Lowercase Converter
Convert text to lowercase instantly, for free.
This tool runs entirely in your browser. Your files are never uploaded to a server.
What this tool does
Converts any text to lowercase, using JavaScript's standard Unicode case mapping — every letter it recognizes as having a lowercase form is converted, non-letters are left unchanged.
How to use it
Type or paste text into the box; the lowercase result appears below and updates as you type. Buttons above the box switch to six other case styles — UPPERCASE, Title Case, Capitalized Case, Sentence case, aLtErNaTiNg cAsE, and iNVERSE cASE — without leaving the page.
Worked example
"HELLO WORLD" becomes "hello world", and accented letters are handled too: "CAFÉ" becomes "café", keeping the acute accent on the é.
Method
The conversion calls JavaScript's built-in String.prototype.toLowerCase(), which applies the Unicode default case-mapping algorithm — the same one used throughout modern browsers — rather than a locale-specific one.
A Turkish edge case to know
The Turkish capital İ (dotted I, U+0130) doesn't lowercase to a plain "i" under this default mapping — it becomes "i" plus a separate combining dot-above character, so "İSTANBUL" becomes "i̇stanbul", which looks almost identical on screen but is actually nine characters long instead of eight. That extra invisible character can break exact-text comparisons or search, and Turkish orthography itself expects plain "istanbul" here — a Turkish-locale-aware tool is needed to get that right.
Limitations
This lowercases the whole text uniformly; it doesn't offer sentence-aware or title capitalization in reverse — use the other mode buttons if you need a different style. It also can't restore an original mixed-case string once it's been lowercased, since case information is discarded in the conversion.
Privacy and processing
The conversion runs entirely in your browser using JavaScript. Nothing you type is uploaded or stored.
Frequently Asked Questions
- Does this handle accented letters and other languages?
- Yes — it uses JavaScript's Unicode-aware toLowerCase(), so accented Latin letters (CAFÉ → café), Cyrillic, Greek and many other scripts convert correctly.
- Why does İSTANBUL become i̇stanbul with an odd extra mark?
- The Turkish capital İ (dotted I) has no plain lowercase equivalent in JavaScript's default mapping, so it becomes "i" plus a separate combining dot character — nine characters instead of the eight in "istanbul". This is a known limitation, sometimes called the "Turkish I problem."
- Can I turn the lowercase text back into the original?
- No — lowercasing discards information about which letters were originally capitalized. Keep a copy of your original text if you need it later.
- What other case styles can I switch to?
- UPPERCASE, Title Case, Capitalized Case, Sentence case, aLtErNaTiNg cAsE, and iNVERSE cASE are all available from the buttons above the text box, using the same input.