Filenames and contents are not sent to any server.
What you can do with the batch file rename and ZIP organizer tool
You can add sequential numbers or dates to multiple filenames, replace common text, normalize full-width spaces, and unify case or extensions. Compare before and after in a list, and if satisfactory, save the renamed files as a ZIP.
When loading a ZIP, you can choose from four organization methods: maintain the folder structure, flatten to one level, keep only the top-level folder, or classify into images, documents, spreadsheets, archives, and others. Management files auto-generated by macOS or Windows are excluded, and dangerous relative paths are also excluded from saving.
Sequential numbers, dates, and text replacement
Set start number, increment, digits, position, and modification date or specified date to match your naming conventions.
Check forbidden characters and duplicates
Fixes characters not allowed in Windows, reserved names, trailing spaces and dots, and prevents overwriting files with the same name.
Organize folders inside the ZIP
Choose keep hierarchy, flatten, top-level folder, or type-based classification, and save as an organized ZIP.
CSV / PowerShell output
Save the full before/after list to CSV and generate a Windows command to rename the actual files.
Steps to batch rename multiple files
- Choose files or foldersDrag and drop, or use the file/folder selection buttons to load targets.
- Set change methodSet prefix/suffix, find and replace, whitespace, letters, extensions, numbering, and dates.
- Review the list of changesCompare original names and destinations, and check the “Corrected,” “Needs Review,” and “Excluded” labels.
- Save in a format that suits your purposeSave as ZIP to safely receive renamed files, or CSV if you only need a record.
- Use the command only when modifying files directly in the original folderReview the PowerShell content and target folder, and keep a backup before running.
The preview updates with each setting change. No new ZIP is created until you press the save button, and the selected original files are never overwritten. For large batches, first test the naming rule with about 10 items before processing all.
Add sequence numbers like 001, 002
Enable “Add sequential number,” set the starting number to 1, increment to 1, and digit count to 3 to get 001, 002, 003. With a starting number of 100 and increment of 10, you get 100, 110, 120. The position of the number can be at the beginning or end of the filename.
| settings | before | after | use |
|---|---|---|---|
| 3 digits, prefix | Invoice.pdf | 001_Quote.pdf | Documents that need a fixed order |
| 4 digits, suffix | product_image.jpg | Product_Image_0001.jpg | Product images and photo data |
| Start at 100, increment by 10 | process.txt | 100_process.txt | Steps where numbers may be inserted later |
| Template | report.docx | 20260828_Report_001.docx | Management documents with dates and numbers |
The order is the order loaded. The display order in the file selection screen may vary by OS and browser. If the correspondence between numbers and original files is important, check the order in the preview or the change list CSV.
Normalize spaces, letter case, and file extensions
File names copied from different systems may contain non-breaking spaces, full-width compatibility forms, or inconsistent capitalization. Normalize them only when your destination requires it, then verify every preview before saving.
NFKC normalization can change compatibility characters, so disable it when exact Unicode spelling is part of a record or archive requirement. Changing an extension’s letter case does not convert the file format.
Normalize spaces, letter case, and file extensions
File names copied from different systems may contain non-breaking spaces, full-width compatibility forms, or inconsistent capitalization. Normalize them only when your destination requires it, then verify every preview before saving.
NFKC normalization can change compatibility characters, so disable it when exact Unicode spelling is part of a record or archive requirement. Changing an extension’s letter case does not convert the file format.
Fix file names that won’t work on Windows in advance
On Windows,< > : " / \ | ? * and control characters cannot be used in filenames. Also, CON, PRN, AUX, NUL, COM1–COM9, and LPT1–LPT9 are reserved names and may cause issues even with an extension. Trailing spaces and dots are also unstable.
This tool replaces forbidden characters with underscores, hyphens, or empty strings, and adds an underscore to the beginning of reserved names. If the name becomes empty after replacement or deletion, “Untitled” is used. If the filename is too long, it is shortened to 255 characters, keeping the extension.
| issue | example input | adjustment example | Reason for confirmation |
|---|---|---|---|
| Forbidden characters | Quote_Final?.pdf | Quote_Final_.pdf | Exclude characters that cannot be created on Windows |
| reservation name | CON.txt | _CON.txt | Avoid Windows device reserved names |
| Trailing dot | Document . | documents | Avoid issues where names change between OSes |
| Name is empty | delete_target.txt | untitled.txt | Avoid names that are only extensions |
Even if the destination is not Windows, aligning to Windows-compatible names when sharing via email attachments, cloud storage, or internal systems reduces issues. Each service has its own length limits and forbidden characters, so also check the final destination’s specifications.
