Capitalize Sentences – Free Online Tool
Free online Capitalize Sentences tool to capitalize the first letter of each sentence automatically. Fix capitalization errors and format text properly. Perfect for editing and proofreading content.
Example Output
First letter after each . ! ? capitalized.
Hello. How are you? I am fine.
What is Capitalize Sentences?
Capitalize Sentences rewrites text so the first letter of every sentence is uppercase. Useful when you receive all-lowercase content (chat exports, voice-to-text transcripts) and need a properly-capitalised version for emails or documents.
Why use this tool?
- Touch-friendly UI, fine on phones for on-the-go edits
- No registration, account, or installation required
- No API keys to manage and no rate limits to monitor
- Handles Unicode correctly — emoji, CJK, Arabic, and accented Latin all stay intact
- Cleanly handles pasted content with mixed line endings (CRLF, LF, CR)
How to use
- Paste your text with mixed-case or all-lowercase content
- Click Process — the first letter of each sentence is capitalized
- Sentence boundaries detected via . ! ? followed by space
- Copy the result for use in formal writing
Examples
Chat transcript cleanup
Casual lowercase chat → properly capitalized sentences. Saves manual editing for everything except names.
Voice-to-text fix
Some speech-to-text engines skip capitalization. Pipe their output through this tool first.
Common use cases
- Cleaning casual all-lowercase writing
- Post-processing speech-to-text output
- Reformatting chat logs for documentation
- Standardising tone for formal emails
Troubleshooting
- Proper nouns (names, places) not capitalised.
- The tool only knows about sentence boundaries, not proper nouns. Capitalize "John", "Vietnam", etc. manually after running.
Frequently Asked Questions
The tool identifies sentence boundaries (periods, exclamation marks, question marks) and capitalizes the first letter after each sentence ending punctuation.
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