Letter Capitalizer for X / Twitter

Click the toolbar button on any X / Twitter page (post, thread, or article) to fix lowercase capitalization in the post on screen.

Tired of X and Twitter posts written entirely in lowercase? Letter Capitalizer fixes that with one click. Open any X or Twitter page, whether it is a single post, a thread, or a full article, then click the toolbar button. The extension rewrites the post text on screen so that sentences start with capital letters again. What it does: ✅ Capitalizes the first letter of each sentence after a period, question mark, or exclamation point ✅ Capitalizes the first letter of each new line, list item, paragraph, and heading, so even a bold header with no period still capitalizes the line that follows it ✅ Standalone `i` and contractions (`i'm`, `i'll`, `i've`, `i'd`) become `I` ✅ Leaves @mentions, #hashtags, $cashtags, links, and existing CAPS untouched Everything happens locally in your browser. The extension makes no network requests, collects no data, and only runs on the page when you click the button. It works on x.com and twitter.com. Please note this is a rules based tool. It does not capitalize proper nouns in the middle of a sentence, because it cannot know that a word is somebody's name or a place.