Prevent overwriting when duplicate filenames occur
Flattening folders to one level can bring files with the same name from different folders to the same destination. Also, text replacement or space deletion can make different names identical. Since Windows typically treats names differing only in case as the same, this tool detects duplicates without case sensitivity.
By default, ” (2)” and ” (3)” are added to subsequent items to avoid overwriting. Choosing “Stop on error” disables ZIP saving while duplicates remain. If your internal naming rules do not allow automatic numbering, add prefixes, department names, dates, etc., while viewing the error messages.
How to organize folders inside a ZIP
For ZIP organization, the compressed file is not uploaded to a server; its contents are read in the browser’s memory. The filenames, relative paths, sizes, and modification dates are listed, and after reviewing the new structure, a separate ZIP is created. The original ZIP is not modified.
| Organization method | Changes | Best use cases | caveats |
|---|---|---|---|
| Keep current hierarchy | Keep the folder structure and change only names | Project materials, web assets, delivery data | Deep hierarchies or long paths may be limited by the destination. |
| Flatten to one level | Remove folders and place all files directly under the root | Photos, receipts, and data handled in lists | Duplicate files are more likely, so check the duplicate display. |
| Keep only the top-level folder | Keep only the top-level category like department or project | Shared documents to flatten | If duplicate names exist in deeper levels, numbers are used to avoid conflicts. |
| by type | Classify into images, documents, spreadsheets, archives, and other | Organize received files and downloaded materials | Classification is based only on file extensions, not content. |
In type-based organization, jpg, png, webp, etc. go to “Images”; pdf, docx, pptx, txt, etc. to “Documents”; xlsx, csv, tsv, etc. to “Spreadsheets”; and zip, 7z, rar, etc. to “Archives.” The classification is based on the extension, so files with incorrect extensions or no extension go to “Others.”
Exclude dangerous paths that could lead to ZIP Slip and junk files
For ZIP,../ may contain parent folder references or absolute paths with drive names or leading slashes. Depending on the extraction software, this can cause “ZIP Slip,” writing files outside the intended extraction location. This tool does not include such paths in the new ZIP and displays the exclusion reason.
Often included in ZIPs created on macOS__MACOSX Folders and.DS_Store, WindowsThumbs.db anddesktop.ini are usually unnecessary management information for deliverables. They are excluded by default. In special cases where they have business meaning, disable the exclusion and check the preview.
This tool does not perform virus scanning. ZIPs from unknown senders, ZIPs containing executables, and password-protected ZIPs should be handled according to your organization’s security policy and antivirus products. Decryption of password-protected ZIPs is not supported.
How to use the filename template
Use templates when combining multiple elements in a fixed order.{date}_{folder}_{name}_{n:3} enters the date, the immediate parent folder name, the formatted original name, and a 3-digit sequential number in order. If a template is entered, it takes precedence over adding to the beginning/end and individual position settings for numbering and dates.
| symbols | Content to insert | e.g. | note |
|---|---|---|---|
{name} | Name reflecting the space, replacement, and letter settings | quote | Does not include extension. |
{original} | Original filename stem | Invoice | For keeping the pre-normalization notation. |
{n} / {n:4} | Configured sequence number / sequence number with specified digits | 001 / 0001 | Applies the starting number and increment. |
{date} | Date in selected format | 20260828 | Uses the modification date or a specified date. |
{yyyy} {yy} {MM} {dd} | Year, month, day | 2026, 26, 08, 28 | Use for custom separators. |
{folder} | Name of the folder directly before the original file | Sales Dept. | For a single file, this becomes an empty string. |
If the template contains symbol typos, those characters remain in the filename. Check the preview before saving to ensure the intended name.
How to use the change list CSV
The change list CSV includes all items: original path, new path, size, status, and notes. The on-screen preview shows only the first 300 items to reduce load for large batches, but the CSV includes all items, including excluded ones.
