Online Case Converter
Convert text into 20 case styles – uppercase, lowercase, title case, camel case, snake case, and more, instantly.
What Does the Case Converter Do?
This tool converts text between 20 different case styles instantly, covering everyday writing formats, programming naming conventions, and novelty text styles. Paste or type your text on the left, pick a case style on the right, and the conversion happens live in your browser.
A stats panel below the case buttons tracks your Words, Characters, Sentences, and Paragraphs as you work, and an Original button lets you reset back to your untouched input at any time. Need a deeper breakdown, readability, reading time? Our standalone Word Counter covers that, and if your text is locked inside a PDF, the PDF Word Counter pulls it out and counts it for you.
Unlike most case converters, our Sentence case is grammar-aware, it recognizes abbreviations, acronyms, and URLs instead of blindly capitalizing after every period. See exactly how in the section below.
Common Writing Cases
lower case, UPPER CASE, Sentence case, Title Case, and Capital Case cover everyday formatting needs, headlines, titles, captions, and normalized body text. Sentence case and Title Case are grammar-aware rather than simple find-and-replace, see the accuracy section below for exactly how.
Programming and Naming Cases
camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case, dot.case, path/case, Header-Case, Pascal_Snake, and no case match the naming conventions used across variables, functions, file names, URL slugs, CSS classes, and environment variables in most programming languages and frameworks.
Novelty and Stylistic Cases
aLtErNaTiNg Case, Inverse Case, Random Case, Reverse Case, and Upside Down text are built for social captions, memes, usernames, and playful formatting where standard grammar rules don’t apply.
| Case Type | Example | Commonly Used For |
|---|---|---|
| lower case | hello world example | Casual text, usernames |
| UPPER CASE | HELLO WORLD EXAMPLE | Headlines, emphasis, constants |
| Sentence case | Hello world example. | Normalizing pasted or all-caps text |
| Title Case | The Lord of the Rings | Article and book titles |
| Capital Case | The Lord Of The Rings | Headings, product names |
| camelCase | helloWorldExample | JavaScript variables, JSON keys |
| PascalCase | HelloWorldExample | Class names, React components |
| snake_case | hello_world_example | Python variables, database columns |
| CONSTANT_CASE | HELLO_WORLD_EXAMPLE | Environment variables, constants |
| kebab-case | hello-world-example | URL slugs, CSS classes, file names |
| dot.case | hello.world.example | Config keys, namespaces |
| path/case | hello/world/example | File paths, routes |
| Header-Case | Hello-World-Example | HTTP headers |
| no case | hello world example | Stripping formatting back to plain words |
| Pascal_Snake | Hello_World_Example | Mixed naming conventions |
| aLtErNaTiNg | hElLo WoRlD ExAmPlE | Social captions, mocking text memes |
| Inverse Case | hELLO wORLD eXAMPLE | Flipping existing capitalization |
| Reverse Case | elpmaxe dlrow olleh | Puzzles, novelty text |
| Random Case | hELlo WorLD exampLE | Stylized captions |
| Upside Down | ǝldɯɐxǝ plɹoʍ ollǝɥ | Novelty and social posts |
Original (Reset)
Every conversion is non-destructive. Click Original at any time to instantly restore your text exactly as you first typed or pasted it, with no need to retype or undo repeatedly.
Browser-Based Processing
Your text never leaves your device. Every conversion runs locally in your browser, nothing is sent to a server, stored, or logged. No account required.
Upload and Download
Upload a TXT or DOCX file to convert its content instantly, or download your converted text as a TXT or DOCX file once you’re done. File processing happens entirely in your browser, your file is never sent to a server.
How This Tool Works: The Logic Behind Every Conversion
Every case style on this page follows a clear, testable rule. Here’s what’s actually happening under the hood for each group of conversions.
Writing and Novelty Cases
lower case, UPPER CASE, aLtErNaTiNg, Inverse, Random, and Reverse Case are character-level transforms, each letter is mapped or reordered on its own, with no grammar involved. Upside Down text works the same way, using a Unicode character map so each letter has a visually flipped counterpart.
Programming and Naming Cases
camelCase, PascalCase, snake_case, kebab-case, dot.case, path/case, and the rest all start the same way: your text is broken into individual words using spaces, hyphens, underscores, and existing capital letters as boundaries. Those words are then rejoined using the target convention’s separator (underscore, hyphen, dot, slash, or none) and capitalization rule (first letter, every letter, or none).
This is why switching between naming conventions, say, moving from a requirements doc’s “maximum retry limit” to MAX_RETRY_LIMIT or maxRetryLimit, works cleanly even on messy, inconsistently formatted input.
Sentence Case and Title Case Use Grammar Rules, Not Just Punctuation
These two are the exception. Instead of a simple character map, they run through a grammar-aware engine that checks for abbreviations, acronyms, proper nouns, and punctuation context before deciding where a capital letter belongs. Full details and a live test sample are in the next section below.
