Case Converter Online
Convert case in one click: change small letters to capital letters, lowercase, title case, sentence case and more. Free, private, no signup.
Your text is processed in your browser and never uploaded. Dropped files: .txt, .md, .csv, .json or .html, up to 2 MB.
Writing styles
Developer styles
Quick answer: how to convert case online
To change text case online, paste your text into the box above, then click the style you want: UPPERCASE for capital letters, lowercase for small letters, Sentence case for normal writing, or Title Case for headlines. Copy the result or download it as a .txt file. It's free, needs no signup, and runs in your browser.
- Paste or type your text into the box.
- Click a case style, such as UPPERCASE or Title Case.
- Check the result. Click Undo if you want the old version back.
- Click Copy result or Download .txt.
Introduction
This case converter changes the capitalization of any text in one click. Paste a paragraph, a headline or a messy spreadsheet cell, and convert case to uppercase, lowercase, title case, sentence case and a handful of developer styles like camelCase and snake_case. It's the quick way to turn small letters into capital letters, or to fix a block of text that was typed with Caps Lock on.
Everything runs in your browser, so there's nothing to install and no account to make. You can undo any conversion, copy the result, or save it as a plain text file.
Why use this free online case converter
Plenty of pages offer to change case. Here's what's actually true about this one:
- Twelve styles on one page. Everyday styles (uppercase, lowercase, sentence, title) sit next to developer styles (camelCase, snake_case, kebab-case), so you don't bounce between tools.
- Undo that works. Each conversion is saved, and you can step back up to 50 conversions. A wrong click costs you nothing.
- No signup, no watermark, no word cap. Paste your text and go. Nothing is gated behind an account.
- Private by design. The conversion code runs in your browser. This page doesn't send your text anywhere.
- Handles real-world text. Accented letters, numbers, emoji and line breaks are preserved in the standard modes.
- Fast on any device. The page is small, uses your system font and makes no external requests.
How to convert case: step-by-step guide
Step 1: Add your text
Click inside the box and paste with Ctrl+V (Cmd+V on a Mac). You can also type directly, or drag a plain text file onto the box. If you'd rather browse for a file, click Choose a text file. The counter under the box shows characters, words and lines so you can confirm everything came through.
Step 2: Pick a case style
Click one of the buttons. The text in the box is replaced with the converted version straight away. Here's what each style does:
| Style | Example result | Best for |
|---|---|---|
| UPPERCASE | HELLO WORLD | Labels, warnings, and turning small letters into capital letters |
| lowercase | hello world | Normalizing messy text, tags, email addresses |
| Sentence case | Hello world. It's me. | Paragraphs, captions, text typed in Caps Lock |
| Capitalize Each Word | Hello World | Names, product lists, simple headings |
| Title Case | The Lord of the Rings | Headlines, article titles, book titles |
| aLtErNaTiNg | hElLo WoRlD | Jokes and social posts |
| iNVERSE | hELLO wORLD (from Hello World) | Swapping every letter's case at once |
| camelCase | helloWorld | JavaScript and Java variable names |
| PascalCase | HelloWorld | Class and component names |
| snake_case | hello_world | Python variables, database columns |
| kebab-case | hello-world | URL slugs, CSS class names |
| CONSTANT_CASE | HELLO_WORLD | Constants and environment variables |
Small to capital: how to change lowercase to uppercase
If you searched for "small to capital," the button you want is UPPERCASE. It turns every small letter into a capital letter and leaves digits, punctuation and spaces alone. Want only the first letter of each word capitalized? Use Capitalize Each Word. Want normal sentences with a capital at the start? Use Sentence case.
Step 3: Check the result and undo if needed
Read the converted text once. If a style isn't what you expected, click Undo and try another. You can also edit the text by hand in the box, which is handy for fixing names or acronyms after a conversion.
Step 4: Copy or download
Click Copy result to put the text on your clipboard, or Download .txt to save it as a file called case-converted.txt. Reset / Start over clears the box and the undo history.
Tips for best results
- Run a conversion on a short sample first if your text is long.
- Convert to Sentence case before Title Case if the source was all capitals. It makes the result easier to proofread.
- Need a word or character total as well? Our Word & Character Counter gives a fuller breakdown.
If you're curious how capitalization works in code, the MDN page on String.prototype.toUpperCase() explains the method this tool builds on.