The CSV is saved with UTF-8 BOM to avoid garbled text in Excel. It can be used for internal approval, pre-delivery checks, renaming history records, and division of labor between the person performing and the person checking. Saving the CSV does not include the contents of the original or new files.
To rename original files directly with Windows PowerShell
Browsers cannot directly rename arbitrary local files selected by the user without permission. Therefore, this tool can output a PowerShell command that targets only files in the same folder. Files in subfolders or inside ZIPs are not covered.
The generated command renames each file to a unique temporary name before the final name to avoid collisions even with swaps or cycles. Single quotes in filenames are escaped for PowerShell.
- Back up the target folder before running.
- Check the copied content in Notepad or similar, and verify the target file names and count.
- Navigate to the target folder in PowerShell before running.
- For syncing cloud folders, wait for sync to complete before processing.
- Do not run in locations requiring permissions, system folders, or shared files.
If you are unsure about running the command, use “Save modified ZIP,” verify the extracted contents, then replace the original folder.
In-browser processing and file safety
The selected filenames, file contents, and ZIP contents are not sent to WiseChecker’s processing servers for conversion. Creating the file list, converting names, reading and recreating the ZIP, and generating the CSV and PowerShell are all done in the browser where the page is open.
The HTML, CSS, and JavaScript needed to display the page are loaded from the website, but the tool’s program does not include communication to transfer selected files externally. Reloading or closing the page discards the selected list and settings.
Even with on-device processing, the browser’s memory and the destination’s free space are used. The limit is 5,000 items and 1 GB total; more is not loaded regardless of device performance. ZIPs of several hundred MB or thousands of files may take time depending on the PC’s memory, so splitting is recommended. On smartphones, process in even smaller batches.
Supported browsers and limitations
- Latest versions of Google Chrome, Microsoft Edge, Firefox, and Safari are recommended.
- Folder selection is available in supported browsers like Chrome and Edge. If unsupported, select multiple files instead.
- Password-protected ZIP, 7z, and rar files are not supported for reading. 7z and rar files inside a ZIP are only classified into type folders.
- Does not convert file formats, compress images, edit PDFs, or scan for viruses.
- Symbolic links, permissions, and extended attributes in ZIPs may not be preserved exactly.
- File name display and saveability vary by OS, destination, and cloud service specifications.
Frequently asked questions about batch renaming files
Will the selected original files be changed automatically?
They are not changed. The new names are calculated in the browser and saved as a separate ZIP. Only if you want to directly modify the original files, review and use the generated PowerShell command.
Can I start numbering at 1001 instead of 001?
Yes. Set the starting number to 1001. The digit count is the minimum display width, so numbers exceeding 4 digits are not truncated.
Can I delete specific characters from filenames?
Enter the text to search for and leave the replacement blank. Choosing “Normal text” searches for symbols literally. Use regular expressions only for complex conditions.
What happens if there’s an error in the regular expression input?
Errors are shown at the top of the preview, and ZIP saving is disabled. Original files are not modified. If normal text replacement suffices, choose “Normal text” for safety.
Can I change only the name while keeping the extension?
Yes. The part after the last dot is treated as the extension and separated; replacement, numbering, and dates are applied only to the name part. The extension can be kept as-is, lowercased, or uppercased.
Will files with the same name be overwritten?
No overwriting. By default, (2), (3) are added to subsequent items. If “Stop on error” is selected, ZIP saving is disabled until duplicates are resolved.
Can I keep the ZIP folder structure as is?
Choosing “Keep current hierarchy” preserves the original relative paths and only renames files. Folder names with forbidden characters are corrected to safe characters.
Can I remove junk files from a ZIP created on a Mac?
By default, __MACOSX and .DS_Store are excluded. Windows Thumbs.db and desktop.ini are also excluded.
Are ZIP contents and file names sent to a server?
Nothing is sent. Loading, previewing, and recreating the ZIP happen in your browser. Closing the page discards your selection.
Can I use it on a smartphone?
It works, but folder selection and large ZIPs may be limited by the device and browser. For large batches, we recommend the PC version of Chrome or Edge with ample memory.
Does the CSV include rows not shown on screen?
Yes. The screen shows the first 300 items, but the change list CSV includes all items, including excluded ones.
Can opening a ZIP cause the original files to disappear?
None. The original ZIP is read-only, and a new ZIP is saved as a separate file. It remains unless you delete or overwrite the original file at the destination.
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