A collection of pure front-end mini tools. Everything runs locally in your browser — your files are never uploaded to any server.
Frequently Used
English-Chinese Smart Dictionary Auto-detect language to look up English words or translate Chinese text. Built-in ECDICT 3.4M-entry local dictionary sharded by first letter and cached in IndexedDB for offline use, online API for detailed definitions and examples, browser speech synthesis for pronunciation, 100% local processing, nothing uploaded Open tool Online Translator Type text and pick source/target languages to translate online between 50+ languages. Independent from the English-Chinese Dictionary, focused on free multi-language translation. Auto-detect source language, Baidu / Youdao / Edge / MyMemory translate side by side, pure frontend calling third-party services, no self-hosted backend Open tool Markdown CN → EN (Local) Paste Chinese Markdown and get English Markdown in one click. Runs fully offline on local Ollama + Qwen2.5, nothing uploaded. Auto-preserves code blocks / front matter / link and image URLs, locks glossary terms from translation. Built for bilingual blogging. Open tool
Audio & Video
MediaInfo Viewer Drop an audio/video file and get MediaInfo-grade technical details parsed locally (container, duration, bit rate, resolution, video and audio codecs, colour info, subtitle tracks). Four views — tree / text / XML / JSON — with one-click copy, plus an audio/video parameter reference and GOP frame-structure diagrams. 100% local, nothing uploaded Open tool Audio Metadata Viewer Drop an audio file to parse locally its metadata tags (title, artist, album, track, year, genre, lyrics, ReplayGain …) and technical parameters (codec, sample rate, bit depth, channels, bitrate, duration, lossless or not), plus embedded cover art. Supports FLAC / ALAC / APE / WAV / AIFF / DXD / MP3 / AAC / M4A / WMA / OGG / OPUS / MP2 / DSF / DFF / AC-3 / DTS and M3U / M3U8, with a notes / validity reference column; formats the browser cannot play (DSD / APE / WMA / AC-3 / DTS) can be transcoded with the built-in ffmpeg. 100% local, nothing uploaded Open tool Local Music Player Pick a music folder; the browser traverses it locally and builds a playlist of all supported tracks, switch/shuffle/repeat anytime, with a live frequency-band visualizer for L/R channels. Supports FLAC / ALAC / APE / WAV / AIFF / DXD / MP3 / AAC / M4A / WMA / OGG / OPUS / MP2 / DSF / DFF / AC-3 / DTS (17 formats); formats the browser cannot play are auto-transcoded with the built-in ffmpeg, fully local Open tool
Images & Graphics
Image to AVIF Convert PNG / JPEG / WebP / GIF to AVIF in batch, animated images transcoded frame by frame, 100% local in-browser conversion, nothing uploaded (WASM libaom) Open tool Image Color Palette Upload an image to extract dominant colors via pixel analysis. Three quantization algorithms (K-Means / Median Cut / Histogram), adjustable color count and sampling precision, results as HEX + RGB with generated Swift / Objective-C / CSS / Android XML code snippets, 100% local processing, nothing uploaded Open tool Color Format Converter Convert between HEX / RGB / HSL / SwiftUI / UIColor / Android / CSS color formats instantly. Real-time linked output, eyedropper picker, preset swatches, one-click copy, 100% local processing, nothing uploaded Open tool Image Format Converter Convert PNG / JPEG / GIF / BMP / AVIF / HEIC etc. to WebP / JPEG / PNG, 100% local in-browser conversion, nothing uploaded Open tool Image Metadata Viewer Drop an image to parse full technical metadata locally — format, dimensions, bit depth, color type, alpha channel, animation, EXIF camera info and ICC color profile. Supports PNG / JPEG / GIF / WebP / AVIF / HEIC / TIFF / BMP and more, 100% local parsing, nothing uploaded Open tool QR Code Generator & Parser Generate QR code images from text (selectable error-correction level, download as PNG) and parse QR images back to text or links, 100% local processing, nothing uploaded Open tool Image Privacy Sanitizer Upload an image to view all of its EXIF metadata (GPS coordinates, device model, shooting time, etc.), strip every metadata field with one click and download the sanitized image, with a before/after file-size and metadata-ratio comparison. Parses JPEG/PNG entirely locally, nothing uploaded Open tool 3×3 Grid Crop Upload an image and split it into a 3×3 grid of 9 tiles with one click. Subject-anchor protection auto-adjusts the crop grid so people or main subjects are never cut off, with manual grid nudge, preview of all 9 tiles and ZIP download. 