A fast, private, 100% client-side toolkit. No server, no upload.
Beautify, compress, validate and escape JSON.
Visualize JSON as a collapsible tree.
Convert JSON arrays to CSV format.
Convert between JSON and XML.
Convert between JSON and YAML.
Edit JSON with live validation and tree preview.
Sort JSON keys alphabetically.
Convert between JSON and query strings.
Generate random mock test data with faker.js.
Generate Java/Go/TS/Python/C#/SQL from JSON.
Convert between JSON and TOML configs.
JSON5 with comments / trailing commas / unquoted keys / Infinity, to standard JSON and back.
Convert between Unix timestamp and date with timezone.
Parse cron expressions into human-readable text.
Track multiple time zones at once.
Days, weeks, months between two dates.
Convert Solar/Lunar, Gan-Zhi, zodiac.
Working days between dates.
Centisecond stopwatch with multi-lap timing and keyboard shortcuts.
Live days / hours / min / sec to an event; save events locally.
Perpetual calendar with lunar dates, solar terms, Gan-Zhi and Yi/Ji.
Encode and decode Base64 in your browser.
Percent-encode or decode URLs and query params.
Compute MD5, SHA-1/256/384/512, CRC32 and HMAC.
Convert between binary, octal, decimal and hex.
Convert text to Unicode/hex escapes and back.
Convert files or images to Base64 data URLs.
Text ↔ International Morse Code.
Play Morse with Web Audio tones, adjustable pitch / WPM, WAV export.
URL ↔ Thunder / qqdl / FlashGet interconvert.
Text ↔ Base32 / Base58 (Bitcoin) / Base62, BigInt-based.
Full ASCII + extended tables, Unicode codepoint ↔ char converter (UTF-8 / UTF-16).
Generate RFC-4122 v4 UUIDs securely.
Generate a downloadable QR code image.
Pick colors, convert HEX/RGB/HSL, generate palettes.
Preview Lottie animations with play/pause/loop.
Generate strong passwords with custom length and charset.
Generate barcodes (CODE128, EAN13, UPC, etc.).
Generate placeholder text in paragraphs.
Spin the wheel to pick a random option.
Search and copy FA6 icon HTML.
WCAG color contrast ratio.
Baidu / Google hot searches.
Complementary / analogous / triadic / tetradic / monochrome palettes + CSS / JSON / Tailwind export.
Batch-generate random codes, crypto-unbiased, prefix / suffix / separators, Luhn option.
Local sticky notes: colors, pin, search, drag-to-reorder. Saved in browser.
shields.io-style SVG badges: label / value / color / style / logo, URL + Markdown + SVG.
Test JavaScript regular expressions live.
camelCase, snake_case, kebab-case, PascalCase.
Compare two text blocks and highlight differences.
Dedup, sort, trim, case convert and more.
Bulk check email format, valid vs invalid.
Title to URL-friendly slug.
Number to English words / Chinese.
Translate 20+ languages, auto-detect.
Render text as large character blocks.
CSV / TSV → Markdown / ASCII / HTML table.
Remove duplicate lines: keep-first or sort, case / trim options.
Word / n-gram frequency + density for SEO copy review.
180+ IT / business / medical / chat abbreviations, CN + EN.
Reverse, shuffle, strip blank lines, number lines, column pick, vertical, full/half-width.
CSV ↔ JSON / TSV, preview & edit as table, custom delimiter / quoting / header.
Characters / words (EN+CN) / sentences / paragraphs / lines / reading time / top keywords, live.
Live KaTeX rendering of LaTeX formulas with 40+ templates.
Measure WPM, accuracy and errors with Chinese / English passages.
Emoji, punctuation, math, box-drawing, currency, Greek, arrows — one-click copy.
Chinese simplified / traditional (TW/HK) converter.
Scan copy for China ad-law / e-commerce / short-video bans.
Convert characters to pinyin with tones, polyphones resolved.
Look up radical, stroke count and structure.
Find Chinese homophone puns (耗子尾汁 / 鸭梨山大).
Generate 藏头诗 from a phrase — fun, not literary.
Count characters, words, lines and reading time.
China ID check + extract birthdate / gender / region, 15→18 conversion.
