Tools that stay on your device

Text, Chinese helpers and developer utilities — all in your browser, nothing uploaded.

Favorites

Popular

Count characters, Chinese chars, English words, lines and reading time.

Compare two texts and highlight differences.

Simplified ↔ Traditional Chinese

Convert between Simplified and Traditional Chinese (OpenCC).

Hanzi to Pinyin

Convert Chinese characters to pinyin with tone marks.

Beautify, minify and validate JSON in your browser.

YAML Format & Convert

Format, minify and validate YAML, or convert YAML ↔ JSON locally.

Beautify or minify SQL locally for MySQL, PostgreSQL, SQLite and more.

Password Generator

在浏览器本地用 Web Crypto 生成高强度随机密码，可排除易混字符并批量输出。不上传、免注册，适合临时需要强密码时使用。

在浏览器本地对比两个 JSON 的键级差异：新增、删除与修改。区别于文本 Diff，适合配置与 API 响应核对，数据不上传。

在浏览器本地格式化、压缩或校验 XML，并与 JSON 互转。使用 DOMParser，数据不上传，免费免注册。

Timezone Converter

在浏览器本地把同一时刻换算到不同时区，基于 Intl，不访问网络。支持 ISO 输入与 Unix 时间戳对照。

在浏览器用 Web Crypto 做 AES-GCM 加解密与 HMAC-SHA256。口令经 PBKDF2 派生，数据不上传，适合本地小密文处理。

URL Encode / Decode

Percent-encode or decode URL components.

Base64 Encode / Decode

Encode or decode Base64 text locally.

Convert between Unix time and readable dates.

Markdown ↔ HTML

Convert Markdown to HTML and back.

Test regular expressions with live matches.

Color Converter

Convert between HEX, RGB and HSL.

MD5, SHA-1, SHA-256 and more — computed locally.

QR Code Generator

Generate QR codes from text or URLs.

Files & Productivity

JSONPath Tester

Query JSON with JSONPath entirely in your browser.

HTML/CSS/JS Formatter

Beautify HTML, CSS and JavaScript with self-hosted Prettier.

Generate and verify RFC 6238 TOTP codes locally with otpauth URI.

Cron Expression Builder

Build cron expressions visually with explain and next run times.

Color Contrast Checker

WCAG contrast checks plus simple palette shades from a base hex.

JSON to TypeScript / Go Types

Infer TypeScript interfaces, Go structs, or Zod schemas from sample JSON locally.

Mermaid Diagram Editor

Edit Mermaid source and preview SVG locally with a self-hosted Mermaid build.

Convert length, weight, temperature and more.

Files & Productivity

Text

Clean, sort, replace and compare plain text

Remove Blank Lines

Delete extra blank lines; optionally keep one blank line between paragraphs.

Remove Duplicate Lines

Deduplicate lines while keeping first-seen order.

Count characters, Chinese chars, English words, lines and reading time.

Sort lines A–Z or Z–A, with optional unique and trim.

Find and replace text locally, with optional regex.

Clean Whitespace

Trim, collapse spaces and tidy whitespace.

UPPER, lower, Title, camelCase, snake_case and more.

Punctuation Convert

Convert between Chinese and English punctuation.

Add Line Numbers

Prefix each line with sequential numbers.

Compare two texts and highlight differences.

Chinese

Simplified/Traditional, pinyin and Chinese layout

Simplified ↔ Traditional Chinese

Convert between Simplified and Traditional Chinese (OpenCC).

Fullwidth ↔ Halfwidth

Convert fullwidth and halfwidth characters.

Text Wrap / Unwrap

Wrap text to a width or join wrapped lines.

Punctuation Tidy

Normalize Chinese punctuation and spacing.

Chinese Number Convert

Convert between Arabic and Chinese numerals.

Hanzi to Pinyin

Convert Chinese characters to pinyin with tone marks.

Chinese Text Clean

Clean messy Chinese text formatting.

Encode/decode Unicode escapes (\uXXXX).

Arrange text vertically for display.

Developer

JSON, encoding and everyday coding helpers

Beautify, minify and validate JSON in your browser.

YAML Format & Convert

Format, minify and validate YAML, or convert YAML ↔ JSON locally.

Beautify or minify SQL locally for MySQL, PostgreSQL, SQLite and more.

Turn titles into URL slugs; Chinese can use pinyin or keep characters.

