When the preview or the publication are launched, PubCoder executes a specific check action in order to validate your project for the selected format. In particular, the ePub is submitted to two specific checks: the first one checks that certain requirements set by Apple are satisfied (for example: Images cannot be larger than 3.4 million pixels), the second one verifies the ePub using “epubcheck”, a tool provided by IDPF to validate the ebook.


The KF8 is generated by KindleGen, a tool provided by Kindle, that generates and validates .mobi files.


At the end of the process, if alerts appear, PubCoder will open a window displaying all the error notifications and alerts.

PubCoder allows you to proceed in any case, even if some errors do appear.
Should you proceed without correcting at least these errors, the file will be rejected by the store and not published.