Batch File Renamer

What does this tool change?

It changes only the filename used for the download, not the file contents. A photo keeps its resolution and a document keeps its content while the name follows the pattern you choose.

• Your browser only reads the original files.
• Check each new filename in the preview table first.
• Save the downloaded results to the folder you want.

Use it in screen order

Drag files into the drop zone or use Add files. Once they appear in the queue, choose naming rules and compare the old and new names in the preview table. When everything looks right, download the selected files.

1. Build a file queue
2. Choose naming rules
3. Check the preview and warnings
4. Download files individually or as a ZIP

How naming rules work together

Keep the base name or replace it with a custom one, then add a prefix and suffix. Space handling, letter case, numbering, and extension options are applied in that order.

• Prefix: add a date, project name, or location at the start
• Suffix: add a status such as final, draft, or shared at the end
• Numbering: preserve a clear sorting order
• Extension: standardize mixed forms such as JPG and jpg

Why check both the queue and preview?

The queue shows which files are included and the individual download state. The preview table lets you compare original and new names row by row. Looking at both helps catch mistakes when the queue is long.

• Queue: confirm that the files were added
• Preview: confirm the naming pattern is right
• Status: check for duplicates or invalid characters

Why use number padding?

When filenames are sorted alphabetically, 1, 2, and 10 may not appear in the order you expect. Matching the digits as 001, 002, and 010 keeps the order steady in most file managers.

• Two or three digits leave room when you add files later.
• It is useful for photo sequences, course materials, and delivery files.
• Change the starting number to begin at 000 or 101.

An example

For three travel photos, a date-and-location rule can create the preview below. Download a ZIP when you need all three, or use the queue to download just one or two.

When do duplicate names and invalid characters occur?

Using the same custom name for every file with numbering off can create duplicates. Some operating systems also do not allow /, \, :, *, ?, ", <, >, | in filenames.

• Duplicates are checked among the files you selected.
• Turn on invalid character removal to strip common problem characters.
• Letters, numbers, spaces, underscores, and dashes are generally kept.

Individual downloads and ZIP downloads

With one selected file, the tool downloads it right away with its new name. With several selected files, it bundles them into one ZIP. Use the individual download button in the queue when you need a specific file again.

• One file: a single download with the new name
• Several files: one roberin-renamed-files.zip download
• Queue button: save one specific file separately

Why are the originals not overwritten?

A webpage cannot directly rename files in your local folders under the browser security model. Instead, it downloads selected files with new names. That protects the originals and makes it easy to start over after a mistake.

• Your original folder is not changed.
• New files appear in your downloads folder.
• Review the results, then keep or organize the originals.

Common pitfalls

Removing an extension can cause trouble where software relies on it to identify the file type. Unless you have a specific reason, keeping extensions or converting them to lowercase is usually safer.

• Files without extensions can be harder to open.
• Giving multiple files the same name can cause overwrite confusion.
• A custom name without numbering raises the risk of duplicates.

How this differs from built-in batch rename

macOS Finder and Windows File Explorer include basic renaming features. This page focuses on combining rules in a browser without installation, then checking download results without touching the originals.

• Use it without installing a tool.
• Do not change the original folder directly.
• Handle preview and ZIP download on one screen.

Final check before downloading

Check the purpose, numbering, extension, and duplicate warnings once more before downloading. For files you share with others, make sure the date, version, and order are clear from the filename.

• Are the new names too long?
• Does the numbering match the actual file order?
• Did you keep the extension?
• Are any duplicate warnings left?

Decide these before you write the rule

Renaming is easy to do and tedious to undo. Settling these four points before you type a rule keeps you from running the batch twice.

• What will you search for later — put the date, project name or product code first
• Does sort order matter — if it does, add numbering with one digit more than the file count needs
• Will the files be shared — then use hyphens or underscores instead of spaces and avoid non-Latin names
• Where do the originals live — keep the source folder for at least one cycle after downloading the renamed copies

Common failures and what to do about them

Catching these in the preview table is much cheaper than sorting them out after download.

• Numbers sort as 1, 10, 11, 2 — the digit count is too low. Raise it to three or more
• The same name appears on several rows — turn numbering on or add a distinguishing suffix
• The ZIP contains names with an unexpected number appended — you archived duplicates. Resolve them first
• The extension ended up inside the name — you typed a dot in the rule. The tool keeps the extension, so leave it out
• Files will not open on another machine — a forbidden character or an over-long name. Keep the full path under about 200 characters

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