Text Case Converter
Paste your text, select a case — converts instantly
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Text Case Converter — Free Online Case Changer

Text case conversion - Text case converter

You typed an entire paragraph with Caps Lock on by mistake. Or you need a heading in title case before publishing. Or you are a developer who needs snake_case variable names from plain English labels. Whatever the reason — this free text case converter changes your text instantly. The tool covers nine conversion modes from basic UPPERCASE and lowercase to developer-friendly camelCase and snake_case.
Paste your text, select a case and the result appears on the right immediately. Nine conversion modes, no button to press, no page to reload.

How to Fix Accidental Caps Lock Typing

Accidentally typed a whole paragraph with Caps Lock on? This is the most common reason people search for a text case converter — and the fastest fix.

Before:

i WAS TYPING THIS EMAIL AND DID NOT REALISE MY CAPS LOCK WAS ON THE WHOLE TIME.

After — Inverse Case:

I was typing this email and did not realise my caps lock was on the whole time.

Paste your text into the text case converter → click iNVERSE cASE → copy the result. Done in three seconds. Inverse case flips every letter to its opposite — uppercase becomes lowercase and lowercase becomes uppercase — correcting the mistake without retyping a single word.

Title Case Rules — What Gets Capitalised

Title case is more nuanced than capitalising every word. The standard rules are:
Always capitalise:

  • The first and last word of the title
  • Nouns, verbs, adjectives and adverbs
  • Words of four or more letters

Do not capitalise:

  • Articles: a, an, the
  • Short prepositions: at, by, for, in, of, on, to, up
  • Short conjunctions: and, but, or, nor

Examples:

  • “The Quick Brown Fox Jumps over the Lazy Dog”
  • “How to Write a Blog Post That Ranks on Google”
  • “A Guide to Title Case for Writers and Editors”

This text case converter follows these rules automatically — small connecting words stay lowercase while every meaningful word is correctly capitalised.

camelCase and snake_case — For Developers

Two of the nine conversion modes are built specifically for developers:
camelCase is the standard naming convention in JavaScript, Java and Swift. It removes spaces and capitalises the first letter of each word except the first:

firstName, getUserData, calculateTotalPrice

snake_case is the standard in Python, Ruby and SQL databases. It replaces spaces with underscores and uses all lowercase:

first_name, get_user_data, calculate_total_price

Paste a list of plain English labels — “First Name”, “Last Name”, “Total Price” — select the convention you need and get developer-ready names instantly.

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Frequently Asked Questions

Paste the accidentally capitalised text into the text case converter and click iNVERSE cASE. This flips every letter — uppercase becomes lowercase and lowercase becomes uppercase — correcting the caps lock mistake in one click without retyping anything.

Title Case capitalises the first letter of every important word and is used for headings and titles. Sentence case capitalises only the first letter of each sentence and is used for body text and normal writing. “The Quick Brown Fox Jumps over the Lazy Dog” is Title Case. “The quick brown fox jumps over the lazy dog” is Sentence case.

Alternating case switches between lowercase and uppercase letter by letter — “Hello World” becomes “hElLo wOrLd”. It is associated with the mocking SpongeBob internet meme and used for sarcastic or comedic effect on social media.

camelCase is a naming convention in programming — particularly JavaScript, Java and Swift. It removes spaces and capitalises the first letter of each word except the first. Variable names like firstName, totalPrice and getUserData are all camelCase.

snake_case is the naming convention in Python, Ruby and SQL. It replaces spaces with underscores and uses all lowercase. Column and variable names like first_name, total_price and user_id are all snake_case.

No — all conversion happens entirely in your browser. Your text is never sent to our servers, stored or shared with anyone. Close the tab and it is gone completely.

Inverse Case flips every letter based on its current state — uppercase becomes lowercase and lowercase becomes uppercase. Alternating Case ignores the current state and simply switches between lower and upper in a fixed pattern starting from the first letter.

About This Text Case Converter

This text case converter is part of CalcDaysTime — a free suite of date, time and maths tools built for students, writers, developers and anyone who works with text. All nine conversion modes run entirely in your browser. Your text is never sent to our servers, stored or shared with anyone. There is no character limit — paste an entire document and the conversion happens instantly.

Disclaimer: Results are based on standard English case conversion rules. Title Case follows the AP and Chicago style guidelines for small words. camelCase and snake_case conversions remove special characters and punctuation — always review output before using in code.