The Stats Panel Uses the Same Engine as Our Word Counter
The Words, Characters, Sentences, and Paragraphs counts below the case buttons run on the exact same counting logic as our Word Counter tool, so the numbers stay consistent whichever tool you’re using:
- Words joined by a hyphen, such as well-being or follow-up, count as a single word, following standard editorial convention.
- A paragraph is counted each time two or more line breaks appear in sequence. A single line break does not start a new paragraph.
- Pressing Enter does not add to your character count. Only visible characters, letters, numbers, punctuation, and spaces, are counted.
- Common abbreviations like Dr., Mr., and Prof. are not counted as sentence endings even though they contain a period.
If you only need to check word or character counts without converting case, the standalone Word Counter gives you the same numbers plus reading time and Fleash readability level with a social media content length suggestions. Or, if you need to see the same counts from a PDF instead of plain text? Our PDF Word Counter extracts and counts it for you, no upload required.
Smart Sentence Case: Built to Handle Real-World Text
Most case converters treat Sentence case as “capitalize the first letter, lowercase the rest,” which breaks on real writing. This tool’s Sentence case is grammar-aware and correctly handles the edge cases that trip up simpler converters:
- Titles and abbreviations like Mr., Mrs., Dr., Prof., Jr., and Sr. are recognized and never mistaken for sentence endings.
- Acronyms such as NASA, CEO, HTML, and USA keep their correct capitalization instead of being flattened to lowercase.
- Country, city, and place names like Paris, United States, and Tokyo are automatically capitalized, even mid-sentence.
- Months and weekdays such as January and Monday are capitalized correctly wherever they appear.
- Time markers like a.m. and p.m. are kept in their correct lowercase form instead of being capitalized like a new sentence.
- URLs and email addresses are left untouched, example.com never becomes Example.Com, and the periods inside them are never mistaken for sentence breaks.
- Multiple punctuation marks, like “Really?!” or “Wait…”, are handled without adding extra capital letters or breaking sentences apart incorrectly.
- Contractions such as I’m, I’ve, I’ll, and I’d are capitalized correctly on the leading “I” without disturbing the rest of the word.
- Decimals and version numbers like 12.5% or v2.1.0 are never mistaken for sentence-ending periods.
- Text inside parentheses isn’t capitalized just because it follows an opening bracket, “the device (also known as the sensor) failed” keeps “also” lowercase mid-sentence.
- Ordinal numbers like 1st, 2nd, and 3rd are left untouched instead of being treated as sentence breaks.
Test the tool’s accuracy
mr. david chen and dr. sarah ahmed met in paris on monday at 9:00 a.m. to discuss the nasa project launching in july. the budget grew by 12.5% since version 2.1.0 shipped, e.g., the new html and css modules.
visit www.example.com or email sarah@example.com for details. prof. williams, the ceo, said “we’re ready!!” and i’m confident we’ll succeed.
mrs. henderson jr. agreed vs. the board’s concerns. will it work?? only time will tell.
This text includes abbreviations, an acronym, a country and city name, a weekday, a month, a time marker, a decimal, a version number, a URL, an email address, multiple punctuation, and contractions. Paste it into the tool above and click Sentence case to see how ToolPX handles every edge case correctly.
How to Use the Case Converter
- Add your text. Type or paste directly into the left panel, or upload an existing TXT or DOCX file to convert it instantly.
- Pick a case style. Choose from 20 options including lower case, UPPER CASE, Sentence case, Title Case, camelCase, snake_case, kebab-case, and more.
- Check your stats. The panel below updates live with Words, Characters, Sentences, and Paragraphs for your converted text.
- Reset anytime. Click Original to instantly restore your text exactly as you first typed or pasted it.
- Edit as needed. Use the toolbar to paste, copy, or clear your text.
- Export your work. Download the converted text as a TXT or DOCX file.
Frequently Asked Questions
What’s the difference between Sentence case and Title Case?
Sentence case capitalizes only the first word of each sentence (plus proper nouns and acronyms), the way a normal sentence is written. Title Case capitalizes the first letter of every major word, the format used for headlines and book titles.
How do I convert text to camelCase or snake_case?
Paste your text into the tool, then click camelCase or snake_case from the case style panel. The converter automatically detects word boundaries from spaces, hyphens, and existing capitalization, then rejoins the words using the correct format for that convention.
Does this tool store or upload my text?
No. Every conversion, including file uploads, runs locally in your browser. Your text is never sent to a server, stored, or logged, and no account is required to use the tool.
Why does Sentence case keep words like NASA or USA capitalized?
Most converters lowercase everything except the first letter of a sentence, which breaks acronyms. This tool recognizes common acronyms and abbreviations and preserves their capitalization instead of flattening them.
What’s the difference between Capital Case and Title Case?
Title Case follows standard headline capitalization rules, capitalizing major words while keeping short words like “of” or “the” lowercase. Capital Case capitalizes the first letter of every single word, with no exceptions.
How do I remove all capital letters from text?
Paste your text and click lower case. This converts every letter to lowercase regardless of the original formatting, useful for cleaning up text pasted from documents that used ALL CAPS or inconsistent capitalization.