Document Format Comparison

PRC vs MOBI — Palm vs Mobipocket E-book Formats

PRC and MOBI are essentially the same format — both are Mobipocket-compatible e-book containers. PRC was the original Palm OS file extension; MOBI became the standard with the Mobipocket reader. Many books distributed in the early 2000s use the .prc extension; later books use .mobi. The internal structure is identical for most files.

PRCvsMOBI

Quick Verdict

Use PRC when…

PRC is legacy — convert to EPUB or AZW3 for modern reading. The .prc extension is rare in 2026.

Use MOBI when…

MOBI is also legacy. Amazon stopped accepting MOBI submissions in 2022. Convert to EPUB or modern AZW3.

PRC vs MOBI: Feature Comparison

Feature	PRC	MOBI
Origin	Palm OS (1996+)	Mobipocket (2000+)
File extension	.prc	.mobi
Internal structure	Same as MOBI (mostly)	Mobipocket format
DRM	Mobipocket DRM	Mobipocket DRM
Modern device support	Limited	Limited (legacy Kindles)
Conversion target	EPUB or AZW3	EPUB or AZW3

When PRC wins

✓Origin: Palm OS (1996+)
✓File extension: .prc
✓Internal structure: Same as MOBI (mostly)

When MOBI wins

✓Origin: Mobipocket (2000+)
✓File extension: .mobi
✓Internal structure: Mobipocket format

Frequently asked questions

Are PRC and MOBI interchangeable?

Yes for most files. Calibre and other e-book tools handle both extensions identically. Some old PRC files use Palm DOC format internally (different from MOBI), but those are rare in 2026.

Can I rename .prc to .mobi?

Usually yes, since most .prc files are MOBI-compatible. If your reader rejects the renamed file, convert with Calibre instead — pick the format that opens correctly.