lowercase Converter
Convert any text to lowercase instantly. All letters become small letters.
What is lowercase?
Lowercase means every letter is in its small form. It is the default reading format for body text in virtually every written language and is required in many technical contexts such as email addresses, URLs, and command-line inputs.
HELLO WORLD→hello worldWhen to Use lowercase
Use lowercase for body text, email addresses, URLs, file names on case-sensitive systems (Linux), and CSS class names for consistency across your codebase.
Avoid all-lowercase for headings, proper nouns, names, or the first word of a sentence — it signals either poor grammar or a deliberate stylistic choice (like e.e. cummings poetry).
Industry Standard
RFC 5321 (SMTP standard) specifies that email local parts are case-sensitive, but domain names per RFC 1035 are case-insensitive and universally written in lowercase.
How to Use This lowercase Converter
- Paste or type your text into the Input Text box on the left.
- The output is converted to lowercase instantly on the right.
- Click Copy to copy the result to your clipboard.
- Use Clear to reset and convert new text.
lowercase in Programming Languages
str.toLowerCase()str.lower()strtolower($str)str.toLowerCase()str.downcaseFrequently Asked Questions
Is this lowercase converter free?
Yes, completely free — no signup, no account, no limits.
Does my text get stored or sent anywhere?
No. All conversions happen entirely in your browser using JavaScript. Your text never leaves your device and is never sent to any server.
When should I use lowercase?
Use lowercase for body text, email addresses, URLs, file names on case-sensitive systems (Linux), and CSS class names for consistency across your codebase.
Expert tip
On Linux and macOS, file names are case-sensitive. "README.md" and "readme.md" are different files. Always use lowercase for project file names to avoid cross-platform issues.