Change Case: Convert Filenames to Any Case Style
Batchio's Change Case rule converts filenames to UPPERCASE, lowercase, Title Case, Sentence case, or camelCase in a single click. Pick the style you need, and the live preview shows the result for every file before you apply.
What case options does Batchio support?
Each case option applies to the base filename while leaving the extension unchanged. Selecting UPPERCASE converts vacation photo.jpg to VACATION PHOTO.jpg, and lowercase turns REPORT_FINAL.pdf into report_final.pdf. The extension is always preserved in its original form, because changing it could cause macOS to misidentify the file type.
The case conversion is Unicode aware, so accented characters like é, ü, and ñ are handled correctly. This matters when working with filenames in languages that use diacritical marks. Batchio uses the native macOS text system for case transformation, which means the results match what you would get from any other Apple app.
How do you convert filenames to lowercase on Mac?
Lowercase filenames are the standard for web assets, code repositories, and many server environments where the file system is case sensitive. A folder full of inconsistently cased files can cause broken links, missing images, and deployment errors. With Batchio, you select the files, pick lowercase, and the entire batch is normalized in one step. The live preview lets you verify that every name looks correct before you commit.
If some files contain special characters or spaces that also need cleaning, you can chain the Change Case rule with a Remove Characters rule. For example, first convert to lowercase and then replace spaces with underscores. Both transformations execute in a single pass, and the preview reflects the cumulative result of all active rules.
When should you use Title Case vs Sentence case?
Title Case is the better choice when filenames represent proper titles, such as presentation slides, marketing assets, or portfolio pieces. Converting quarterly sales report.pptx to Quarterly Sales Report.pptx immediately makes the filename more presentable in shared folders and file browsers. Batchio treats common separators like underscores, hyphens, and spaces as word boundaries when applying Title Case.
Sentence case is more appropriate when you want a clean, readable filename without the visual weight of every word being capitalized. It produces results like Meeting notes march.docx, which feels natural in personal folders and note archives. If you need to refine the output further, a Find & Replace rule can capitalize specific words or abbreviations that Sentence case leaves lowercase.
What is camelCase and when is it useful for filenames?
myProjectFile.js. It is widely used in programming and web development for consistent, space free naming.Developers frequently need filenames that follow camelCase conventions to match the naming patterns of their codebase. When component files, test files, or configuration files use camelCase, the entire project feels more coherent. Batchio converts any filename to camelCase by stripping spaces and capitalizing word boundaries. A file named user profile settings.json becomes userProfileSettings.json.
camelCase is also useful outside of programming when you need space free filenames that remain readable. Uploading files to systems that do not handle spaces well, such as certain FTP servers or legacy tools, becomes simpler when the names are already camelCased. Our guide to changing filename case covers each case style with practical examples for developers and content creators.
Normalize Your Filenames in One Click
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Marcel Iseli is an indie app developer and the creator of Batchio. He builds native macOS utilities focused on productivity and file management, with a focus on lightweight, subscription-free tools.