Uppercase to Lowercase Converter
Paste or type any text and instantly see it converted to all lowercase — with a full count of how many uppercase letters were changed, plus digits, spaces, and symbols.
How does this calculator work?
Every uppercase letter in the input is replaced with its lowercase equivalent; digits, spaces, and symbols are unchanged. The result is the Unicode lowercase of the original text. Use this to normalise search terms, clean data exports, or prepare case-insensitive comparisons.
Formula
How this is calculated
Uppercase-to-lowercase conversion applies Unicode case folding: every letter that has a defined lowercase equivalent is replaced with that equivalent, and all other characters (digits, punctuation, spaces, emoji) are passed through unchanged. In modern Unicode, this covers the full range of Latin, Greek, Cyrillic, Arabic, and other scripts — not just the basic A–Z range.
The converter counts each character type so you can see at a glance how much of the text was actively changed (uppercase letters), how much was already lowercase, and how many characters were untouched (digits, spaces, symbols). This is useful when processing data exports, normalising user input for search indexes, or preparing text for case-sensitive systems.
Note that converting to lowercase is lossy — the original capitalisation cannot be recovered from the output alone. If you need to preserve the original, keep a copy. For title case or sentence case, reverse the process selectively rather than using a blanket lowercase pass.
Frequently asked questions
Yes. The converter uses JavaScript's built-in .toLowerCase() method, which applies Unicode case folding and correctly handles accented Latin letters, Greek capitals, Cyrillic, and most other scripts. A few edge cases (e.g., the Turkish dotted İ/dotless ı) may need locale-aware lowercase (toLocaleLowerCase("tr")); for typical European and technical text it works as expected.
No. Digits (0–9), spaces, newlines, punctuation, and symbols have no lowercase equivalents and are passed through unchanged. Only letters with a defined lowercase form are converted.
The converter runs entirely in your browser — there is no server-side limit. Very long texts (millions of characters) may run slowly on lower-powered devices, but for typical document lengths it is instant.
Also known as
TG we-Calculate Editorial Team. (2026). Uppercase to Lowercase Converter [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/uppercase-to-lowercase-converter
TG we-Calculate Editorial Team. "Uppercase to Lowercase Converter." TG we-Calculate. 2026. https://we-calculate.com/calculator/uppercase-to-lowercase-converter.
TG we-Calculate Editorial Team, "Uppercase to Lowercase Converter," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/uppercase-to-lowercase-converter
@misc{wecalculate_uppercase_to_lowercase_converter, title = {Uppercase to Lowercase Converter}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/uppercase-to-lowercase-converter}}, year = {2026}, note = {TG we-Calculate} }
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