Convert PDF comics to EPUB
PDF comics read badly on e-readers: tiny margins, wrong aspect ratios, and reflow engines that mangle fixed art. Tanko renders each PDF page faithfully — including pages built from multiple images, transparency layers, and vector overlays — then packages a proper fixed-layout EPUB sized for your exact device.
Rendering happens in your browser, so nothing is uploaded and there's no page or size limit. Works for digital-first releases and DRM-free purchases alike.
How to convert a PDF comic to EPUB
- Make sure the PDF opens without a password. Password-protected and DRM-locked PDFs cannot be rendered in the browser, and the conversion stops with an error. Files you can open in any PDF viewer without entering a password are fine.
- Choose the device profile. The profile sets the rendering scale as well as the output size: each PDF page is rasterized at 1.5 times the panel height (capped at 4x the PDF's nominal size) and then downscaled, which keeps text and line art sharp after resizing.
- Set direction and spreads. Right to left for manga PDFs. Spread detection reads the page boxes of the whole document before rendering: landscape pages are split when they are a minority, kept when they are the majority.
- Drop the PDF and download. Pages are rendered in order with pdf.js in a Web Worker and packaged as a fixed-layout EPUB named after the PDF. Nothing inside the PDF is uploaded.
PDF comics: scanned vs. digital
A scanned PDF is usually one large JPEG per page wrapped in a PDF container. Rendering it reproduces that image at the target scale, and the grayscale profiles then apply the same levels correction and dithering they would to a CBZ scan, so yellowed pages come out with a white background.
Digital-first PDFs are different: a page may be assembled from several image tiles, soft masks, vector lettering, and overlays. Rendering flattens all of that into one bitmap exactly as a PDF viewer would display it, on a white background, so transparent regions come out white rather than black or checkered.
Either way the result is a picture of the page. Text becomes pixels, so it is not selectable or searchable on the e-reader, and the file size is set by the page count and panel resolution rather than by the size of the original PDF.
Margins, page boxes, and two-up PDFs
Tanko does not crop. A letter-size PDF with white margins around the art keeps those margins, scaled with the rest of the page, and they show up as a border on the e-reader. If the margins bother you, crop the PDF in a PDF editor before converting.
Spread handling uses the PDF page dimensions, not the rendered pixels. A PDF where every page is a landscape two-page layout counts as landscape-format and is kept whole in Auto mode, which is usually wrong for a comic; choose Always split to turn each landscape page into two portrait pages.
The rendering scale is derived from the page height, so unusually small page boxes (some digital PDFs declare pages only a few hundred points tall) are rendered at up to 4x their nominal size. That cap exists so a tiny page box cannot demand an enormous render; for normal page sizes the render is comfortably above the panel resolution.
Frequently asked questions
- Why render instead of extracting the images?
- Real-world comic PDFs often build one page from several images, transparency masks, and fragments. Extracting images gives you broken or duplicated pages; rendering reproduces exactly what the page looks like.
- Does this work for manga PDFs?
- Yes — set reading direction to right-to-left and the EPUB is built with proper manga page progression, including correct handling of double-page spreads.
- Does the text in a PDF stay selectable after conversion?
- No. Every page is rendered to an image, so text, links, and bookmarks in the PDF become part of the picture. For comics that is the point; for a text-heavy PDF, a reflowable conversion in another tool would serve you better.
- My PDF has two comic pages side by side on each page. What should I pick?
- Set spreads to Always split. Auto treats a document where most pages are landscape as a landscape-format book and keeps the pages whole, so the explicit setting is needed here. Right to left splits right half first, left to right splits left half first.
- Why is the EPUB much smaller than my PDF, or much larger?
- The EPUB stores one JPEG per page at the panel resolution, quality 85. A high-resolution scan PDF usually shrinks a lot; a compact vector PDF grows, because vector art that took a few kilobytes becomes a full-resolution bitmap.
- Do my files get uploaded anywhere?
- No. Conversion runs entirely in your browser — the file never leaves your device. That's also why there are no size limits or queues.
- Is this really free?
- Yes. Single-file conversion with every device profile and every option is free, with no sign-up and no watermarks.