File Name Cleaner: Strip Symbols and Fix Casing

Have you ever saved a file named Screen Shot 2026-08-10 at 10.45.12 AM.png? The File Name Cleaner turns messy names like that into consistent names. It cleans a whole list of names in one pass.

The tool suits students, photographers, office staff, and anyone who sorts many files. You paste one name per line into the text box. Pick a naming convention, and the cleaned list appears as you type.

Table of Contents

• What the File Name Cleaner Does
• How to Use the File Name Cleaner
• The Cleaning Steps and Formula
• Worked Example
• How to Read the Results
• Naming Tips and Case Styles
• Limitations and Assumptions
• FAQs About the File Name Cleaner

What the File Name Cleaner Does

Each non-blank line produces one cleaned name, in the same order as your input.

• Symbol removal: keeps letters and digits from any alphabet, spaces, hyphens, underscores, and dots inside words.
• Four naming conventions: kebab-case, snake_case, camelCase, and lowercase.
• Space Replacement: sets the separator for lowercase names only.

How to Use the File Name Cleaner

The output updates as you type, so the tool has no Clean button.

1. Paste or type your file names into Messy File Names (One Per Line).
2. Open Naming Convention and choose kebab-case, snake_case, camelCase, or lowercase.
3. If you chose lowercase, open Space Replacement and choose hyphen, underscore, dot, or remove spaces.
4. Read the names in Sanitized File Names, and check the message box for warnings.
5. Press Copy Clean Names to copy the whole list.
6. Rename your real files by hand, matching each cleaned line to its original.

Space Replacement is disabled for the other three conventions, because those styles set their own separators.

The Cleaning Steps and Formula

The tool treats each non-blank line as one file name. It splits off the extension first, then cleans the name and joins its words again.

• Name is the text before the last dot. Extension is that last dot and the text after it. A leading dot in a hidden file, such as .gitignore, stays.
• If the text after the last dot contains a space, the whole line counts as the name. Report v1.2 final keeps its dot.
• Extension cleaning lowercases the extension and keeps only letters and digits. Notes.txt? becomes .txt.
• Remove Symbols keeps letters, digits, spaces, hyphens, underscores, and dots. Accent marks are removed, so Résumé becomes Resume.
• Split Into Words splits on spaces, hyphens, and underscores. Dots stay inside a word, but dots at a word edge are dropped, so Dr. becomes dr.
• Apply Style joins the words. kebab-case uses hyphens, and snake_case uses underscores. camelCase lowercases each word, then capitalizes every word after the first. Lowercase uses your Space Replacement choice.
• Empty names have no letters or digits left. They become cleaned-file, cleaned_file, or cleanedFile, to match the style.

Worked Example

Priya saved four files from her phone and her laptop. She keeps the default settings, which use kebab-case with hyphens. She pastes all four lines into the Messy File Names box.

The result cards read 4 Files, kebab-case, and Cleaned, because no warning applies. Tomas uses other settings. His photo named Holiday Photos 2026.JPG becomes holiday_photos_2026.jpg in snake_case. His file invoice final copy.pdf becomes invoiceFinalCopy.pdf in camelCase.

Lena pastes My File.png, my-file.png, and MY_FILE.PNG in kebab-case. The output shows my-file.png, my-file-2.png, and my-file-3.png, and the Status shows Warning.

How to Read the Results

• Input Files counts the non-blank lines in the input box. One line shows 1 File, and an empty box shows 0 Files.
• Case Style shows the convention name: kebab-case, snake_case, camelCase, or lowercase.
• Status shows Empty for no input, Warning when the message box has a warning, and Cleaned otherwise.
• Sanitized File Names holds one cleaned name per line, in your input order.
• Message box appears when the input is blank or a line needs attention. Read it before you rename.

Naming Tips and Case Styles

Kebab-case, with hyphens, is easy to read in web addresses and many content systems. Snake_case is a common choice for code and data files.

Avoid the dot separator for most work. The tool shows a warning when you use it. A name such as my.file.name.png looks like it has several extensions. Some software reads only the last dot as the extension.

Keep one style for a whole batch, so files sort in a predictable order.

Check the File Extension Finder when you are unsure which extension a file uses. For fresh names from scratch, try the File Name Generator.

The File Name Sanitizer offers another way to format names, so it suits a second check. Browse the Developer Tools hub.

Limitations and Assumptions

• The tool handles pasted text only. It cannot open, rename, or move files on your computer.
• The symbol list is fixed, so legal characters are removed too. Tom's Notes.txt becomes toms-notes.txt, and Budget @ 2026+1.txt becomes budget-20261.txt.
• Letters from other scripts stay as written, because the tool does not romanize them. A name such as 报告.docx stays unchanged.
• Lines with a slash or backslash are left out, not split into folder and file names. For example, C:\Users\dell\file.txt produces no output line.
• Names longer than 255 characters get a warning, but the tool does not shorten them. For long names, the File Name Shortener can help.
• Reserved Windows names such as CON.txt become con.txt, with a warning. The tool flags the name but does not make it safe for Windows.
• The tool cannot see your folders, so it cannot detect names that already exist. Run the duplicate file name checker before you rename.

FAQs About the File Name Cleaner

This calculator gives general estimates only and is not professional advice. Reviewed for general accuracy by Prof. Dr. Khalil Mudassar, PhD.