Text Case ConverterFree online other calculator — instant results, no sign-up
Change text to uppercase or lowercase.
Sign in to save results and favorites.
About the Text Case Converter
The Text Case Converter changes the letters in your text to uppercase or lowercase using the selected Case option. Use it to capitalize all letters or make them all lowercase without rewriting the text. The default text, “Hello world. This is a sample.”, becomes “HELLO WORLD. THIS IS A SAMPLE.” when Uppercase is selected.
- Text
- The text to convert, defaulting to “Hello world. This is a sample.”, is a string with no measurement units.
- Case
- The conversion choice is Uppercase or Lowercase, defaults to Uppercase, and has no measurement units.
Formula and method
R = uppercase(T) if C = Uppercase; R = lowercase(T) if C = Lowercase. With the defaults: R = uppercase("Hello world. This is a sample.") = "HELLO WORLD. THIS IS A SAMPLE."- TThe input text.
- CThe selected Case option: Uppercase or Lowercase.
- RThe converted text displayed in the Text output row.
This tool performs a text transformation rather than an arithmetic calculation. It reads the input string, applies the uppercase or lowercase mapping selected by Case, and returns the transformed string. For the default inputs, lowercase letters become uppercase while existing capitals, spaces, and periods remain unchanged.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- TextHello world. This is a sample.
- CaseUppercase
Results
- TextHELLO WORLD. THIS IS A SAMPLE.
How to use the Text Case Converter
- 1Enter or paste the text into Text, or keep the default “Hello world. This is a sample.”.
- 2Choose Uppercase or Lowercase in Case; Uppercase is the default.
- 3Run the conversion using the selected case.
- 4Read the Text output row; with the default inputs, it shows “HELLO WORLD. THIS IS A SAMPLE.”.
Reading your result
The Text output row contains the converted string, not a count or numerical measurement. In the worked example, Text = HELLO WORLD. THIS IS A SAMPLE. means that the default sentence has been converted to uppercase, with its spaces and periods preserved.
Limitations
The converter changes letter case only; it does not correct spelling, rewrite sentences, or provide title case or sentence case. Digits, punctuation, and characters without case generally remain unchanged. Case mappings for accented letters and non-English scripts depend on the implementation’s Unicode and locale support; some mappings can change the number of characters. Do not assume that converting to the opposite case will restore the original capitalization.
Common questions
What does the default text produce with Uppercase selected?+
“Hello world. This is a sample.” becomes “HELLO WORLD. THIS IS A SAMPLE.”.
What happens if I select Lowercase for the default text?+
The result is “hello world. this is a sample.”, including lowercase letters at the start of both sentences.
Will uppercase conversion remove spaces or periods?+
No. Case conversion changes letters, so the spaces and periods in the default text remain in place.
Can I use Lowercase to undo an uppercase conversion?+
Lowercase makes all cased letters lowercase; it does not recover the original mix of capital and lowercase letters. Keep the original text if you need to preserve its capitalization.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
You might also like
Word Counter
Count whitespace-separated words.
Character Counter
Count Unicode code points with and without whitespace.
Sentence Counter
Estimate sentences using terminal punctuation.
Line Counter
Count logical lines, including a trailing empty line.
Text Reverser
Reverse the order of Unicode code points.
Text Palindrome Checker
Check a palindrome while ignoring punctuation and letter case.
Results are estimates for informational purposes and are not financial, medical or legal advice.