Password Generator

在浏览器本地用 Web Crypto 生成高强度随机密码，可排除易混字符并批量输出。不上传、免注册，适合临时需要强密码时使用。

在浏览器本地对比两个 JSON 的键级差异：新增、删除与修改。区别于文本 Diff，适合配置与 API 响应核对，数据不上传。

在浏览器本地格式化、压缩或校验 XML，并与 JSON 互转。使用 DOMParser，数据不上传，免费免注册。

在浏览器本地格式化 TOML 或与 JSON 互转。轻量子集解析、不上传配置，适合 Cargo 与常见应用配置。

在浏览器本地格式化、校验 CSV，或与 JSON 互转。PapaParse 本地解析，处理引号与换行，数据不上传。

Timezone Converter

在浏览器本地把同一时刻换算到不同时区，基于 Intl，不访问网络。支持 ISO 输入与 Unix 时间戳对照。

Date Calculator

在浏览器本地做日期加减或计算两日相差天数。免注册、不上传，适合排期与简单期限估算。

HTML/CSS/JS Minify

在浏览器本地轻量压缩 HTML、CSS、JS，查看体积节省。不上传源码；复杂项目请再用专业构建工具确认。

在浏览器用 Web Crypto 做 AES-GCM 加解密与 HMAC-SHA256。口令经 PBKDF2 派生，数据不上传，适合本地小密文处理。

在浏览器本地生成或校验 bcrypt 哈希。使用自托管 bcryptjs，不上传明文；适合学习与离线比对，非生产唯一方案。

Hex / Binary / Base32

在浏览器本地互转文本与 Hex、Binary、Base32。UTF-8 处理、不上传，适合调试与编码对照。

在支持 CompressionStream 的浏览器里本地 Gzip 压缩或解压文本，结果以 Base64 展示，数据不上传。

在浏览器本地生成 CSS box-shadow、线性渐变、圆角与 Flex 代码。免注册、即时预览参数，适合快速拼样式。

robots.txt Generator

在浏览器本地生成 robots.txt：Allow/Disallow、Sitemap 与可选 AI 爬虫示例规则。不探测站点、不上传，复制即用。

CORS Headers Generator

在浏览器本地生成 CORS 响应头模板（原始 / Nginx / Cloudflare 注释）。不探测接口、不上传，避免 * 与 Credentials 冲突。

Encode and decode HTML entities.

URL Encode / Decode

Percent-encode or decode URL components.

Base64 Encode / Decode

Encode or decode Base64 text locally.

Convert between CSV tables and JSON.

Convert between Unix time and readable dates.

Generate random hex or alphanumeric strings.

Markdown ↔ HTML

Convert Markdown to HTML and back.

Test regular expressions with live matches.

Color Converter

Convert between HEX, RGB and HSL.

Generate UUID v4 identifiers in bulk.

MD5, SHA-1, SHA-256 and more — computed locally.

Decode JWTs locally without uploading tokens.

Explain five-field cron expressions.

JSONPath Tester

Query JSON with JSONPath entirely in your browser.

JSON Schema Infer & Validate

Infer a simple schema or validate JSON locally (Draft-07 subset).

HTML/CSS/JS Formatter

Beautify HTML, CSS and JavaScript with self-hosted Prettier.

RSA Key Pair Generator

Generate RSA-OAEP/PSS key pairs as PEM via Web Crypto.

Generate and verify RFC 6238 TOTP codes locally with otpauth URI.

htpasswd Generator

Create Apache htpasswd lines with bcrypt or apr1-md5 locally.

Cron Expression Builder

Build cron expressions visually with explain and next run times.

chmod Calculator

Convert between symbolic, octal and rwx Unix permissions.

CSP Header Generator

Build Content-Security-Policy header templates locally.

llms.txt Generator

Generate llms.txt / llms-full.txt from site fields locally.

JSON-LD Schema Markup

Generate FAQPage, Organization, WebApplication and HowTo JSON-LD.

Color Contrast Checker

WCAG contrast checks plus simple palette shades from a base hex.

JSON to TypeScript / Go Types

Infer TypeScript interfaces, Go structs, or Zod schemas from sample JSON locally.

Mermaid Diagram Editor

Edit Mermaid source and preview SVG locally with a self-hosted Mermaid build.

Files & Productivity

Images, QR codes, timestamps and units

Image Compressor

Compress images in the browser before download.

Files & Productivity

QR Code Generator

Generate QR codes from text or URLs.

Files & Productivity

Strip or simplify HTML markup.

Files & Productivity

Image ↔ Base64

Convert images to Base64 data URLs and back.

Files & Productivity

Convert length, weight, temperature and more.

Files & Productivity

How it works

Every tool runs in your browser. Text, images and files are not uploaded. No account required. Each tool has its own URL you can bookmark. Favorites stay in localStorage. Works in Safari and Chrome.