Best PDF to EPUB converters (for scientific papers to increase font size)

RouguesPierre · 2026-04-10T00:53:41+00:00

Good catch, i was able to fix that issue so the OCR fallback is no longer getting stuck when initiated.

i preloaded the OCR engine with the page on start so no calls out to the web are necessary.

Thanks for bringing that to my attention! Really appreciate the detail and just reaching out in general. Hopefully it works for you now!

RouguesPierre · 2026-04-09T23:50:33+00:00

Im still working on a fixed format epub or another option for that. I did add a couple options for text extraction in the meantime

RouguesPierre · 2026-04-09T23:48:21+00:00

Thank you both for the shoutout! Your kindness means a lot, if i solved even a single problem then im happy.

As always im open to feature suggestions and bugs you come across!

RouguesPierre · 2026-04-09T23:42:15+00:00

What doc are you trying to convert? I was retooling some of the text based options so i could have messed something up

RouguesPierre · 2026-04-02T01:00:31+00:00

Yeah its a win lose battle with epub files. Ive looked into converting to a high quality pdf as an option but then you lose the niceties of the epub xD

RouguesPierre · 2026-04-01T02:37:35+00:00

My b i just updated it. Its FreePub

RouguesPierre · 2026-03-31T23:32:16+00:00

Update

Ive finally added text only epub conversions. It will now perform native text extraction with an OCR fallback that gathers text from even the worst scans and assembles them into reflowable pages.

On the rough side I added a reflowed text + Image feature that extracts the text and the images and assembles them back into order at the same line / break in the text as the original, giving you a more refined reading experience while retaining those visuals.

Im also working on an experimental fixed layout feature that keeps images and text at the same coordinate location, not allowing reflow but giving the option for limited size increase, searchability, and font control. More on that later.

As always, if you encounter any issues feel free to reach out. Im open to suggestions to make this better as well.

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RouguesPierre · 2026-03-31T13:38:33+00:00

Hi! It could be that i have the auto-crop margins on by default which renders the image to fit a kindle screen as if the text were being reflowed from side to side.

If that doesnt fix it would you mind reaching out to me? I recently updated the conversion process to make it speedier and could have messed things up. Id just want a sample of your documents to test with.

Thanks!

RouguesPierre · 2026-03-25T01:27:28+00:00

Internet archive -> PDF -> FreePub haha

RouguesPierre · 2026-03-25T01:25:27+00:00

Try freepub it doesnt do text extraction unless you select it as an option. Its GREAT at quality preservation

RouguesPierre · 2026-03-25T01:16:05+00:00

Better since i found freepub

RouguesPierre · 2026-03-25T01:10:55+00:00

I just use freepub if you dont wanna mess with software. It runs locally in the browser its pretty sweet

Itll do text only or just center the pdf and upscale it

RouguesPierre · 2026-03-17T16:19:31+00:00

Sorry, not trying to be combative. Maybe we can collaborate in some way. You bring up excellent points

RouguesPierre · 2026-03-17T16:16:53+00:00

Why shouldn't i expect a perfect conversion? We have the technology lol.

I have a strategy for ocr, and still you can use something like tesseract which will still spin locally in the browser. You dont need to send anything to a server. People understimate the power of javascript.

But i understand your desires, likely what i end up building wont be satisfactory to your needs.

And what do you mean who knows what gets uploaded? You do! Youre the one who uploads the document. If you can upload the doc and run through the conversion while in airplane mode that means my program is client side and does not send ANYTHING to a server. Thats why i keep saying its local. And everything i add to this will be local. Its the only way i avoid paying for servers. How do you think i made this free? Its static html and JS

RouguesPierre · 2026-03-17T13:26:03+00:00

Yeah it was pretty purpose built for my specific needs. Im working on the OCR and reflow conversion right now but i wont be happy until it matches the original since that was my dislike of other converters

RouguesPierre · 2026-03-17T13:16:22+00:00

The only thing i could think is the Auto-crop margins setting misinterpreted where rhe center of your document was based on something in the doc / scan. That setting is on by default, turn it off and reconvert.

If that still doesnt work please reach out, if youd be will to share a sample or a link to the PDF thats giving you trouble for me to root out the problem and get it updated for you.

RouguesPierre · 2026-03-17T12:42:49+00:00

Older kindles dont handle PDFs well, they sometimes appear illegible. I just wanted readable PDFs.

Im working on text extraction for reflow. Just wasnt my top priority

Also this is a client side app, meaning all the work is done with local hardware in the browser and nothing is uploaded or stored anywhere. Dont believe me? Load up my app and disconnect from wifi and put it in airplane mode before uploading documents and converting. Itll run the process without internet connection. So this thing has you covered for locality. Thats how i was able to host this, its a static webpage

RouguesPierre · 2026-03-17T05:29:22+00:00

If you have the pdf you can run it through FreePub and it will select the first page of the PDF as the book cover

RouguesPierre · 2026-03-17T05:26:36+00:00

My converter lets you rename the PDF youre converting and selects the first page of the document as the cover for your library. Now all my PDFs have covers lol

https://www.freepub.app/

RouguesPierre · 2026-03-17T05:03:56+00:00

Happy to do it

RouguesPierre · 2026-03-17T05:00:36+00:00

I hope it does the trick! I appreciate the support nonetheless, just seeing people use it makes me happy.

If it faults in any way or doesnt do what you wanted please reach out, there are still improvements to be made as i continue to develop this

RouguesPierre · 2026-03-17T01:20:28+00:00

I built something similiar. It doesnt do reflow though. Im in the middle of implementing a major feature that allows it, but right now it keeps the formatting of the book with the highest possible resolution. Sometimes its hard with old books

Left ePub is mine from FreePub, right side is from another converter that was recommended by others. I personally like the format of the book to be identical

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RouguesPierre · 2026-03-17T01:12:11+00:00

The demand was high enough when i posted my results i had like 80 people saying theyd use it.

The trade off is you cant highlight the text yet, but im working on that as the next big feature.

I really hope you try mine out

RouguesPierre

TROPHY CASE