I find this app very slow to convert from pdf to ePub, is it outdated?

I looked at alternatives on the web, however they all seem like ads, pushing their products for financial incentive rather than if they truly perform better.

That’s why I’m asking here, as you may have tried a different app that was faster and will probably not have a financial incentive. Any ideas?

  • Cross-posted as apple.stackexchange.com/questions/421343/…
    – nohillside
    May 28, 2021 at 12:38
  • have you tried using the command-line converter built into calibre to see if that is any faster than using the GUI? see here: askubuntu.com/questions/169618/… May 29, 2021 at 21:28
  • Is it supposed to be faster? I actually prefer the terminal @DeveloperACE
    – Nickotine
    May 30, 2021 at 7:28
  • @developerACE you are the man! Using GUI convert for the same pdf book it took 1hr 47 mins, using the cmdline it took 37mins what an extreme difference… I used the time cmd thank you so much and the converted ePub works fine
    – Nickotine
    May 30, 2021 at 8:45
  • Awesome, ill post that as an answer so it can be accepted to let others know that this has a solution now May 31, 2021 at 20:48

1 Answer 1


I have come across another post on askubuntu that's also looking for a calibre alternative.

The accepted answer on that post basically suggests using calibres internal command line tool:

The Calibre install provides the command ebook-convert that will handle what you want, and there's no need to run Calibre.

ebook-convert file.pdf file.epub

The original answer goes into more detail in case that doesnt work as well.

If this does produce a meaningful speed difference compared to the GUI, then there's a chance this may be the result of a setting, or possibly a bug that could be causing the extra slowness.

My initial suspicion is that maybe the GUi could be defaulting to the "smart convert" that was mentioned in the askubuntu post. If you are interested in getting to the cause of this and possibly fixing the GUI, maybe try the command-line smart convert to see if its the GUI, or the "smartness" that's the cause of the slowness.

I suspect if the smart convert is at fault, there may be a setting to disable this or make it not the default when using the GUI. If its only slow in the GUI, then it may be a bug and might be worth checking the invormation on how to find an existing report for this or file a new report on the calibre bugs page in case it helps other users or the developers to find a fix.

  • I hate GUIs anyway, I do nearly everything on the terminal
    – Nickotine
    May 31, 2021 at 21:13

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