EPUB Indexing Methods
Before CrossInk can display an EPUB chapter, it lays out the chapter into pages and saves that layout in the book’s cache. Indexing Method chooses whether CrossInk finishes that work before you start reading the chapter, or does it a little at a time as you read.
The default is Full Section. Most books work well with it. Choose Incremental for a book with unusually large chapters, or when waiting for an entire chapter to open is more disruptive than seeing a short indexing wait later.
| Method | What happens | Main benefit | Main tradeoff |
|---|---|---|---|
| Full Section | Builds and caches the whole chapter before it is shown. | Normal page turns within the chapter do not need more indexing. | A large uncached chapter can take a noticeable time to open. |
| Incremental | Builds enough pages to show your current position, then continues in small background steps while you read. | You can begin reading a large chapter sooner. | If you reach pages that have not been built yet, CrossInk may briefly show Indexing while it catches up. |
Full Section
Full Section finishes the complete chapter cache before CrossInk displays an uncached chapter. This is the simpler, more predictable experience for normal EPUBs: after the initial wait, the chapter’s page count and all of its pages are ready.
CrossInk also tries to build the next chapter while you are reading the penultimate page of the current one. When this succeeds, moving to the next chapter does not require a visible indexing wait. It is deliberately best-effort: on the X3/X4’s limited memory, CrossInk skips that background work when there is not enough free or contiguous memory, and indexes the next chapter when you enter it instead.
Use Full Section when:
- Most chapters open quickly and you want the smoothest page turns.
- You prefer any indexing wait to happen at the chapter boundary.
- You want a complete chapter cache and final page count as soon as it opens.
Consider Incremental when a particular chapter takes a long time to open, or when a very large chapter is more likely to stress the reader’s available memory.
Incremental
Incremental builds only as far as CrossInk needs to display the current page. It keeps a small number of pages ready ahead of your reading position and uses short background steps to extend that ready area. Think of it like loading the first screen of a long web page first, then preparing the rest while you read.
This avoids making you wait for every page in a very large chapter before you can start. CrossInk saves the pages it has already built, so leaving the book does not discard that readable progress. A giant chapter may therefore remain partially indexed until you read farther into it; it does not have to finish in one continuous session.
Use Incremental when:
- A book pauses for a long time at Indexing before its first page appears.
- The book has exceptionally large chapters, such as omnibus editions or poorly split EPUBs.
- Starting to read sooner matters more than avoiding an occasional wait later.
Expect a visible Indexing popup if you jump far ahead, follow a link to an unbuilt part of the chapter, or turn pages faster than the background work can stay ahead. That is normal: CrossInk is building just enough additional pages to make the requested position readable.
KOReader Sync uses the same content location rather than the other device’s page number. If a synced location is beyond this device’s saved incremental prefix, CrossInk indexes forward until that location is available. Switching between Incremental and Full Section does not change the saved reading location: Full Section resolves it as soon as the chapter is built, while Incremental only builds through the requested content.
Changing The Setting
To change the default for future EPUBs, open Settings → Reader → Indexing Method and choose Incremental or Full Section.
To change it only for the EPUB you are reading, open the reader menu, choose Reader Options, then choose Indexing Method. The per-book choice is saved with that book and overrides the global default without changing your other books.
Changing the method does not discard the chapter currently on screen. The new choice is used the next time CrossInk needs to index a chapter. It also does not alter the EPUB file itself, your reading progress, bookmarks, clippings, or reading statistics.
If A Book Is Still Slow Or Cannot Index
Indexing Method changes when CrossInk performs layout work; it does not simplify the publisher’s CSS, images, or tables. If a difficult EPUB is still slow or runs out of memory, try a lighter EPUB Render Mode or optimize the EPUB before copying it to the device.