Bulk File Renamer

How to use

1. 1Paste filenames one per line in the input, or click Pick files to populate the list from a folder on your device (only the names are read).
2. 2Try a quick preset like Spaces to hyphens, Sequential numbering, or snake_case to start from a sensible default.
3. 3Tune the controls on the right: find and replace inside the stem, change whitespace and letter case, add a prefix and suffix, insert sequential numbers with start, step, and pad width, or change the extension.
4. 4Watch the live preview. Original is on the left, new name on the right. Amber rows flag duplicates that would collide in the output set.
5. 5Copy the new names, the report, or a Bash, PowerShell, or Windows cmd rename script. Run it inside the folder that holds the original files. Always back up first.

About this tool

Bulk File Renamer turns a list of filenames into a clean, predictable new list in one pass. Paste names one per line or pick files from your device (only the names are read, never the contents), then apply a stack of transformations: find and replace (literal or regex), replace whitespace with a hyphen, underscore, dot, or custom separator, change letter case (lowercase, UPPERCASE, Title Case, or Sentence case), add a prefix or suffix, insert sequential numbers as a prefix, suffix, or full stem replacement with configurable start, step, and zero-padding, and change the file extension (keep, lowercase, uppercase, replace with a specific value, or remove). The pipeline always strips the extension off the last segment before transforming the stem, then re-attaches it at the end, so .pdf, .csv, .docx, .jpeg, and any other suffix stays intact through every step. A live side-by-side preview shows the old name and the new name for every entry; rows turn amber whenever two outputs collide so you never silently overwrite a file when you apply the rename outside the browser. Sort the input list by A to Z, Z to A, shortest first, longest first, reverse, or keep the original order before numbering. Copy the new names on their own, copy a plain-text report with original-to-new pairs, or copy a ready-to-run Bash mv script, PowerShell Rename-Item script, or Windows cmd ren script so a list paste becomes an actual rename without writing the loop by hand. Useful for photographers prepping a shoot for delivery, podcasters numbering episodes, content engineers renaming exported assets to web-safe slugs, archivists migrating legacy folders to a consistent scheme, developers normalizing test fixtures, and anyone who has ever opened a folder of 200 files and wished a graphical tool could rename them with one rule. Everything runs locally; no filenames are uploaded or logged. Always test on a copy of your files first, and review the generated script before running it.

Free to use. Works in your browser. No signup, no login.