Supported styles, file formats and limits
| Item | What this tool does |
|---|---|
| Typed or pasted text | No fixed limit. Your browser's memory is the ceiling. |
| Dropped or chosen files | .txt, .md, .csv, .json, .html and .htm, plus files your system labels as plain text. Maximum 2 MB. |
| File encoding | Read as text by your browser. UTF-8 files work best. |
| Output | Copy to clipboard, or download as a UTF-8 .txt file. |
| Undo history | The last 50 conversions in the current tab. Cleared on refresh or Reset. |
| Letters supported | Letters in any script that has upper and lower case, such as Latin, Greek and Cyrillic. Scripts without case, such as Chinese, pass through unchanged. |
| Title Case small words | a, an, and, as, at, but, by, for, in, nor, of, on, or, per, so, the, to, up, via, vs, yet stay lowercase unless first or last, or right after a colon, period, question mark or exclamation mark. |
| Not supported | Turkish dotted/dotless i rules, automatic detection of names and acronyms, and style-guide-specific title rules (AP, APA, Chicago). |
Who uses a case converter: practical use cases
- Students: fix an essay heading typed in all caps, or format a bibliography entry's title.
- Bloggers and editors: turn a draft headline into proper Title Case before publishing.
- Social media managers: tidy captions that arrived in the wrong case from a client's spreadsheet.
- Developers: rename a phrase into camelCase for a variable, snake_case for a database column or kebab-case for a URL slug.
- Data entry and office staff: normalize a column of names or product codes before importing. If the list also has repeats, run it through Remove Duplicate Lines afterward.
- Customer support teams: rescue a customer's all-caps message into readable sentences before pasting it into a ticket.
- Writers and translators: reset text copied from a PDF or a legacy system that forced capitals.
Key features and benefits
- Twelve case styles in two clear groups.
- One-click conversion in the same box, so there's no separate output to hunt for.
- Undo for up to 50 conversions.
- Drag-and-drop or file picker for text files up to 2 MB.
- Live character, word and line counts.
- Copy to clipboard and download as .txt.
- Keyboard accessible, with visible focus outlines, labeled controls and large tap targets.
- Light theme with automatic dark mode.
- Friendly error messages for empty input, wrong file types and oversized files.
- No signup, no watermark, no ads inside the tool.
Expert tips and common mistakes
Title Case and Sentence case lowercase everything first
Both modes lowercase the whole text before capitalizing, which keeps results predictable. The catch: acronyms and proper nouns lose their capitals. "NASA" becomes "Nasa" and "London" becomes "London" only when it starts a sentence. After converting, scan for names, brands and acronyms and fix them by hand.
Title case rules vary by style guide
AP, Chicago and APA don't agree on every small word or on words of four letters like "with" and "from." This tool uses one common, simple rule, listed in the table above. If a publisher requires a specific guide, treat the output as a strong first draft and check it.
Don't use all caps for long text
UPPERCASE is fine for a short label or warning. For whole paragraphs it's harder to read, and many people read all caps in emails or messages as shouting. Sentence case is almost always the better choice for anything longer than a line.
Mind the separators in developer styles
camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE split your text into words first. They treat spaces, punctuation and underscores as boundaries, and they also split inside existing camelCase, so "XMLHttpRequest" becomes "xml_http_request" in snake_case. Characters that aren't letters or digits are dropped, and each line is converted on its own.
Watch line breaks when pasting from PDFs
Text copied from a PDF often has hard line breaks in the middle of sentences. Sentence case treats a line break as a possible sentence start, so it may capitalize the first word of each broken line. Remove the extra breaks first, or compare before and after with the Text Diff Checker.
Keep an original copy
Undo history disappears when you refresh the tab. If the text matters, keep the source somewhere else before you convert it.
Privacy and security
Your text is processed in your browser and is never uploaded. The conversion is plain JavaScript running on your device. The page loads no external scripts, fonts or images, and it makes no network requests while you convert text. Nothing is saved to cookies or local storage by the tool, so closing or refreshing the tab clears your text and your undo history.
A few honest notes. Your browser or a clipboard manager on your device may keep a copy of anything you copy or paste, and that's outside this page's control. If you're on a shared or public computer, avoid pasting passwords, banking details or other secrets into any web page, this one included. Standard analytics or hosting logs may record that the page was visited, but they don't see what you type into the box.
This case converter vs. alternatives
Every approach has a place. Here's a fair look at the common options:
| Factor | This browser tool | Word processors | Code editors | Server-based sites |
|---|---|---|---|---|
| Setup | None, just open the page | Needs the app or an account | Needs an editor, sometimes an extension | None |
| Where text is processed | On your device | On your device or in the cloud | On your device | Varies by site |
| Everyday styles (upper, lower, title) | Yes | Yes, usually built in | Usually | Yes |
| Developer styles (snake_case and others) | Yes | Rarely | Often via commands or extensions | Varies |
| Undo after converting | Up to 50 steps in the tab | Yes | Yes | Varies |
| Cost | Free | Often a paid suite or a free account | Often free | Often free with ads |
If you're already working inside Word or Google Docs on a long document, their built-in capitalization options are convenient. This page is faster when you just have a snippet to fix, need a developer style, or want to avoid opening a big app. And if you want stylized letters rather than a case change, try the Fancy Text Generator.
Troubleshooting
A button does nothing or shows "Type or paste some text first"
The box is empty or only contains spaces. Paste your text and click again.
