Capitalize Sentences
Automatically capitalize the first letter of every sentence in your text. Fix uncapitalized text and ensure proper sentence-level capitalization instantly.
Fixing Text That Lost Its Capitalization
Text loses its capitalization in many common situations. Copy-pasting from PDFs, voice transcription software, OCR tools, and messaging apps often strips or mangles sentence-starting capitals. All-caps text copied from legal documents, product labels, or spreadsheets needs to be converted back to readable form. Notes taken quickly, transcripts exported from meeting software, and text scraped from websites all frequently arrive without proper sentence case. This tool corrects all of these cases in a single click.
Sentence Case Rules
Sentence case means the first letter of each sentence is capitalized and all remaining letters are lowercase, except for proper nouns and the pronoun "I." Sentence boundaries are marked by periods, exclamation marks, and question marks followed by a space, as well as line breaks that start a new paragraph. This is the standard capitalization style for most body text in English, used in articles, emails, messages, and general writing. It differs from title case, which capitalizes the first letter of most words, and from ALL CAPS, which capitalizes every letter. For a tool that handles title-style capitalization, see our title case converter.
When to Use Sentence Capitalization
Sentence capitalization is appropriate for body text in articles, blog posts, emails, social media captions, and most everyday writing. It is also the correct style for dialogue in fiction and for captions beneath images. When pasting text into a CMS, email editor, or word processor, incorrect capitalization is immediately noticeable and affects the perceived quality of the content. Running your text through this tool before publishing or sending ensures that every sentence starts correctly. To understand the full set of rules behind which words should be capitalized, visit our capitalization rules in English reference. After fixing capitalization, you can also check grammar using our grammar checker to catch any remaining errors.
Sentence-Case Conversion in One Click
The instant capitalizer on this page processes your text entirely in the browser with no server calls and no delay. You paste your text, select the capitalization mode that matches your situation, and click the button. The corrected text appears immediately with a copy button so you can use it right away. For more complex cases where the sentence structure is ambiguous or where the text needs intelligent rewriting alongside capitalization fixes, the AI tab in the left panel handles those situations.
How to Capitalize Sentences in Three Steps
Paste Your Text
Copy text from any source — a PDF, transcript, note, email, spreadsheet, or website — and paste it into the textarea on this page or in the left panel.
Choose a Mode
Select "Capitalize first letter of each sentence" for standard correction, "Convert ALL CAPS to sentence case" for uppercase text, or "Capitalize after .!? only" for targeted punctuation-based capitalization.
Click and Copy
Click "Capitalize Sentences" to see the corrected text instantly. Use the copy button to grab the result and paste it wherever you need it.
Options Available
The tool offers three capitalization modes. Capitalize first letter of each sentence finds every sentence boundary and capitalizes the first character after it, leaving the rest of the text unchanged. This is the safest mode for mixed-case text that mostly has correct casing but is missing sentence starters. Convert ALL CAPS to sentence case first lowercases the entire text and then applies sentence capitalization, which is ideal for text that was originally written or exported in all uppercase. Capitalize after .!? only limits capitalization to characters that follow a period, exclamation mark, or question mark, which is useful when your text has a specific structure that should not be changed in other ways. Two optional extras let you automatically capitalize the standalone pronoun "I" and capitalize a set of common proper nouns including days of the week, months, nationalities, and major brand names.
Repairing OCR Output, Voice Transcripts, and Notes
Three of the most common sources of capitalization errors are optical character recognition output, voice-to-text transcription, and quick personal notes. Each source produces a specific pattern of missing or broken capitalization that this tool corrects directly.
Fixing Uncapitalized Text
OCR software converts scanned images of text into digital characters. When the scan quality is low or the font is unusual, the OCR engine sometimes fails to recognize capital letters and outputs entire paragraphs in lowercase. The result is readable but looks unprofessional and incorrect. Pasting OCR output through this capitalizer fixes every sentence start without altering the words themselves. If the OCR output also has extra line breaks or formatting issues, use our remove line breaks tool to clean those up before or after capitalizing.
Converting All-Caps to Proper Case
Voice transcription tools such as dictation software and meeting recorders often output text in all lowercase or all uppercase depending on the platform and settings. When text arrives in all caps, selecting the "Convert ALL CAPS to sentence case" mode lowercases the entire block first and then applies sentence capitalization, producing a clean, readable result. This mode is also effective for converting legal documents, product specifications, and spreadsheet data that was entered in all caps for emphasis or as a convention. After converting, you can check the output with our AI writing checker to catch any additional issues.
Cleaning Transcriptions
Meeting transcripts, podcast scripts, and interview notes exported from transcription services frequently lack sentence-starting capitals. The transcription engine captures words accurately but does not always apply punctuation and capitalization correctly, especially when speakers talk quickly or overlap. Running the transcript through this capitalizer restores sentence starters based on the punctuation already present in the text. For transcripts that also need paragraph structure added, our auto break text into paragraphs tool can split a long block of text into readable paragraphs automatically.
ALL CAPS to Sentence Case - Fixing Shouted Text
Text written entirely in uppercase is difficult to read and carries an unintended tone of urgency or aggression in digital communication. Converting all-caps text to sentence case makes it immediately more readable and appropriate for use in content, emails, and documents. The all-caps to sentence case mode handles this conversion in a single step.
