Sentence Case Converter - Capitalize Sentences

A sentence case converter capitalizes the first letter of each sentence while keeping the rest of the words in lowercase (unless they’re proper nouns or acronyms). It helps clean drafts, emails, and pasted text that arrived in all caps or odd casing. Processing stays in your browser for privacy.

1. Paste text: Add paragraphs, emails, or notes.
2. Convert: Click Sentence case to apply capitalization.
3. Copy or download: Copy the result or save it as a text file.

• Readable drafts: Fix shouty or inconsistent text quickly.
• Fast cleanup: Save time on manual capitalization edits.
• Local privacy: No content is uploaded or stored.

Use case 1: Email replies

Convert ALL-CAPS messages to sentence case before responding.

Use case 2: Content imports

Clean scraped or migrated text that lost its casing.

Use case 3: Documentation

Standardize release notes or changelogs to sentence case for clarity.

Basic example

Input: WELCOME TO THE LAUNCH. PLEASE JOIN THE CALL.
Output: Welcome to the launch. Please join the call.

Advanced example

Input: Mixed-case multi-sentence paragraph with acronyms
Output: First letters capitalized; acronyms like API stay uppercase.

Acronym handling

If your acronyms get lowercased, re-toggle them manually; the tool can’t infer every exception.

Missing punctuation

Without periods, the tool can’t detect sentence boundaries. Add punctuation first.

• Use the title case converter for headlines and the lowercase converter for uniform casing.
• Run the word frequency counter after conversion to check repetition.
• Remove formatting first with the plain text converter for cleaner results.

• Switch among cases in one place with the case converter.
• Fix shouty inputs using the lowercase converter before applying sentence case.

All conversion happens locally in your browser. No text is uploaded or stored.