Case Converter

Ten casing conventions, applied without destroying your original text.

Runs in your browser. Nothing you enter here is uploaded to a server.

How to use the case converter

Step 1: Paste your text
The original is preserved in its own field and is not modified by any conversion.
Step 2: Choose a case
Each option shows a live preview of the result, so you can see what a convention does before committing to it.
Step 3: Set the locale if it matters
Defaults to your browser locale. Change it when converting Turkish, Azerbaijani, Lithuanian or German text, where casing rules differ from the default.
Step 4: Copy or download the result
Copy to the clipboard or save the converted text as a file. The original remains untouched either way.

Worked example

One phrase in every convention

Starting from: user profile image URL

lowercase: user profile image url
UPPERCASE: USER PROFILE IMAGE URL
Sentence case: User profile image url
Title Case: User Profile Image URL
camelCase: userProfileImageUrl
PascalCase: UserProfileImageUrl
snake_case: user_profile_image_url
kebab-case: user-profile-image-url
CONSTANT_CASE: USER_PROFILE_IMAGE_URL

The programming conventions collapse whitespace and punctuation into a single separator, which is why they are safe for identifiers and filenames but lossy for prose.

How each conversion works

Prose conversions change letter casing and leave the structure alone. Identifier conversions first split the text into words at spaces, punctuation and existing case boundaries, then rejoin them with the target separator.

lowercase / UPPERCASE   locale-aware casing, structure untouched
Sentence case           first letter of each sentence capitalised
Title Case              each word capitalised, minor words lowercased
camelCase               words joined, first word lowercase
PascalCase              words joined, every word capitalised
snake_case              words joined with underscores, lowercased
kebab-case              words joined with hyphens, lowercased
CONSTANT_CASE           words joined with underscores, uppercased
alternating case        letters alternate, non-letters skipped

Alternating case is deterministic: it starts lowercase and only advances the alternation on letters, so the same input always produces the same output regardless of punctuation.
Locale selection matters more than it looks. In Turkish, uppercasing "i" gives "İ" rather than "I", and the default locale gets that wrong.
Digits and emoji pass through the identifier conversions unchanged, and are treated as word boundaries where that is the sensible reading.

Limitations and privacy

What this tool does not do

Title Case uses a documented list of minor words. It cannot know that a particular word is a proper noun, a brand name or part of a quoted title, so editorial review is still needed.
Sentence case relies on sentence detection, which can be fooled by abbreviations like "Dr." or "e.g." and by decimal points inside numbers.
The identifier conversions are lossy. Converting to snake_case and back will not restore the original punctuation or capitalisation.
Acronyms are handled by convention rather than knowledge: "URL" becomes "Url" in PascalCase, which some style guides prefer and others do not.

All conversion happens in your browser. Neither the original nor the converted text is uploaded, stored or logged.

Frequently asked questions

What is the difference between Title Case and Sentence case?

Title Case capitalises most words in a heading, leaving short articles, conjunctions and prepositions lowercase unless they start or end the title. Sentence case capitalises only the first word of each sentence, plus any proper nouns that were already capitalised.

When should I use camelCase rather than snake_case?

It is a convention, not a rule, and it follows the language. JavaScript, Java and C# lean camelCase and PascalCase; Python, Ruby and SQL lean snake_case; CSS classes and URL slugs use kebab-case. Match whatever the surrounding code already does.

Why does the locale setting matter?

Because casing is language-specific. The best-known example is Turkish, where lowercase "i" uppercases to "İ" and the dotless "ı" uppercases to "I". Using the wrong locale there produces a different word, not just different styling.

Will converting my text lose anything?

The prose conversions preserve everything except letter casing. The identifier conversions deliberately discard spacing and punctuation, so they are lossy — which is why the original text stays on screen next to the result.

How does alternating case treat punctuation and numbers?

It skips them. The alternation only advances on letters, so a space or a comma does not flip the pattern. This makes the output deterministic and repeatable, which a naive position-based implementation is not.

Other tools people use alongside the case converter.

Word Counter
Count words, sentences and paragraphs as you type, with reading time, speaking time and the most frequent keywords in your text.
Character Counter
Count characters the way people see them and the way software measures them, with UTF-8 byte size, line counts and a character limit tracker.
UUID Generator
Generate up to 100 random version 4 UUIDs at once, with optional uppercase, braces or no hyphens. Copy them all or download them as a text file.
QR Code Generator
Create QR codes for links, text, email, phone, SMS and Wi-Fi networks. Download as PNG or SVG. Encoding happens in your browser, not on a server.

Part of Text & Developer Tools. Last reviewed 16 September 2026.