Case Converter Manual
One reference for all conversion modes, keyboard shortcuts, export formats, text handling and known limits.
Quick start
- Open the Case Converter and paste text in Your text. Or choose Open text file to use a local .txt or .md document.
- Select one of five common conversions. For developer naming formats and alternatives, open More cases.
- Review the read-only Result. Choose Copy result or select the download format.
The result always comes from the original editor text, not the last converted result. Choose Use as input if you intentionally want a new starting point.
All 13 conversion modes
Modes are grouped by their effect. Writing-oriented modes preserve spaces, tabs, newlines and punctuation. Developer naming modes deliberately rebuild words and separators, so use the original preview as reference.
| Mode | What it does | Example |
|---|---|---|
| UPPERCASE | Uppercases all cased letters. | HELLO WORLD |
| lowercase | Lowercases all cased letters. | hello world |
| Sentence case | Lowercases text then capitalizes the first letter, and letters after a period, exclamation mark, question mark or line break. | Hello. How are you? |
| Title Case | General English style: uppercase initial letters of most words while keeping a small list lowercase unless first or last. | The Art of Writing |
| Capitalize Words | Capitalizes first letter of every word. | The Art Of Writing |
| tOGGLE cASE | Swaps lowercase and uppercase for letters, if a case mapping exists. | hELLO wORLD |
| aLtErNaTiNg | Alternates lowercase and uppercase for letters only, starting lowercase. | hElLo WoRlD |
| camelCase | No separators, first word lowercase, later words capitalized. | helloWorld |
| PascalCase | No separators, initial capital on every word. | HelloWorld |
| snake_case | Lowercase words joined with underscores. | hello_world |
| kebab-case | Lowercase words joined with hyphens. | hello-world |
| CONSTANT_CASE | Uppercase words joined with underscores. | HELLO_WORLD |
| dot.case | Lowercase words joined with periods. | hello.world |
How Title Case differs from word capitalization
Title Case uses the general-purpose lowercase word list a, an, and, as, at, but, by, for, in, nor, of, on, or, per, so, the, to, via, vs, yet. These words are still capitalized at the beginning and end. The tool lowercases other letters before capitalization, so it cannot preserve acronyms, brands or proper names.
This is not an APA, MLA, AP or Chicago style preset. For documents requiring a specific editorial standard, review the final text against that standard.
Language and Unicode rules
Under Language settings you can select English (default), Turkish or German. Letter case mapping uses JavaScript's Unicode locale-aware upper/lowercase methods under that selected locale. For instance, Turkish lowercase i uppercases to İ, while English uses I.
Some transformations change string length. For example, German straße may uppercase to STRASSE. Accents and emoji can contain multiple underlying Unicode units; the displayed code point count is not the same as the number of user-perceived grapheme clusters.
The English small-word list for Title Case is used regardless of the selected language. Sentence boundaries use explicit punctuation/newline rules and do not infer grammar or special abbreviations.
Open, copy, and download
Opening files
The Open text file action accepts .txt and .md files up to 1 MB. File text is read with browser-local APIs and is not uploaded. Files longer than 500,000 UTF-16 code units are rejected. The tool does not open DOCX, PDF or HTML as formatted documents.
Copy
Press Copy result to copy the entire converted text. If browser clipboard permission is unavailable, the result is selected so you can use your usual copy command.
Download formats
- TXT: the exact visible converted text. The browser editor may normalize CRLF line endings to LF.
- Markdown: the exact converted text saved with the .md extension. This action does not generate headings, formatting or HTML.
- JSON: an object containing the original source, converted result, mode name and locale.
Downloads are created using a local Blob and a sanitized filename. There is no automatic upload or server save.
Keyboard shortcuts and Undo
| Action | Shortcut |
|---|---|
| Choose first five conversions | Alt + 1…5 |
| Copy result | Ctrl / Cmd + Enter |
| Undo edits in input | Use your browser's native Ctrl / Cmd + Z, or the Undo button for recent source snapshots |
Undo keeps a small number of recent source snapshots in page memory. It is not a version history service. Copy and downloads do not automatically overwrite the original. Switching case never alters your input.
Limits, assumptions, and privacy
- The editor supports up to 500,000 UTF-16 code units of source text. The character limit is expressed in this technical unit; a displayed code point count can differ.
- Files must be <=1 MB and have the .txt or .md extension.
- Identifier conversions strip formatting separators and punctuation. Complex acronyms and emojis may produce results that need manual review.
- Sentence Case does not infer proper names, acronyms or abbreviations; e.g., it may change
iPhoneorNASAunexpectedly. - Title Case is a practical general convention rather than editorial style-guide compliance.
- There is no autosave, local storage or account. Closing or refreshing this page loses text unless you copy or download it first.
The converter processes text in this browser; it does not submit your source or result to a remote conversion API. The website is intended to use third-party advertising when approved and enabled. Advertising providers may use cookies and process page, browser or device information separately from the converter. Ad serving and any applicable consent controls must be verified before activation. See the Privacy Policy for further information and advertising choices.
Troubleshooting
Nothing appears in Result
Make sure the input has text and is below the character limit. Press any conversion button and check the status line.
Text looks different than expected
Check whether a developer naming style is selected. These are intentionally lossy. For writing, switch to uppercase, lowercase, sentence case, Title Case, or Capitalize Words.
Clipboard is blocked
Some browser configurations disallow clipboard access. Click in Result, select the text, and use your browser's ordinary copy command.
A file won't open
Check its extension and size. The tool accepts only .txt and .md plain-text files up to 1 MB.