lowercase Converter — When to Write Everything in Small Caps

Where lowercase is technically required

In several technical contexts, lowercase is not a stylistic preference but a hard requirement or a de facto standard that avoids bugs.

• URL paths: web server paths on Linux are case-sensitive. /Image-Compressor and /image-compressor are different resources. Use all-lowercase paths consistently to avoid duplicate content penalties and 404 errors from case mismatches.
• HTML tag names and attribute names: the HTML5 specification defines element and attribute names in lowercase. While browsers are forgiving, validators and XML-mode parsers reject uppercase tags. Write <input type="text">, not <INPUT TYPE="TEXT">.
• CSS property names and selectors: CSS property names are case-insensitive in most browsers, but class selectors are case-sensitive. .NavBar and .navbar are different classes. Stick to lowercase class names.
• npm package names: the npm registry rejects package names with uppercase letters. All package names must be lowercase (e.g. react-dom, not React-Dom).
• Docker image names and tags: Docker image names must be lowercase. Attempting to build or pull MyApp:Latest will result in an error on Docker Hub and most registries.
• Unix/Linux file names: while not strictly required, lowercase file names avoid ambiguity and mismatches when scripts process directories. README.md is a conventional exception.

lowercase as brand voice

Several technology brands intentionally use all-lowercase as part of their identity: github (in early branding), tumblr, flickr, unsplash. This conveys approachability, minimalism and a tech-native aesthetic.

If your brand or product uses lowercase as a deliberate stylistic choice, document it explicitly in your brand guidelines. Lowercase brand names still follow normal capitalisation rules at the start of sentences in editorial contexts, unless the brand owner has formally waived this (as iPhone and eBay have for their own names).

lowercase in database design

SQL is case-insensitive for keywords (SELECT and select are equivalent), but column and table names are case-sensitive in PostgreSQL when quoted. The standard practice is to write all table names, column names and schema names in lowercase snake_case without quotes: user_profiles, created_at, order_id.

This avoids the painful situation where a column named UserID in a CREATE TABLE statement becomes accessible only as "UserID" (with quotes) in subsequent queries, while user_id can be written without quotes in any casing.

Frequently asked questions