200+ Chinese name characters with meanings & Wu-Xing, random suggestions, favorites.
Hundred Family Surnames: browse single & compound with Pinyin and classic rank.
Idiom (成语) look-up, word-chain game and structure filters.
Two-part allegorical sayings — search, browse, random.
Synonyms and antonyms for common Chinese words.
Character / idiom / thing riddles — guess, search, filter.
Tang & Song classics search + Feihualing.
Full text of 三字经 / 千字文 / 百家姓 / 弟子规.
Classic Chinese & Western quotes — search + random.
Spring / famous / trade couplets — search & filter.
Look up a Chinese city by name, area code, ZIP or plate.
Year → animal, personality, matches, fortune.
Birthday → sign, element, personality, matches.
Search dream motifs for traditional meanings.
Dates, meaning, customs and health tips.
Write Markdown with live preview and export.
Excel-like sheets with formulas and charts.
View, merge, split, rotate PDF pages.
Full-featured editor with HTML/Markdown export.
Import .docx, edit and export HTML.
View DXF files with pan, zoom and layers.
View STEP/IGES/BREP 3D models, rotate and export.
View and edit CSV as a table.
Draw shapes and import/export DXF.
Square / dot / hex / isometric / 米字格 paper, print or SVG / PNG.
Chinese handwriting practice sheets, tracing or empty.
SRT / WebVTT / ASS / SSA interconvert + timeline offset.
Infinite hand-drawn canvas, export PNG/SVG.
Freehand canvas with eraser and undo.
Sign and export a PNG image.
Canvas whiteboard, runs offline.
Markdown outline to live mind map, SVG export.
Interactive mind map, add/edit nodes, JSON export.
Flowcharts, architecture, UML diagrams.
Symmetric encryption and decryption.
Generate RSA keys, encrypt and decrypt.
Decode JWT tokens and inspect header and payload.
Encrypt/decrypt Cisco Type 7 passwords.
Parse X.509 PEM certificates.
Detect hash algorithm type.
Hand-rolled RC4 (KSA + PRGA), hex / Base64 output.
Create cubic-bezier() easing curves visually.
Create linear, radial and conic gradients.
backdrop-filter frosted-glass cards with live preview.
Soft-UI dual-shadow buttons and cards.
Multi-layer box-shadow / text-shadow with inset.
Visual flex layout, copy-direction/justify/align/gap.
Template-columns, gap, justify/align-items live.
12 @keyframes presets, live preview, copy-ready CSS.
background-clip: text gradient text, linear / radial, live preview, copy CSS.
Beautify or minify code with Prettier.
Tabs/spaces, trim, strip comments.
Beautify and format SQL queries.
Format, beautify and validate XML.
Prettify / minify GraphQL queries, lightweight tokenizer.
highlight.js code coloring with theme switch and HTML copy.
Escape / unescape HTML entities + cheat sheet.
Convert curl command to Python / JS / Node / PHP / Go.
Write HTML and see live rendered preview.
User-agent, rules, sitemap, with one-click presets.
URL list → standard sitemap with lastmod/freq/priority.
title/description/OG/Twitter + SERP preview.
HTML ↔ document.write / template literal / JSX / PHP echo.
Swift / Kotlin / Dart / Rust / Ruby / PHP / Scala types from JSON.
Press any key to see its keyCode and code.
Parse cookies and HTTP headers, edit, export.
Searchable HTTP status code reference.
Extension ↔ MIME type lookup.
Decode UA into browser, engine, OS and device.
Connect ws/wss, log messages with timestamps and direction.
Internationalized domains ↔ ACE (xn--) conversion.
Integer-GB partition MB value with formula comparison.
100+ common commands with examples and category filter.
Run XPath over XML/HTML via document.evaluate.
On-screen ruler with draggable guides, px + mm distance.
Metacharacters, classes, quantifiers, anchors, lookarounds, flags + common patterns, searchable.
Postman-like HTTP client: params / headers / body, response status / time / size, optional CORS proxy.
Obfuscate JavaScript to protect source code.
SHA-1/256/384/512, MD5, CRC32 of any file.
Identify file type from its header bytes.
Apache .htpasswd: BCrypt / APR1 / SHA1.
PKCS#10 CSR + RSA private key, node-forge, local-only.