100% local processing, nothing uploaded Open tool Lottie Animation Viewer Upload Lottie JSON or dotLottie files to preview animations with play controls, seek bar, speed adjustment, loop toggle, background color switching, animation info display and frame export to PNG, 100% local rendering, nothing uploaded (lottie-web + JSZip) Open tool PAG Animation Viewer Upload PAG files to preview animations with play controls, seek bar, speed adjustment, loop toggle, background color switching, animation info display and frame export to PNG, powered by Tencent libpag WASM engine, 100% local rendering, nothing uploaded Open tool
Encoding & Conversion
Base64 Encode / Decode Convert text to and from Base64, supports standard and URL-safe (Base64URL) variants, encode, decode, one-click copy, 100% local processing, nothing uploaded Open tool Number Base Converter Real-time linked conversion between binary / octal / decimal / hexadecimal, arbitrary big integers supported, 100% local computation, nothing uploaded Open tool String Hash Enter a string and generate MD5 / SHA1 / SHA256 / SHA384 / SHA512 on click, with case toggle and one-click copy, 100% local computation, nothing uploaded Open tool JSON ↔ Swift Converter Paste JSON to generate Swift Codable structs, or paste a Swift struct to generate sample JSON. Supports nested objects, snake_case naming and automatic CodingKeys, Swift / Objective-C dual-language output, 100% local, nothing uploaded Open tool Timestamp Converter Real-time clock with millisecond precision, Unix timestamp ↔ date conversion with Apple NSDate Double format support, auto-detect seconds/milliseconds/decimal timestamps, Swift / Objective-C API examples, 100% local, nothing uploaded Open tool URL Encode / Decode Convert text to URL encoding (%20%2F) and back, supports encodeURIComponent and encodeURI modes, two-way one-click swap and one-click copy, 100% local processing, nothing uploaded Open tool JWT Online Parser Paste a JWT to auto-decode Header and Payload into a JSON tree, highlight the expiration time and count remaining days, built-in HMAC-SHA256 signature verification and tamper demo, 100% local parsing, nothing uploaded Open tool UUID / ULID Generator One-click batch generation of 1 / 10 / 100 UUID v4 and ULID, copy a single one or all, regenerate a new batch, 100% local generation, nothing uploaded Open tool Regex Tester Real-time highlighting of all regex matches against test text, shows capture groups and match count, with backtracking / complexity monitoring and warnings for catastrophic backtracking patterns, 100% local computation, nothing uploaded Open tool
Data Processing
JSON Tools All-in-one JSON toolkit: tree viewer (expand/collapse, search, image-link hover preview), format/minify/sort by key, lenient parsing with auto-repair (trailing commas/single quotes/unquoted keys/comments), copy and download .json, precise error position. 100% local, nothing uploaded Open tool XML Tools XML tree browsing, formatting (pretty-print), minify, one-click copy and download, 100% local processing, nothing uploaded Open tool SQLite Database Manager Browser-based SQLite manager run entirely in your browser—create/open .sqlite files, run SQL, browse & edit table data, import/export CSV and SQL. Powered by sql.js, fully local Open tool
Developer Tools
Geocoding Lookup Geocode and reverse-geocode in the browser — enter coordinates to get an address, or an address to get coordinates. Choose Tencent / Amap (China) or Google / OpenStreetMap (overseas), with WGS-84 / GCJ-02 / BD-09 conversion and the full raw JSON response Open tool CocoaPods Quick Reference Quick reference for CocoaPods CLI commands and Podspec DSL with 111+ entries covering syntax, flags, usage examples and notes. Category filter and real-time search. 100% local, nothing uploaded Open tool