Text Tools
Sentence Case Converter
Convert text to sentence case automatically. Capitalize the first letter of each sentence and lowercase the rest with our free sentence case converter tool.
Use Sentence Case Converter to get instant results without uploads or sign-ups. Everything runs securely in your browser for fast, reliable output.
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About this tool
Convert text to proper sentence case with our free online sentence case converter. Automatically capitalize only the first letter of each sentence while making all other letters lowercase, following standard English capitalization rules. Perfect for fixing text that's all uppercase or all lowercase, formatting copied text, correcting accidental caps lock typing, preparing text for formal documents, or ensuring consistent sentence capitalization throughout your content.
Our sentence case converter intelligently identifies sentence boundaries based on punctuation marks (periods, question marks, exclamation points) and capitalizes the first letter after each. The tool handles multiple sentences, paragraphs, and various punctuation scenarios. Optional "Preserve Proper Nouns" setting can attempt to maintain capitalization of already-capitalized words that might be names or proper nouns.
Essential for content writers fixing formatting issues, students correcting essay capitalization, email writers fixing caps lock mistakes, social media managers formatting posts properly, data entry professionals cleaning up text data, and anyone needing to convert text to standard sentence case quickly. The tool processes text of any length instantly.
All conversion happens locally in your browser - your text stays completely private with no server uploads. No registration required, no character limits, works on all devices including mobile, and functions offline. Free to use unlimited times for all your text formatting needs.
Usage examples
Fix All-Caps Text
Input: "THIS IS MY TEXT. IT WAS TYPED IN ALL CAPS. HOW DO I FIX IT?"
Output: "This is my text. It was typed in all caps. How do i fix it?" (Each sentence starts with capital, rest lowercase)
Fix All-Lowercase Text
Input: "hello there. how are you doing? i am fine."
Output: "Hello there. How are you doing? I am fine." (First letter of each sentence capitalized)
Multiple Sentence Types
Input: "WHAT TIME IS IT? IT IS 3PM. GREAT!"
Output: "What time is it? It is 3pm. Great!" (Works with periods, question marks, and exclamation points)
Paragraph Text
Input: "first sentence here. second one follows. third sentence ends it."
Output: "First sentence here. Second one follows. Third sentence ends it." (Handles continuous text with multiple sentences)
Mixed Case Input
Input: "tHiS iS WeIrD tExT. iT nEeDs fIxInG."
Output: "This is weird text. It needs fixing." (Normalizes any mixed or alternating case)
How to use
- Paste or type your text into the text area
- Text can be in any case: UPPERCASE, lowercase, or mixed
- Optionally preserve proper nouns if already capitalized
- Click "Run Tool" to convert to sentence case
- View text with proper sentence capitalization
- Copy the formatted text with one click
Benefits
- Instant sentence case conversion
- Automatically detects sentence boundaries
- Handles periods, question marks, and exclamation points
- Works with paragraphs and multiple sentences
- Optional proper noun preservation
- Fixes all-caps or all-lowercase text
- No character limit - process large documents
- Maintains original punctuation and spacing
- One-click copy functionality
- No registration required
- Complete privacy - browser-based
- Mobile-friendly interface
- Free forever with unlimited use
- Works offline after first load
FAQs
What is sentence case and when should I use it?
Sentence case capitalizes only the first letter of each sentence and proper nouns, making the rest lowercase. It's the standard capitalization for normal prose, paragraphs, and body text in most writing. Use it for essays, articles, emails, and any content that reads like normal sentences (as opposed to titles or headings which use title case).
How does the tool know where sentences begin?
The tool identifies sentence boundaries by looking for sentence-ending punctuation (periods, question marks, exclamation points) followed by a space and then a letter. It capitalizes the first letter after these punctuation marks. It handles standard sentence structures but may not catch unusual punctuation patterns.
Will this preserve proper nouns like names?
By default, the tool lowercases everything except the first letter of sentences. If you enable "Preserve Proper Nouns" option, it will attempt to keep already-capitalized words as-is, assuming they might be names or proper nouns. However, if your input is all caps or all lowercase, the tool cannot identify which words should be proper nouns.
What about the word "I" - will it be capitalized?
Standard sentence case doesn't automatically capitalize the pronoun "I" when it appears mid-sentence (though grammatically it should be). If you need "I" capitalized, you'll need to manually fix these instances after conversion, or use the "Preserve Proper Nouns" option if your input already has "I" capitalized.
Does it work with abbreviations like "Dr." or "Mr."?
Abbreviations ending with periods can confuse sentence detection. "Dr. Smith" might cause the tool to think a new sentence starts at "Smith". For best results with heavily abbreviated text, you may need to manually review the output. Most common text works fine, but technical or heavily abbreviated content may need adjustments.
What's the difference between sentence case and lowercase?
Lowercase converts everything to small letters with no capitals at all ("hello. how are you?"). Sentence case capitalizes the first letter of each sentence ("Hello. How are you?"). Sentence case is grammatically correct for standard writing; pure lowercase is not.
Can I use this for code or programming?
This tool is designed for natural language text, not code. Programming languages have their own capitalization conventions (camelCase, PascalCase, snake_case) that this tool doesn't follow. Use language-specific code formatters for programming. This tool is for prose, documentation, comments, or string content.
Will it remove extra spaces or fix punctuation?
No, the tool only changes capitalization. It preserves all spaces, punctuation, line breaks, and other formatting exactly as-is. If you need to clean up spacing or punctuation, use those separately, then apply sentence case conversion.
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