Sentence Case Converter

About This Free Online Sentence Case Converter

Our free online Sentence Case Converter transforms your text to proper sentence case: the first letter of each sentence is capitalized while all other letters are lowercased. Unlike simple case converters, this tool intelligently detects sentence boundaries using punctuation marks (. ! ?) and preserves proper casing for the first word only. Perfect for fixing all-caps text, cleaning up messy copy, formatting article drafts, and preparing content for publication. All processing runs in your browser.

Features of Our Sentence Case Converter

Convert to proper sentence case
Intelligent sentence boundary detection
First letter of each sentence capitalized
Rest of text lowercased
Handles periods, exclamation marks, question marks
Real-time preview
100% private — browser-only processing

How to Use the Sentence Case Converter

Using this tool is simple and requires no signup or registration. Follow these steps:

Paste or type your text into the input area.
The text is automatically converted to sentence case.
Review the output to ensure proper sentence detection.
Copy the converted text.

Frequently Asked Questions About Sentence Case Converter

How does the tool detect sentence boundaries?

It detects sentences by looking for periods, exclamation marks, and question marks followed by a space or end of text.

Does it handle abbreviations?

Common abbreviations like "Dr." and "Mr." are handled to prevent false sentence breaks.

Why Choose Text Toolbox?

Text Toolbox provides free, private, and instant online text tools. Unlike other text utility websites that require signup accounts or send your data to servers, all our tools process your text entirely in your browser. This means your content never leaves your device — we cannot see it, store it, or share it. Our tools are fast, lightweight, and work on any device with a modern web browser.