Text ⇄ gzip ⇄ Base64 via native CompressionStream, with size + ratio.
Compress PNG, JPG and WebP in your browser.
Format, minify and preview SVG images.
Edit images with brush, shapes, text and filters.
Pro photo editing: layers, adjustments, filters, export.
Crop, rotate, color, stickers, text and filters.
Remove image backgrounds with on-device AI.
Add text/image watermark, single or tiled, batch.
BPM 40-240, 2/3/4/6 time signatures, accented downbeat, Web Audio.
Mic + autocorrelation pitch detection, EADGBE / chromatic.
Waveform trim, fade in/out, export WAV (PCM 16-bit).
Convert PNG / JPG / WebP with quality slider.
Generate multi-size .ico favicon from PNG.
Generate PNG/SVG placeholder images by size and color.
Slice an image into 2×2 / 3×3 / 3×4 tiles.
Stamp National Day / Christmas / Spring / Mid-Autumn themes on a photo.
Stamp Impact top/bottom text onto an image or built-in template.
Extract every frame of an animated GIF as PNG.
Drag a selection, crop every frame, re-encode.
Scale GIF by pixels or percent, keep aspect ratio.
Material / Tailwind / brand colors, CSS gradients, CN & JP traditional colors.
Merge icons into one PNG sprite + .icon CSS classes with background-position.
Recursive-backtracking DFS maze, BFS shortest path, PNG / SVG export.
Ishihara-style plates generated on canvas, screen normal / red-blind / green-blind.
Calculate network, broadcast and host range.
Parse VMess/VLESS/Trojan/SS node URIs.
Parse/generate magnet URIs and info-hash.
IP ↔ decimal/binary/hex conversion.
Batch random IPv4 / IPv6 / MAC, private ranges + vendor OUI.
Expression evaluator with math.js.
Add/sub/mul/div fractions with steps + GCD/LCM.
Reduce fractions to lowest terms with GCD steps, improper ↔ mixed, compare.
Four percent modes: of, ratio, growth, reverse.
BMI + China / WHO grade, healthy weight range, body-fat %.
D4–D100, 1-20 dice, totals, max/min, history.
3D animated toss with stats and streak tracking.
Red → green, 5–10 rounds, average / fastest / slowest + rank, early-click detection.
Arabic ↔ Roman numeral conversion.
Number to Chinese RMB uppercase.
Pie / bar / line / scatter / radar on pure canvas + PNG.
Thousands / scientific / Chinese / percent / precision / ordinal, live.
Bubble / selection / insertion / quick / merge / heap on canvas, with compare & swap stats.
Greatest common divisor & least common multiple of integers with prime factorization.
P(n,k), C(n,k), n^k, with-repetition variants and factorial, exact BigInt.
Solve / play the 24 game: enumerate every + − × ÷ expression reaching the target.
Convert length, weight, temperature, data and more.
Calculate screen PPI, dot pitch and aspect ratio.
bit / B / KB / MB / GB / TB / PB / EB, 1024 vs 1000.
Haversine great-circle distance + bearing, multi-leg total.
Pick a standard carton + dim-weight for shipping.
ISO A/B/C, US, Chinese paper sizes + matcher.
Clothing / shoes / underwear / ring sizes across regions.
80+ countries: mains voltage, frequency, plug type.
China IIT cumulative withholding (2024 brackets).
Monthly payment, equal-payment/principal.
Parallel count-up / count-down timers with beep.
25/5/15 work–break cycles with beep + notifications.
Spin the food wheel, exclude & save picks.
Child ABO types from parents; infer the other parent.
Chinese relative titles from a relationship chain.
All 118 elements with category colors, search and detail.
Dynasty timeline with capitals, founders and events.
150+ countries: capital, currency, language, dial code.
985 / 211 / 双一流 lookup by province and tag.
100+ top-level domains: meaning, category, country.
Fullscreen scrolling text banner for concerts / pickups.
Real-time format check for 16 countries' passport numbers + rule table.
Number to uppercase words for USD / EUR / JPY / GBP / CNY and 10+ currencies.
Future value with principal, rate, years, recurring contributions and compounding frequency.
First 6 digits → issuing bank & debit/credit type.
Check a number against the traditional 81-number fortune table.