Convert Filenames to Lowercase

Convert all uppercase letters in filenames to lowercase with optional extension inclusion.

How It Works & Processing Standards

Convert all uppercase letters in filenames to lowercase with optional extension inclusion.

Your input data is never sent to any server and is securely processed on your device.

Current Limits

  • Desktop max file size: 100MB
  • Mobile max file size: 40MB

Convert Filenames to Lowercase is a 100% free, browser-based online utility. All calculations and file conversions run locally inside your browser (Local-First) without sending data to remote servers, keeping your documents and inputs strictly private.

How to Use Convert Filenames to Lowercase

  1. 1
    Select FilesPick files with uppercase letters.
  2. 2
    Toggle Extension OptionChoose whether to also lowercase file extensions.
  3. 3
    Download Renamed FilesSave all lowercase files in a ZIP.

Common Use Cases

  • Normalizing image asset names for Linux production web servers
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