About this tool
Add a project name, date, or other prefix to a group of files. The prefix goes at the beginning of the base name without duplicating the extension. File contents stay unchanged.
How to use
- Select one or more files.
- Enter a prefix, such as holiday_ or final-.
- Review the name preview and any conflict warnings.
- Download a single copy or a ZIP.
Features
- Combines document.pdf with final- to create final-document.pdf.
- Preserves ordinary and common compound extensions.
- Checks names before creating a local download.
Prefixes and extensions
- Your browser does not modify the original files on your computer. This tool creates downloadable files with new names.
- Recognizes common compound extensions such as .tar.gz, .tar.bz2, .tar.xz, .user.js, .min.js, .min.css, and .d.ts by default. Other names use the part after the last dot as the extension.
- The prefix is added only to the beginning of the base name. It does not change or duplicate the extension.
Limits
- Select up to 1,000 files at a time. When downloading multiple files as a ZIP, their combined original size must not exceed 100 MiB.
- Filenames must not include folder paths. Adjust the rules if a name is too long, empty, or conflicts with another name.
- File contents stay unchanged; only the download name or ZIP entry name changes. Keep your originals and check the preview.
Privacy
All files are processed only in your browser and are never uploaded to a server.
File names, entered text, and results are processed only in your current browser. Your input is not saved automatically. Download any results you want to keep before clearing the tool or leaving the page.
FAQ
Where is the prefix added?
It goes at the start of the base name, before the extension. For example, adding holiday_ to 001.jpg creates holiday_001.jpg.
Will the extension be added twice?
No. The original extension is preserved separately. Adding a prefix will not turn document.pdf into document.pdf.pdf.
Can the browser rename the original files on my computer?
No. This tool creates downloads with new names. Your original files are not renamed, moved, or overwritten.
How do I get the processed files?
Review the original and new names first. Download a single file directly, or download multiple files as a ZIP and extract the renamed copies.
Will the file contents change?
No. Renaming only changes the download name. The original bytes are preserved: images are not re-encoded, and text encoding is not changed.