Uppercase / Lowercase
Convert text to uppercase, lowercase, capitalized and other formats.
About this tool
The Uppercase / Lowercase tool converts any text between six different capitalization styles instantly and without any size limit. Paste your text in the top area and choose the desired mode: UPPERCASE, lowercase, Capitalize Each Word, Sentence case, aLtErNaTiNg, or iNvErSe.
The workflow is straightforward: paste the text, click the style button you want, and the result appears below with a copy button. You can switch modes as many times as you like without losing the original — it stays preserved in the input area.
Practical scenarios are plentiful. Developers need SCREAMING_SNAKE_CASE or Title Case for constants and headings. Content creators want to standardize captions or titles without retyping. Anyone who receives text in ALL CAPS can quickly convert it to lowercase before editing. The "Sentence case" mode is especially useful for text pasted without correct punctuation. The inverted mode is popular for creating visual effects on social media.
All processing happens in your browser using JavaScript's native APIs. No character you type is transmitted to external servers — the tool works even offline once the page has loaded. No account or personal data is required.
Frequently asked questions
Is the tool free?
Yes, completely free, with no character limit and no sign-up required.
Is my text sent to any server?
No. The conversion happens entirely in your browser. The text never leaves your device.
Does it work on mobile?
Yes. The layout adapts to smaller screens and all mode buttons work normally on mobile devices.
What is the difference between 'Capitalize' and 'Sentence case'?
'Capitalize' uppercases the first letter of every word. 'Sentence case' keeps all other words lowercase and only capitalizes after '.', '!', or '?'.
What does the 'Inverse' mode do exactly?
It swaps the capitalization of each individual character: uppercase letters become lowercase and vice versa. The result is text with an alternating appearance, commonly used in memes and ironic posts.