Capitalizing Lowercase Text
Text that arrives in all lowercase — from a quick message, an exported data field, or a script that stripped capitalization — needs the first character of each sentence restored. The "Capitalize first letter of each sentence" mode handles this precisely. It scans the text for periods, exclamation marks, question marks, and line breaks, then capitalizes the first letter that follows each boundary. Words in the middle of sentences are left untouched, which preserves any intentional lowercase styling or proper noun casing already in the text. You can also combine this with the "Capitalize 'I' pronoun" option to fix the most common capitalization omission in casual writing.
Fixing ALL CAPS
Converting all-caps text requires a two-step process: first lowercase everything, then apply sentence capitalization. This tool does both in one action when you select the "Convert ALL CAPS to sentence case" mode. The conversion is particularly useful for product labels, legal disclaimers, form field data entered in caps lock, and any text that was formatted in uppercase for visual or technical reasons. After conversion, the optional proper noun capitalizer will attempt to restore correct casing for common names, days, months, and brands that were lowercased in the first step. For replacing specific words or phrases in the converted text, use our replace text online tool.
Multi-Paragraph Capitalization
The capitalizer handles multi-paragraph text correctly. Each paragraph is treated as starting a new sentence, so the first letter of each paragraph is capitalized regardless of whether the previous paragraph ended with punctuation. Within each paragraph, sentence boundaries are detected through periods, exclamation marks, and question marks followed by whitespace. Long documents with many paragraphs are processed in a single pass, making this tool practical for cleaning entire articles, reports, and transcripts rather than just single sentences. For additional text cleaning options such as removing extra spaces or whitespace, see our remove white spaces tool.
FAQ
What is sentence case?
Sentence case is a capitalization style where only the first letter of the first word in a sentence is capitalized, along with proper nouns and the pronoun 'I'. All other words in the sentence are written in lowercase. It is the standard capitalization style for most body text in English, used in articles, emails, social media posts, and general writing. It contrasts with title case, which capitalizes the first letter of most words, and with ALL CAPS, which capitalizes every letter.
Does it handle abbreviations?
The instant capitalizer uses punctuation marks as sentence boundary indicators. If your text contains abbreviations that end with a period — such as 'Dr.', 'Mr.', 'etc.', or 'vs.' — the tool may incorrectly treat the period as a sentence end and capitalize the next word. This is a known limitation of punctuation-based capitalization logic. For text containing many abbreviations, the AI tab in the left panel handles these cases more intelligently, since the AI understands context and can distinguish abbreviations from sentence endings.
Will it fix ALL CAPS text?
Yes. Select the 'Convert ALL CAPS to sentence case' mode and the tool will first lowercase all characters in your text, then apply sentence capitalization to the result. This effectively converts shouted or all-uppercase text into properly cased, readable sentences. The optional proper noun capitalizer can then restore capitalization for common names, days, months, and brands that were lowercased in the first step.
Does it capitalize 'I'?
Yes, the 'Capitalize I pronoun' option is enabled by default. When active, it replaces every standalone lowercase 'i' (the first-person singular pronoun) with an uppercase 'I'. This option is applied after the main capitalization mode, so it works correctly regardless of which mode you choose. It only affects the pronoun 'i' when it appears as a standalone word, not the letter 'i' inside words.
Can it detect proper nouns?
The tool includes a basic proper noun capitalizer that covers common categories: days of the week, months of the year, nationalities, and a selection of well-known brand names. Enable the 'Capitalize common proper nouns' option to apply this. The list covers the most frequent cases but does not include all possible proper nouns such as people's names, place names, or less common brands. For comprehensive proper noun detection, use the AI tab and ask the AI to fix proper noun capitalization in your text.
What is title capitalization tool?
A title capitalization tool capitalizes the first letter of most words in a title or heading, following specific rules about which words to capitalize and which to leave lowercase (such as prepositions, articles, and conjunctions shorter than a certain length). This is different from sentence case, which only capitalizes the first word. Title capitalization is used for book titles, article headings, movie names, and formal document titles.
What is all caps generator?
An all caps generator converts normal mixed-case or lowercase text into ALL UPPERCASE letters. It is the opposite of the sentence case converter on this page. All caps text is commonly used for emphasis, acronyms, headings in certain design contexts, and data entry in fields that require uppercase. To convert all caps back to sentence case, use the 'Convert ALL CAPS to sentence case' mode on this tool.
What is auto capitalisation?
Auto capitalisation (or auto capitalization in American English) is a feature in text editors, keyboards, and writing tools that automatically applies capital letters at the start of sentences as you type. This tool is a standalone auto capitalisation utility that applies the same logic to existing text you paste in, making it useful for fixing text that was typed without auto caps enabled or that came from a source where auto capitalization was not available.
What is auto capitalization?
Auto capitalization is the automatic application of capital letters to the first word of each sentence. On mobile devices and in word processors, auto capitalization happens in real time as you type. This capitalize sentences tool applies the same logic to text after the fact, allowing you to fix any block of text regardless of where it came from. It works on text from emails, transcripts, notes, spreadsheets, PDFs, and any other source.