BatchRename

What is BatchRename?#

Renaming one file is easy. Renaming two hundred photos from IMG_4421.jpg, IMG_4422.jpg, IMG_4423.jpg… into 2024-08-15_paris_001.jpg, 2024-08-15_paris_002.jpg by hand is the kind of thing that takes a Saturday afternoon and gives you nothing but regrets.

BatchRename does it in about ten seconds. You select the files, stack a few rules (add a prefix, strip the camera's default name, insert a counter, fix the casing), watch the preview update live as you tweak, and only commit when the new names look exactly right. It replaces apps like A Better Finder Rename ($19.95/year) — except it's built into Seiz at no extra cost.

Opening BatchRename#

Select two or more files in any folder, right-click the selection, and choose Batch Rename… from the menu. A dialog window appears with two panels side by side: the rule list on the left, and a live preview of what your file names will look like on the right.

Nothing on disk has changed yet. You can play with rules freely — add them, remove them, reorder them — and the preview updates immediately. Files only get renamed when you click the Rename button at the bottom.

The Nine Rule Types#

Rules are the building blocks. Add as many as you want from the Add Rule menu and they'll be applied in order, top to bottom — each rule receives the output of the one above it. Mix and match to get exactly what you need.

Find & Replace#

Replace one piece of text with another. By default it's a literal, case-sensitive match — so “IMG_” only matches “IMG_”, not “img_”. Tick the Regex box for pattern matching when you need it (advanced users only — if you don't know what regex is, you don't need it).

Add Prefix / Add Suffix#

Adds text to the start or end of every file name. The file extension (the bit after the last dot, like .jpg) is always left alone — a suffix gets inserted before the extension, not after, so photo.jpg + suffix “_edited” becomes photo_edited.jpg, not photo.jpg_edited.

Numbering#

Appends a sequential number to each file: photo_001, photo_002, photo_003. Three knobs you can tweak: start (what the first number is, default 1), step (how much to increment, default 1), and padding (how many digits, default 3 — so “1” becomes “001”).

Change Case#

Eight options: UPPER CASE, lower case, Title Case, camelCase, snake_case, kebab-case, PascalCase, and SCREAMING_SNAKE. Useful for normalizing a folder of inconsistently-named files into a single style.

Date Stamp#

Adds a date to the file name — but here's the trick: for photos, BatchRename uses the actual date the photo was taken (extracted from the EXIF metadata your camera embedded), not the file's last-modified date. So if you copied a photo around between drives last week, the date stamp still reflects when you pressed the shutter, not when macOS last touched the file.

For non-photo files, it falls back to the file's modification date. Six format options — 2024-08-15, 20240815, 2024-08-15_143022, 20240815_143022, 2024-08, plus a Custom field where you can specify any date format you want — and three positions (prefix, suffix, or replace the whole name with the date).

Remove / Strip#

Cleanup operations that don't fit Find & Replace: remove a substring (literal or regex), strip leading/trailing whitespace, remove special characters, or truncate to a maximum length. Useful when you're dealing with messy names from web downloads or old backups.

Extension Rename#

Operations that target the file extension specifically (the part after the last dot — every other rule deliberately leaves this alone): normalize case, rename one extension to another (e.g. .jpeg → .jpg), remove the extension entirely, or add one if it's missing.

Add Metadata#

Inserts file metadata into the name. For images, that means EXIF fields like camera model, lens, ISO, image dimensions, or GPS coordinates. For music files: artist, album, title, track number. For video: duration, width, height. Pick the field, the position (prefix or suffix), and a separator string. Useful for organizing media libraries by equipment, album, or shoot details.

The Live Preview#

The right panel shows every file with its current name on the left and the new name on the right, updating instantly as you adjust rules. This is the safety net — you can see exactly what's about to happen before you commit, including subtle issues like unexpected double underscores or missing characters.

Hitting Rename#

Click Rename. Each file gets renamed sequentially, files whose name wouldn't change are skipped, and the status bar shows a quick “Renamed N files” confirmation. The dialog closes and you're back in the file list with the new names already in place.

Unlike most file operations in Seiz, batch renames are not undoable through ⌘Z. The live preview is your safety net — once you commit, the names are committed. That said, the files themselves are completely unchanged: only their names are different, so if you mismetered something you can always run BatchRename again to fix it.

Saving Rule Sets as Presets#

Once you've built a stack of rules that does exactly what you want, click Save Preset in the dialog and give it a name. Next time you open BatchRename, click Load Preset to restore the whole rule chain in one click. Useful when you do the same kind of rename across different folders all the time — like the photo-import workflow below.

A Few Useful Recipes#

Some common combinations that come up a lot:

• Photos from a trip: Find & Replace (find “IMG_”, replace with nothing) → Date Stamp (EXIF, prefix) → Add Prefix (“paris_”) → Numbering (padding 3). Result: 2024-08-15_paris_001.jpg, etc.
• Scanned documents: Add Prefix (“invoice_”) → Numbering (start 100, padding 4). Result: invoice_0100.pdf, invoice_0101.pdf, etc.
• Cleaning up download names: Find & Replace (find “%20”, replace with space) → Change Case (Title Case). Turns annual%20report%202024.pdf into Annual Report 2024.pdf.
• Organizing screenshots: Find & Replace (find “Screen Shot ”, replace with nothing) → Add Prefix (“screenshot_”). The original macOS naming is verbose — strip it and add your own prefix.

Next Steps#

• SmartFolder — find duplicate files and the biggest space hogs on your Mac.
• Multi-Pane Layouts — source folder on the left, destination on the right, drag files between them.
• Keyboard Shortcuts — keyboard-driven file management across Seiz.