大小写转换Case Converter
英文文本大小写转换Convert English text between uppercase, lowercase and more.
关于 大小写转换About Case Converter
写标题、枚举名、SQL 关键字或变量名时，经常需要在大小写风格之间切换。本工具支持英文文本一键转换为大写、小写、标题_case、句首大写等常见风格，复制即用。Writing titles, enum names, SQL keywords or variables often means switching between case styles. This tool converts English text to uppercase, lowercase, Title Case, Sentence case and other common styles in one click, ready to copy.
使用方法How to Use
- 输入或粘贴英文文本。Type or paste English text.
- 点击目标大小写样式按钮。Click the target case-style button.
- 复制转换结果使用。Copy the converted result.
常见问题FAQ
支持哪些大小写风格？Which case styles are supported?
页面提供全大写、全小写、标题大小写、句首大写等常用按钮，覆盖文档写作与代码命名的大部分场景。The page offers ALL CAPS, all lowercase, Title Case, Sentence case and other common buttons, covering most writing and naming needs.
非英文字符会受影响吗？Are non-English characters affected?
不会。大小写转换只作用于英文字母，中文、数字与符号原样保留。No. Case conversion only touches English letters; Chinese, digits and symbols pass through unchanged.
标题大小写的规则是什么？What is the Title Case rule?
每个单词首字母大写。严格的英文出版规范中冠词、介词等小词不大写，日常使用按“每词首字母大写”即可。Capitalize the first letter of each word. Strict publishing styles keep small words (articles, prepositions) lowercase, but for everyday use capitalising every word is fine.
相关阅读Related Reading
Lorem Ipsum 不只是占位符：排版密度、断行测试与设计稿填充指南Lorem Ipsum Is More Than Placeholder: Typographic Density, Line-Break Testing and Mock-Filling Guide
设计稿里那堆 "Lorem ipsum dolor sit amet" 不是随便乱打的拉丁文，它有近五百年的历史。本文聊聊它的由来，以及如何用占位文本真正测出行高、断行、溢出和响应式布局的问题，而不是只填满画布That "Lorem ipsum dolor sit amet" in your mockups is not random Latin — it has a history of nearly 500 years. This article covers its origins and how to use placeholder text to actually reveal line-height, line-break, overflow and responsive layout issues, not just fill the canvas.
大小写转换不简单：土耳其语 i、Unicode 大小写与 locale 陷阱Case Conversion Is Not Trivial: Turkish i, Unicode Case Mapping and Locale Traps
`"I".toLowerCase()` 谁不会写？但在土耳其语 locale 下它返回的不是 "i" 而是 "ı"。本文从这个经典 bug 出发，讲清 Unicode 大小写映射的一对多、无条件映射与 locale 映射，以及数据库、URL、HTTP 头里的大小写坑Who can't write `"I".toLowerCase()`? But under a Turkish locale it returns "ı", not "i". Starting from this classic bug, this article explains Unicode one-to-many case mapping, unconditional vs locale-aware mapping, and the case pitfalls in databases, URLs and HTTP headers.
相关工具Related Tools
文本去重/去空行Text Deduplicator
去除文本中的重复行和空行Remove duplicate lines and empty lines from text.
字数统计Word Counter
统计文本字符数、词数、行数Count characters, words and lines in text.
文本对比Text Diff
在线对比两段文本的差异Compare differences between two pieces of text online.
Lorem Ipsum 生成Lorem Ipsum Generator
生成Lorem Ipsum占位文本Generate Lorem Ipsum placeholder text.