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Case Converter

Change the letter case and naming style of text without uploading it. Choose a format, review the result, then copy or download it.

New to text case? Read the step-by-step guide

Private text conversion

Convert letter case

Choose a mode, enter text, and pause briefly while the local result updates.

500,000 character limit

Conversion mode

Lowercases other letters, then capitalises the beginning of each detected sentence.

Advanced settings

A locale helps the browser apply language-sensitive uppercase and lowercase rules.

Enter a BCP 47 language tag, or leave empty to use the browser locale.

Browser locale will be used.

Line breaks are preserved. Text is not stored.

0 input characters

Read-only until you copy, download, or reuse it.

0 output characters

Add text to begin converting.

One input, several results

See what each family of modes changes

the quick brown fox builds useful web tools
Sentence case
The quick brown fox builds useful web tools
UPPERCASE
THE QUICK BROWN FOX BUILDS USEFUL WEB TOOLS
camelCase
theQuickBrownFoxBuildsUsefulWebTools
snake_case
the_quick_brown_fox_builds_useful_web_tools
kebab-case
the-quick-brown-fox-builds-useful-web-tools
Honest limits

Case conversion changes form, not meaning

  • Title casing differs by language, publisher, and style guide.
  • Case conversion does not rewrite grammar or correct spelling.
  • Acronym detection in English title case is an approximation.
  • Some writing systems do not distinguish uppercase and lowercase.
  • Developer modes treat punctuation as a separator and may remove it.
  • Foxger does not save the entered or converted text.
Learn the formats

Choose a mode with confidence

The beginner guide explains capital and small letters, natural-language modes, developer naming styles, locale limits, and every action in the workbench.

New to text case? Read the step-by-step guide
Step-by-step guide

See what case conversion changes

You have the right words, but they need to fit a sentence, heading, label, or code-style name. Start with one input, then compare what each mode changes.

Back to the Case Converter
Beginner guide contents
Start here

Letter case in one minute

Here is the guide’s example in three different forms:

Input:
the quick brown fox builds useful web tools

lowercase:
the quick brown fox builds useful web tools

snake_case:
the_quick_brown_fox_builds_useful_web_tools

camelCase:
theQuickBrownFoxBuildsUsefulWebTools

The words stay in the same order. lowercase keeps ordinary spaces,snake_case replaces them with underscores, and camelCase removes separators while capitals mark later words.

Letter case is the difference between capital and small forms such as F andf. Foxger changes that representation and, in developer modes, the separators. It does not decide whether the words are correct.

Choose the right task

Do you need this tool?

Use the converter when the words are correct but their letter or naming style needs to change.

It may help with

  • repairing text typed with Caps Lock;
  • preparing a heading or list;
  • making variable or file-name ideas;
  • changing copied labels to one consistent style;
  • trying locale-aware uppercase or lowercase.

Choose another approach for

  • rewriting grammar or spelling;
  • translating between languages;
  • checking facts or meaning;
  • following a publisher’s detailed title guide;
  • transliterating one writing system into another.
Reading and writing cases

Uppercase and lowercase

lowercase changes every letter with a small form to that form. UPPERCASE changes every letter with a capital form to that form. Spaces, numbers, emoji, punctuation, and line breaks remain where they are.

Foxger Builds 4 Tools.
foxger builds 4 tools.
FOXGER BUILDS 4 TOOLS.

tOGGLE cASE belongs to this family too: it swaps each capital and small letter. It can repair text typed with reversed Caps Lock.

Uppercase can suit a short label, but a long uppercase paragraph can be harder to read. Lowercase can provide a uniform starting point before another transformation.

Natural writing

Sentence case

Sentence case lowercases the text, then capitalises the first cased letter at a detected sentence or line beginning. Punctuation and blank lines remain where practical.

tHE FOX BUILDS TOOLS. tHE TOOLS RUN LOCALLY.
The fox builds tools. The tools run locally.

Sentence detection uses the browser’s locale-sensitive boundaries when available, with a local approximation for older browsers. Abbreviations and unusual punctuation can still produce a result that needs review.

Word beginnings

Capitalise each word

Capitalize Each Word lowercases other cased letters and changes the first cased letter of each word to uppercase. It keeps ordinary punctuation between words.

notes from the foxger workshop
Notes From The Foxger Workshop

This mode can suit labels or short lists. It capitalises small connecting words such as the and from, so it is different from English title case.

Editorial approximation

English title case

Title Case — English capitalises the first and last word. Between them, it lowercases a restrained list of common short words such as a, and, for, of, the, and to. Other words receive an initial capital.

a guide to tools for the browser
A Guide to Tools for the Browser

Foxger preserves a short all-capital word as an acronym only when the input gives a strong clue, such as an API for local tools. This remains an approximation rather than compliance with every editorial style.

Names without ordinary spaces

Developer naming cases

The next six modes rebuild words as code- or file-style names. Foxger treats spaces, punctuation, underscores, and hyphens as boundaries, processes each non-empty line independently, and does not transliterate the words.

camelCase

Begins with a lowercase word, then capitalises each later word.

foxgerBrowserTool

PascalCase

Capitalises every word and removes separators.