"Nothing to change" appears
Your text already matches that style, so there's nothing to convert. Try a different style, or edit the text and click again.
Acronyms and names lost their capitals
Title Case, Sentence case and Capitalize Each Word lowercase the text before capitalizing. Retype the capitals for names, brands and acronyms afterward, or click Undo and capitalize only the parts you need.
Copy result doesn't work
Some browsers block clipboard access in certain settings, such as embedded views. The tool tries a fallback, but if it still fails, click inside the box, press Ctrl+A (Cmd+A on a Mac), and copy with the keyboard.
My file won't load
Check three things: the file is 2 MB or smaller, it's a plain text type (.txt, .md, .csv, .json or .html), and it isn't a Word, PDF or image file renamed to .txt. For Word or PDF content, copy the text out and paste it into the box.
Strange characters appear after loading a file
The file probably isn't saved as UTF-8. Open it in a text editor, save it again with UTF-8 encoding, and reload it here.
The German ß turned into SS, or Turkish i looks wrong
That's standard JavaScript uppercase behavior. It follows general Unicode rules and doesn't apply language-specific Turkish handling. For Turkish text, check the letters i and ı after converting and fix them by hand.
Undo doesn't go back far enough
The tool keeps the last 50 conversions in the current tab. Refreshing the page or clicking Reset clears them. Keep a copy of the original text if you need a permanent fallback.
Glossary
- Uppercase
- Capital letters, such as A, B and C. Also called majuscule or "caps."
- Lowercase
- Small letters, such as a, b and c. Also called minuscule.
- Sentence case
- Capitalizing only the first word of a sentence, the pronoun I, and proper nouns.
- Title case
- Capitalizing the major words of a title while keeping short articles, conjunctions and prepositions lowercase.
- camelCase
- Words joined with no spaces, where each word after the first starts with a capital, like
userName. - PascalCase
- Like camelCase, but the first word is capitalized too, like
UserName. - snake_case
- Lowercase words joined with underscores, like
user_name. - kebab-case
- Lowercase words joined with hyphens, like
user-name. - Unicode
- The standard that assigns a code to letters and symbols from nearly every writing system, including their upper and lower case forms. For background, see the Wikipedia article on letter case.
Frequently asked questions
Is this case converter really free?
Yes. The case converter is completely free, with no trial period, no plan-based word cap and no watermark. You can convert as much text as your browser can handle, as often as you like, without creating an account or entering an email address.
Is it safe to paste private text into it?
Yes. Conversion runs in your browser with JavaScript, and this page never sends your text to a server. Nothing is stored after you close or refresh the tab. Even so, avoid pasting passwords or other secrets into any web page on a shared computer.
Do I need to sign up or install anything?
No. There is no signup, no login and no download. Open the page, paste your text, click a case button and copy the result. It should work in current versions of Chrome, Safari, Firefox and Edge on desktop, tablet and phone.
How do I change small letters to capital letters?
Paste your text and click UPPERCASE to turn every small letter into a capital letter. If you only want the first letter of each word capitalized, click Capitalize Each Word. For normal sentences, click Sentence case. Each button works instantly, and you can undo it.
What is the difference between title case and sentence case?
Sentence case capitalizes only the first word of each sentence and the pronoun I, like normal writing. Title case capitalizes the main words in a headline and keeps short words such as a, the, of and in lowercase unless they start or end the title.
Is there a limit on how much text I can convert?
You can paste or type as much as your browser comfortably handles. Dropped text files are limited to 2 MB, which is roughly two million plain English characters. Very large inputs may feel slower on older phones, but the conversion itself is a single quick pass.
Does it work on my phone?
Yes. The layout is built for small screens first, buttons are at least 44 pixels tall, and the text box resizes to fit. Use your phone's normal paste and copy gestures, or tap the Copy result button to put the converted text on your clipboard.
Will converting case change my words or punctuation?
No. The standard modes only change letter case. Spelling, punctuation, numbers, emoji and line breaks stay as they are. The exceptions are the code-style modes such as snake_case and kebab-case, which intentionally replace spaces and symbols with separators.
Does it work offline?
Once the page has loaded, the conversion code needs no internet connection, so it keeps working if your connection drops. You do need to be online to open the page the first time. The tool does not install itself as an offline app.
Can it handle accented letters like é or ü?
Yes. Accented Latin letters convert correctly between upper and lower case. Note that German ß becomes SS in uppercase, which is standard JavaScript behavior. The tool doesn't apply special Turkish rules for the dotted and dotless letter i.
Convert your text now
You don't need a word processor or a signup to fix capitalization. Paste your text into this free online case converter, click a style, and copy the result in seconds. If you picked the wrong style, Undo is one click away. Scroll back up to the tool and convert case on your own text right now. Then try one of the related tools below for the next step.
Related tools
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