size and colour, exported as SVG, PNG, JPEG, WebP, a Base64 data URI or plain C…

Tune multi-layer box-shadows visually: offset, blur, spread, colour, opacity and inset. Six presets cover subt…

Make a seal image in four layouts: round company seal, oval invoice seal, square personal seal and rectangular…

Get OS, browser, screen resolution, hardware and network details at once. Most checks run locally; the public …

Test your keyboard live with a virtual layout, key codes and press history — everything runs in your browser.

Check mouse buttons, scroll wheel and double-click behaviour with live coordinates, click counters and event h…

Measure your monitor's real refresh rate by sampling animation frames — handles 60Hz, 120Hz, 144Hz and beyond.

View live volume waveforms and spectrum analysis, record and play back, and inspect device info locally.

Preview your camera, capture snapshots and check resolution and device metadata without uploading anything.

Measure ambient noise through your microphone with a live gauge, noise-level classification and statistics.

Test gamepad buttons, sticks, triggers, D-pad and rumble motors for Xbox, PlayStation and generic USB controll…

Compute your Body Mass Index in metric or imperial units, with a healthy weight range and ideal weight guidanc…

Compute monthly payments and total interest for commercial, provident-fund and combined loans using equal-inst…

Four percentage questions in one place: what is B% of A, A is what percent of B, the percentage change from A …

Work out final prices, stacked discounts (store + member + coupon), whether a spend-threshold coupon beats a p…

Build a payslip item by item: base, performance pay, allowances, overtime at 1.5×/2×/3× on the statutory base,…

A real-time salary dashboard that turns your pay into a per-second figure and counts today's earnings up as yo…

Compute personal income tax with the 7-bracket progressive rates, social insurance and special additional dedu…

Convert between yearly, monthly, daily and hourly pay with configurable workdays and hours. Also computes your…

Convert amounts between Arabic numerals and Chinese financial capitals, accurate to the fen, for cheques, invo…

Convert between VAT-inclusive and exclusive amounts at 13%, 9%, 6%, 5%, 3%, 1% or a custom rate. Outputs the t…

Measure real fuel consumption with the fill-to-full method, work out trip and monthly fuel cost, and compare p…

Free online scientific calculator with trigonometry, logarithms, exponentiation, factorials and power function…

Split tips across 20 currencies with preset percentages, pre/post-tax toggles, per-person splits and rounding,…

Calculate basal metabolic rate and daily energy expenditure with Harris-Benedict, Mifflin-St Jeor and Katch-Mc…

Estimate body fat percentage using the US Navy method or the BMI method from height, weight and circumference …

Pick random winners from a list using cryptographically secure randomness, with repeat options and draw animat…

Track scores for multiple players with custom increments, decrements and live rankings — perfect for board gam…

Batch parse Chinese ID numbers (15 or 18 digits) to derive birth dates, exact ages, gender ratios and age dist…

Work out the correct Chinese kinship term from a relationship chain, covering paternal/maternal sides and seni…

Calculate social insurance and housing fund contributions with multiple city rate schemes, showing both person…

Predict possible blood types of children from the parents', or infer plausible parent combinations from a chil…

Compute credit-weighted GPA under five scales — standard 4.0, 4.3, Peking University, WES and 5-point — enteri…

Project compound growth from principal, rate, term and recurring contributions, with annual to daily compoundi…

Enter your options and spin the wheel to pick one at random — great for choosing lunch, weekend plans or a mov…

Roll d4 through d100 with dice-pool notation like 3d6+2d8+1. The dice are real polyhedra with rigid-body physi…

Flip a virtual coin with real randomness. Throw repeatedly and see the running tally of heads and tails.

Draw N names with a rolling animation and an optional no-repeat mode that remembers who was already picked, sp…

Measure how fast you react from signal to click, tracking best score and average across attempts.

Classic Minesweeper with 9×9, 16×16 and 16×30 boards. The first click is always safe and its neighbours stay c…

Play a freshly generated Sudoku with a guaranteed unique solution, in four difficulty levels — or paste your o…

Flip two cards to find matching pairs and clear the board. Three board sizes, with moves, time and your best r…

Measure your clicks per second over 5, 10 or 30 second rounds with live CPS statistics.

Whack the moles that pop up in 30 seconds. Consecutive hits build a combo multiplier while misses reset it, ac…

Play Rock Paper Scissors against the computer with a three-second countdown. Wins, draws, losses and your curr…

Test your mental arithmetic speed and accuracy with addition, subtraction, multiplication and division at sele…

Generate printable 5×5 bingo cards in one click. Number mode draws from the standard B-I-N-G-O column ranges w…

Generate batches of Chinese names (male, female or neutral), English names, usernames or fantasy character nam…

A categorised collection of Japanese-style kaomoji — happy, sad, angry, surprised, shy, resigned, cheering, lo…

Draw pixel art on 16×16, 32×32 or 64×64 canvases with brush, eraser, fill, eyedropper, undo and redo, plus a c…

Turn a photo, logo or screenshot into text art. Adjust output width, character ramp, brightness, contrast, inv…

Draw from the 22 Major Arcana — a single card for the day, or a three-card spread for past, present and future…

Shoot pins into a spinning disc without letting them collide. Ten levels with increasing speed — play instantl…

Simulate Windows BSOD, macOS kernel panic, Linux crash and Android ANR screens. Fullscreen supported, click to…

Fake Windows Update, macOS update, apt upgrade and Android system update screens. Fullscreen with click-to-exi…