File Name vs File Extension: What You Need to Know

Before bulk renaming files, understand the difference between names and extensions.

What is a File Extension?

The file extension is the part after the final dot:

document.pdf
         ^^^
         extension

Common extensions: - .jpg/.jpeg - Photos - .png - Images with transparency - .pdf - Documents - .docx - Word documents - .mp4 - Videos - .mp3 - Audio

What is a File Name?

Everything before the extension:

my-document.pdf
^^^^^^^^^^^
file name

Can You Change File Extensions?

Yes, but be careful.

Changing the extension doesn't convert the file—it just changes what program opens it.

✅ Safe: .jpeg → .jpg (same format) ❌ Dangerous: .jpg → .png (doesn't actually convert) ❌ Broken: .pdf → .jpg (file won't open)

Can You Change File Names?

Yes! This is safe.

Changing the file name doesn't affect the file content:

IMG_5847.jpg → sunset-beach.jpg ✅

The image is exactly the same, just named differently.

Safe Renaming with Extensions

Keep the Extension When renaming, preserve the original extension:

IMG_5847.jpg → sunset-beach.jpg ✅

Standardize Case Most systems prefer lowercase extensions:

PHOTO.JPG → photo.jpg ✅

Standardize Format Some extensions are equivalent:

photo.jpeg → photo.jpg ✅

How File Renamer AI Handles Extensions

File Renamer AI safely handles extensions: - Renames the file name only - Preserves the original extension - Optionally standardizes .jpeg → .jpg

Your files stay functional, just better named.

Try File Renamer AI - Safe, smart renaming.