FoxgerBrowserTool

snake_case

Uses lowercase words separated by underscores.

foxger_browser_tool

kebab-case

Uses lowercase words separated by hyphens.

foxger-browser-tool

CONSTANT_CASE

Uses uppercase words separated by underscores.

FOXGER_BROWSER_TOOL

dot.case

Uses lowercase words separated by full stops.

foxger.browser.tool

The converter also recognises common boundaries inside existing names, so browserTool can become browser_tool. A programming language or team may have extra rules for allowed characters, reserved words, or identifier length.

Read the workbench

Understand every control

Each visible field and action has one role.

Letter or naming style

Selects one of the twelve modes. The explanation below the menu changes with the selection.

Text to convert

Holds the original input. It stays in place until you replace it, use Clear, or leave the page.

Converted text

Shows a read-only result. Foxger writes through the textarea value, so entered markup remains text.

Locale

Accepts an optional BCP 47 tag such as en, tr, de, or fr. Foxger shows the resolved or fallback locale.

Character counts

Report Unicode code points in the current input and output. The processing limit protects ordinary browser-sized work.

Copy

Sends the converted result to the clipboard after you select the button. If clipboard access is unavailable, Foxger selects the output for manual copying.

Download

Creates a UTF-8 text Blob locally and asks the browser to download foxger-case-converted.txt.

Use output as input

Replaces the input only after you select it. This can help when applying a second transformation.

Load example

Loads the guide’s fox sentence, selects Sentence case, and uses the browser locale.

Clear

Removes both text values and returns the mode and locale fields to their defaults.

One example throughout

Complete example

The workbench and this guide use the same input:

the quick brown fox builds useful web tools
Sentence caseThe quick brown fox builds useful web tools
UPPERCASETHE QUICK BROWN FOX BUILDS USEFUL WEB TOOLS
camelCasetheQuickBrownFoxBuildsUsefulWebTools
snake_casethe_quick_brown_fox_builds_useful_web_tools
kebab-casethe-quick-brown-fox-builds-useful-web-tools

These results match the live implementation. They change the same words’ representation, not their meaning. A developer-style result suits an identifier rather than ordinary prose; after separators or punctuation are removed, another conversion may not restore the exact original.

Select Load example, then move through the mode menu to compare the results in the output textarea.

Follow along

Step-by-step walkthrough

Use these steps with the complete example or your own text.

  1. Choose the text

    Use the sentence, heading, list, variable name, or other plain text whose case you want to change. Keep a separate copy when the original matters.

  2. Paste or type it in the input

    Place the text in “Text to convert.” Foxger keeps it there while you try modes and does not submit a form.

  3. Choose one conversion mode

    Select Sentence case for the guide example. The output refreshes shortly after you pause typing or change the selection.

  4. Review punctuation and line breaks

    Natural-language modes keep punctuation where practical. Developer modes use punctuation as a boundary, so compare the result with the input.

  5. Set a locale when it matters

    Open Advanced settings and enter a language tag such as tr for Turkish. Leave it empty when the browser locale is suitable.

  6. Try another mode

    Choose camelCase, snake_case, or another format. Empty lines stay between independently converted developer-name lines.

  7. Copy or download the reviewed result

    Copy uses the clipboard. Download creates a local UTF-8 file named foxger-case-converted.txt. Neither action uploads the text.

  8. Reuse or clear deliberately

    Use output as input only when you want to transform the result again. Clear removes the text after you select it.

Back to the Case Converter

Match format to purpose

Choosing the right mode

Begin with the kind of text you are preparing, then review any rules from its destination.

Ordinary prose

Try Sentence case, then repair names, acronyms, and any sentence boundary the browser interpreted differently.

Short labels

Capitalize Each Word can suit labels. UPPERCASE may suit a brief warning or code already specified that way.

English headings

Try Title Case — English when an editorial approximation is useful, then compare it with the required style guide.

Program identifiers

Choose the convention required by the language or project: camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, or dot.case.

Reversed Caps Lock

tOGGLE cASE swaps cased letters. It is useful when uppercase and lowercase are consistently reversed.

Uniform source text

lowercase or UPPERCASE can provide one consistent form before copying the result into another controlled process.

Language-sensitive details

Language and locale limitations

A locale is a language tag used by built-in browser internationalisation APIs. For example, en means English and tr means Turkish. A region can follow, as in en-GB. Use hyphens rather than underscores in a BCP 47 locale.

Locale matters because case pairs are not identical across languages. Turkish distinguishes dotted i and dotless ı. German uppercase can expand ß to SS in many browser operations. Browser versions can also differ.

Unicode allows Foxger to retain letters from many writing systems. It does not transliterate them into Latin letters. Some scripts, including commonly used forms of Chinese and Japanese, do not have an uppercase/lowercase distinction, so a natural case mode may not change them.

