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Batch Rename

Combine rules to rename files in bulk. Check old → new names live, catch duplicates and invalid names, then save renamed copies as a ZIP or into a folder. Files are never uploaded.

On-device・No upload

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

Files are processed in this browser on your device and never uploaded.

Drop files here (multiple allowed)

or

Accepts: Any file typePaste (Ctrl+V) also works
Rename rules1 / 1
  1. Find & replace

    Replace text or a regular expression (use $1 for groups).

Presets0

Only the rules are stored in this browser — never any file information.

How to use

  1. Drop files or use “Choose files” / “Choose folder” (or click “Try a sample”).

  2. Add rules — find & replace, numbering, date, case, extension, clean-up, remove characters. They apply top to bottom; reorder them with the arrows.

  3. Check “current → new name” in the preview. Changing the order (natural, modified time, size…) also changes the numbering.

  4. If duplicates or invalid names appear, fix the rules or turn on automatic resolving.

  5. Click “Download ZIP”, or in supported browsers “Save copies to a folder”. Save rule sets you reuse as presets.

What it does

Eight rule types, freely stacked

Find & replace (regex with $1 groups), prefix/suffix, numbering (start, step, digits, position), dates, letter case, extensions, whitespace and full-width clean-up, and removing characters by count — in any order.

Invalid names caught before saving

Windows reserved names (CON, NUL, COM1…), forbidden characters \ / : * ? " < > |, trailing dots or spaces, names over 255 bytes and duplicates that differ only by case are flagged in the preview.

Name photos by capture date

The date rule can use the file’s modified time or the photo’s EXIF capture time (DateTimeOriginal), read on your device only when needed.

Natural sorting and numbering

Sort naturally (2 before 10), by modified time, size or the order added, then number. Numbering can restart in each folder.

Presets for your rules

Save rule combinations by name in this browser. Only the rules are stored — never file names or contents.

Use cases

  • Turn camera names like “IMG_0001.JPG” into “2024-05-01_trip_001.jpg”
  • Remove full-width spaces and “final (1)” clutter from documents before sending them
  • Pad sequence numbers so files sort correctly in Explorer and Finder
  • Unify “.JPEG” and “.Jpg” extensions to “.jpg”
  • Restart numbering at 001 in every folder

Supported formats

Input

Any file type (multiple files or a whole folder)

Output

ZIP of renamed copies (folder structure optional)Renamed copies written into a chosen folder (Chrome, Edge…)rename-log.csv with old and new names

Capability matrix

FeatureSupportNotes
Find & replace (regex, case-sensitive option)Supported—
Numbering, dates (modified / EXIF), prefix and suffixSupported—
Case, extension, whitespace and full-width clean-upSupported—
Detect and resolve duplicates, reserved names, invalid characters, lengthSupported—
Rule presets (stored in the browser)Supported—
Rename the original files on your computer in placeNot supportedA browser limitation — renamed copies are saved instead
Write copies into a chosen folderPartialOnly in browsers with the File System Access API (Chrome, Edge…)
Save everything as a ZIPPartialUp to 2 GB in total
Drag & drop whole foldersNot supportedUse the “Choose folder” button

Limits & notes

  • Up to 5,000 files at a time.
  • ZIP output is limited to 2 GB in total; use “Save copies to a folder” for more.
  • Browsers cannot rename your original files. The output is renamed copies; originals stay untouched.
  • “Save copies to a folder” skips files whose name already exists — nothing is overwritten.
  • A regular expression that runs longer than 2.5 seconds is stopped so the page doesn’t freeze.

Privacy & safety

Reading files, renaming and zipping all happen inside your browser. Files and file names are never sent to a server. Presets store only the rules.

FAQ

Why aren’t my original files renamed?
Web browsers have no permission to rename existing files on your computer. This tool saves renamed copies as a ZIP or into a folder; delete the originals yourself if you no longer need them.
Can it sort “IMG_1, IMG_10, IMG_2” correctly?
Choose “Name (natural)” as the order: numbers are compared as numbers, so 1 → 2 → 10. Then set the numbering rule to 3 digits for names that sort correctly everywhere.
How do I use regular expressions?
Turn on “Regular expression” in a find & replace rule. For example find ^IMG_(\d+)$ and replace with photo-$1 to turn “IMG_0012” into “photo-0012”. Mistakes are shown under the rule.
Which file names are invalid on Windows?
Reserved names such as CON, PRN, AUX, NUL, COM1–9 and LPT1–9, names containing \ / : * ? " < > |, and names ending with a dot or space. The preview flags them, and automatic resolving replaces them with safe names.
Where are presets stored?
Only in your browser (localStorage). Nothing is sent to a server, and only the rule settings are saved. Clearing browser data removes them.

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