Give two files a shared stem and sequence
Input and settings
Synthetic alpha.txt (3 bytes), beta.csv (5 bytes) / Stem report / Start 7, three digits
Expected result
report007.txt and report008.csv. ZIP entries retain the original three/five bytes.
Batch File Renamer
Preview new names for multiple files and save renamed copies in a ZIP, preserving every original byte. Original files are unchanged.
How to use
- Choose the files to save under new names.
- Set the naming mode, prefix, suffix and numbering, then inspect the mapping.
- Create and save the ZIP, then inspect extracted names and contents.
Files and naming options
Drop multiple files here.
1–100 files; 40 MB per file, 80 MB combined, 96 MB ZIP output. Names: at most 240 UTF-8 bytes.
Save
How to use and limits
Choose files, set naming options and review every new name. Use Up, Down and Remove to adjust the list, then create and save the ZIP.
The extension starts at the last dot: archive.tar.gz keeps .gz. Dotfiles such as .env have no extension. Removing an extension does not convert the content or format.
New names are checked for collisions, including case and Unicode normalization. Paths, control characters, Windows reserved names, incompatible symbols, leading or trailing spaces and trailing dots are rejected. Folder structures are not preserved.
Original files are unchanged. Every byte is copied into an uncompressed ZIP under the new names; file sizes are not reduced. Cancel, option changes and file changes discard the previous export. Files and names are processed locally and are neither stored nor sent.
Try a use case and check the result
Preview names and verify bytes before saving renamed copies in a ZIP.
Example buttons replace the inputs and settings above and calculate. Restore previous input steps back one example at a time. After trying multiple examples, repeat restore to return to your original input. This history is lost when the page closes.
Distinguish a compound extension and a dotfile
Input and settings
Synthetic archive.tar.gz, .env / Prefix copy_ / No numbering / Keep extension
Expected result
copy_archive.tar.gz and copy_.env. Format is unchanged; only the final dot separates an extension.
How to read the result
Examples temporarily use tiny synthetic files and create a ZIP. Undo restores your list, order and settings; recreate the ZIP afterward. Changing an extension does not convert the format. Reordering changes sequence assignment.
Scope and limits
1–100 files; 40 MB each, 80 MB combined, 96 MB ZIP; names up to 240 UTF-8 bytes. Case/Unicode-normalized collisions, reserved names and paths are rejected. Examples wait during reads/creation; restoring during a read also waits. No folder preservation or compression size savings. Original files are never directly renamed.
Independently unzip and compare entry names and every byte. Restore a nondefault order/options after both examples, verify recreated output, cancellation and stale worker replies.
Continue with the next task
Frequently asked questions
Are original files renamed?
No. Renamed copies are saved in a ZIP.
What happens when names collide?
ZIP creation is blocked. Adjust the options or file order.
Does changing an extension convert the file format?
It creates renamed copies without converting their contents or bytes. Use a suitable conversion tool to change the format.
Related tools
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