Avoid surprises

Common mistakes

  • Using title case for a sentenceSentence case normally capitalises the sentence beginning; title case changes several words.
  • Expecting grammar repairCase conversion changes letter form. It does not rewrite wording, punctuation, facts, or grammar.
  • Treating every title guide as identicalA school, publisher, or workplace may use a different list of short words and special cases.
  • Forgetting punctuation in developer modesIdentifier modes treat punctuation as separators and may remove symbols that carried meaning.
  • Choosing the wrong localeLanguage-sensitive letters can produce a different result under another locale, especially dotted and dotless i.
  • Assuming every script has two casesMany scripts have no uppercase and lowercase distinction, so their letters can remain unchanged.
  • Converting the only copyKeep important original text outside the tool before using the output in another document.
  • Reading an unchanged result as an errorNumbers, emoji, punctuation, and scripts without case distinctions may stay the same.
When a result surprises you

Troubleshooting

The output does not update

Pause briefly after typing. Confirm JavaScript is enabled and reload if the workbench remains inactive. The guide stays readable without JavaScript.

The locale is rejected

Enter a BCP 47 tag such as en, tr, or en-GB. Foxger shows which fallback locale it used for a malformed or unsupported value.

A name lost its capital letter

Sentence and word modes cannot identify every proper name. Restore names and acronyms after reviewing the result.

Punctuation disappeared

Developer naming modes treat punctuation as a separator. Choose a natural-language mode when the punctuation must remain.

Some letters did not change

The script may have no case distinction, or the characters may be numbers, symbols, marks, or emoji. Foxger keeps those characters where the selected mode permits.

Conversion paused for a large input

The hard limit is 500,000 characters. Your input remains in the textarea. Shorten it or use Clear to resume conversion.

Words used in this guide

Glossary

Capital letter
An uppercase form such as A, B, or C in writing systems that distinguish letter case.
Small letter
A lowercase form such as a, b, or c in writing systems that distinguish letter case.
Word
A group of letters or numbers treated as one unit for the selected conversion.
Sentence
A unit of writing that expresses an idea and commonly begins with a capital letter.
camelCase
A naming style that begins with a lowercase word and capitalises each following word without separators.
PascalCase
A naming style that capitalises every word and joins them without separators.
snake_case
Lowercase words joined by underscores.
kebab-case
Lowercase words joined by hyphens.
CONSTANT_CASE
Uppercase words joined by underscores.
dot.case
Lowercase words joined by full stops.
Locale
A language tag, sometimes with script or region details, that helps software apply language-sensitive rules.
Unicode
A standard for representing text from many languages, writing systems, symbols, and emoji.
Try it yourself

Practice exercise

Convert a short project phrase

Enter my helpful science project, then work through these tasks:

  1. Create Sentence case for an ordinary sentence beginning.
  2. Create Title Case — English for a heading.
  3. Create camelCase for a variable idea.
  4. Create snake_case for a name that uses underscores.
  5. Add — 2026! and notice what the developer modes keep or remove.
Show sample results

My helpful science project

My Helpful Science Project

myHelpfulScienceProject

my_helpful_science_project

Before using the result

Final checklist

  • I chose a mode that matches prose, a heading, a label, or a developer naming rule.
  • I reviewed names, acronyms, punctuation, and line breaks.
  • I checked the required title style instead of treating the approximation as a rulebook.
  • I selected a useful locale or accepted the browser locale.
  • I understand that some scripts have no letter-case distinction.
  • I kept an original copy when the text matters.
  • I know case conversion does not repair grammar, spelling, facts, or meaning.
  • I know Foxger does not upload or save the text.
Back to the Case Converter
Common questions

Case Converter FAQ

Which case formats can Foxger create?

Foxger provides lowercase, UPPERCASE, Sentence case, Capitalize Each Word, Title Case — English, tOGGLE cASE, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and dot.case.

Is English title case exact for every style guide?

No. Foxger uses an editorial approximation that capitalises the first and last word and lowercases a restrained list of common short words between them. Publishers and style guides can use different rules.

What does the optional locale change?

A locale gives the browser language information for uppercase and lowercase conversion. It matters for cases such as Turkish dotted and dotless i. Leave the field empty to use the browser locale.

What happens to punctuation in developer naming modes?

camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and dot.case treat punctuation, spaces, underscores, and hyphens as word separators. Those separators are replaced by the selected naming pattern.

Does Case Converter preserve multiple lines?

Yes. Natural-language modes preserve line breaks. Developer naming modes process each non-empty line independently and preserve the line breaks between those results.

Will Foxger transliterate non-Latin writing?

No. Foxger keeps Unicode letters and numbers in their original script. Some scripts do not distinguish uppercase from lowercase, so a case change may leave those characters unchanged.

Is my text uploaded or saved?

No. Conversion runs locally in your browser. Foxger does not upload the text, place it in the page URL, or store it in local storage, session storage, cookies, or a database.

What happens when the input is very large?

Foxger warns at 100,000 characters and pauses conversion above 500,000 characters to protect the browser tab. The complete input remains in the textarea so you can shorten or clear it.

Back to the Case Converter

Optional support

Help keep Foxger useful

Foxger tools are free, private, and built without display ads. Optional support helps keep them maintained, tested, and documented.

Support Foxger
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