Why is my WOFF font larger than the TTF font?

Question

From my understanding (source), a WOFF format is basically a compressed OTF/TTF font.

If that is really the case, then why is my WOFF font bigger than my TTF font as seen in the screenshot below.

The fonts were generated using the popular Icomoon.io service.

Has anyone else noticed similar results in their fonts?

Thx

Answer 1

Assuming the woff file was built correctly according to the specification (which doesn't allow for the compressed font tables to be larger than the original tables), the size increase can be attributed to the inclusion of extended metadata and/or private data.