Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Convert text to UPPERCASE or lowercase.
Your result will appear here.
A focused UPPERCASE/lowercase toggle for when you just need one of those two conversions quickly. For every other case style -- Title Case, Sentence case, camelCase, snake_case, and more -- see the full Case Converter tool, which handles all of them at once.
Paste your text, choose UPPERCASE or lowercase, and the converted result appears instantly.
The tool has exactly two modes. UPPERCASE turns every lowercase letter in your text into its capital form, and lowercase turns every capital into its small form. Anything that is not a letter, such as digits, punctuation, emoji, spaces, and line breaks, is left exactly as you typed it. The line structure of your text is preserved, so a multi-paragraph pasted document keeps its paragraphs. The conversion uses the standard rules built into your browser, which also handle accented letters in many languages.
Take the hypothetical text: "Meeting Notes: Q3 Budget Review at 2pm". In UPPERCASE mode it becomes "MEETING NOTES: Q3 BUDGET REVIEW AT 2PM". In lowercase mode it becomes "meeting notes: q3 budget review at 2pm". Notice the digit 3 and the colon are unchanged, and that the mode acts on the whole text at once rather than word by word. Switching modes reconverts from your original input, not from the previous output, so you can toggle freely without compounding changes.
Blanket conversion cannot know which words should keep capitals. Converting a document to lowercase removes the capital letters from names, places, the pronoun I, and acronyms, and you will have to restore them by hand. Likewise, UPPERCASE can change how some characters behave in specific languages. A common example is the German sharp s, which becomes two letters when uppercased. Turkish also has special dotted and dotless i rules that a general conversion may not follow the way a Turkish speaker expects. If your text is in a language with such rules, review the output carefully.
Also consider readability. Long passages in all capitals are harder and slower to read than normal sentence case, and some readers take capitals in an email or message as shouting. Use full uppercase for short labels and emphasis, not for body text.
A typical routine looks like this. Paste your text, choose a mode, then copy the result from the output box. You can also download it as a plain text file if you prefer to save it. Because everything happens in the browser, you can convert sensitive drafts without uploading them anywhere. If you need something more specific than a plain uppercase or lowercase pass, such as capitalizing every word or converting to a programming naming style, use the full Case Converter tool mentioned above instead of stacking manual edits.
If you are working with a big block of text, it is worth scanning the result once for details that a mechanical conversion cannot fix: abbreviations, product names with intentional mixed case, and units such as kB or MHz where capitalization changes the meaning.
No -- the conversion happens entirely in your browser.
See the Case Converter tool, which covers Title Case, Sentence case, camelCase, PascalCase, snake_case, and kebab-case all at once.
No. Only letters are affected. Digits, punctuation, spaces, and line breaks stay exactly as they are.
Not from the converted output, because the original capital positions are lost. Keep your original text in the input box, since switching modes always converts from that input.
No. This tool converts the whole text to all capitals or all small letters. For sentence starts, use the First Letter Capitalizer; for Title Case, use the Case Converter.
Generally yes, since the browser applies its standard case rules, but language-specific exceptions exist, so check results in languages like Turkish or German.