Banana Comic Converter

What this does

Banana Comic Converter turns comic and manga files (CBZ, ZIP or PDF) into pages that fill an e-ink screen, as XTCH (Xteink devices), EPUB or CBZ. It runs entirely in your browser; nothing is uploaded. Use it only with files you own or have the right to convert.

Quick start

1. Add your comics. Drop CBZ, ZIP or PDF files (or whole folders) on the box, or click it to browse. Optional: open Pages to reorder pages, hide ads or credits, or pick a cover.
2. Choose your reader. Pick your device from the list (or Custom to type its screen size) and say which way you read. Not sure about the direction? Press Not sure? Test it on your comic.
3. Choose what to make. For an Xteink X3 or X4, the Quick setup list does everything in one choice. Otherwise tick the file format (XTCH, XTC, EPUB, CBZ) and the screen orientation. Estimate file size shows what to expect.
4. Choose how pages are cut. Smart panels finds each panel and fits it to the screen. Simple halves or thirds just cuts each page into 2 or 3 overlapping parts. You can check the result in the panel editor before converting.
5. Tick I own these files in the bar at the bottom and press Convert. A progress bar shows the file, page and time left, and Cancel stops it between pages.

Everything under More options (output details, panel settings, image quality, metadata, saved presets) is optional; the defaults work well.

Finding your way around

• The rows under More options open and close, and each shows a one-line summary of its settings. Use Expand all / Collapse all beside the heading. Which rows are open is remembered in this browser.
• The small i next to a section title explains that section.
• Saved presets stores all settings under a name (not files, metadata or panel edits). Presets live in this browser only, but Export and Import move them between browsers and devices, and clearing site data removes them.
• Page order inside a file is sorted naturally. A page named "cover" goes first; credits, scanlation and thanks pages go last. Chapters come from file or folder names (such as "ch12"), or from the PDF's bookmarks, and are used for the EPUB table of contents and the XTCH chapter list.

Smart panels or Simple page split

• Smart panels (Panels section) detects each panel, orders them for your reading direction, packs small panels together, and enlarges long panels. Everything in the Panels section, the panel editor and the zoom rules belong to this mode.
• Simple page split skips all of that. Every page is cut into 2 (halves) or 3 (thirds) equal parts with an overlap you choose (Small 8%, Medium 15%, Large 25% of the page), in reading order. Optionally show the whole page first. Landscape screens get top-to-bottom bands so each part fills the screen width; portrait screens show pages whole (wide double-page spreads are cut left and right, right half first for manga). Mixed output and the panel editor are not available in this mode. Device, output, cover, image quality and metadata settings still apply.

Screen shapes

• Portrait and Landscape put every screen in that shape. Landscape and portrait can be made in the same run.
• Mixed makes one file where each panel goes on the shape that suits it: wide panels on landscape screens, tall panels on portrait screens. A panel uses a landscape screen when its width ÷ height is at least the ratio you set (default 1.15; 1.0 picks whichever shape fills the screen better, higher keeps more panels portrait). Neighbouring panels of the same shape can still share a screen, and the long-panel and dense-zoom rules apply to each shape. You turn the device when the orientation changes. EPUB readers may not rotate automatically, so check yours.
• Keep the cover shows the first page whole on a portrait page in landscape and mixed output (it is not cropped, packed or rotated). In EPUB and CBZ it also becomes the cover image.

File types

• XTCH is a 4-level gray container for Xteink devices. Landscape pages are stored sideways in the portrait file, so you turn the device to read them. Options: landscape page rotation (switch it if pages look upside-down), dither style (Floyd-Steinberg smooth, Atkinson crisper, Ordered pattern, or None), and an experimental cover thumbnail that has not been tested on devices. The format follows a community description and is untested on some devices.
• EPUB is fixed-layout with a chapter table of contents and full metadata. CBZ is plain image pages plus a ComicInfo.xml with metadata.
• Output files are named name-portrait, name-landscape or name-mixed plus the file type.

Zoom and splitting (Smart mode)

These are the only two settings that show a screen whole first and then enlarged pieces of it. Each adds extra pages.

• Long panels: a long single panel is shown whole, then as two enlarged halves (landscape: tall panels top then bottom; portrait: wide panels, right then left for manga). It only splits when long side ÷ short side reaches the threshold (default 1.3; raise it to split fewer). Panels that are grouped, or already fit the screen well, are not split.
• Dense page zoom (Off by default): crowded screens are shown whole, then as zoomed tiles in reading order (usually 3 bands in landscape, a 2×2 grid in portrait). Auto only acts when long border lines run through the picture; Always applies to every large single screen. It takes priority over the two-halves split.
• Overlap (Small, Medium, Large) is used by both when there is no blank gap to cut at, so a speech bubble on the cut shows whole in at least one part.

Packing

Max panels per screen (3, 2 or 1) caps how many small panels share one screen; choose 1 to never combine. Minimum scale kept (0.5–1, default 0.75) decides how much smaller than their solo size panels may get when grouped: lower packs more per screen, higher keeps them larger.

Gap colour between panels

Auto spots pages whose outer margin is dark and detects panels with the black gaps treated as gutters (it only accepts that when it finds at least two panels). White gaps only turns that off. Black gaps on every page forces it for the whole book.

What the panel editor is for

The converter first guesses where the panels are. The editor lets you see those guesses, correct them, and see what each box will become on your screen. Your edits are used when you press Convert and are remembered until you reload the page; the count of edited pages shows next to the buttons. It is available in Smart panels mode only.

Opening it

• Preview and fix panels opens the first page so you can go through everything.
• Review flagged pages only opens it in flagged mode and jumps to the first page that needs a look.
• With several files, pick the file from the list at the top of the editor. The Help button opens this guide.

Reading the page view

• Yellow boxes are the detected panels, numbered in reading order. The selected box is darker and has square handles.
• Coloured dashed overlays (zoom 1a, zoom 1b) are the enlarged parts a box will also be shown as, after being shown whole. A grey label such as with 3+4 means small boxes share one screen. In the Mixed preview each box also gets a landscape or portrait tag.
• The line under the page shows the selected box's size and shape, and how much of a landscape or portrait screen it fills.
• Screen preview (side panel) turns the overlays on or off and switches the preview between Landscape, Portrait and Mixed. It uses your current settings (long-panel split, dense zoom, max panels per screen, reading direction, mixed ratio, cover rule). Grouping of small boxes is estimated within the page only.

Fixing boxes

• Select a box by clicking it (the smallest box under the pointer wins). Move it by dragging. Resize with the corner and edge handles.
• Draw box: turn it on, then drag on the page. The new box goes after the selected one in the order.
• Merge next (M) joins the selected box with the one after it. Split by line (C) lets you drag a line across a box to cut it in two; a mostly horizontal drag makes a horizontal cut, a mostly vertical drag a vertical one. Review all pages (Panels section) shows every page with its boxes in a grid so you can open only the bad ones.
• Delete box removes it. Delete every box on a page to skip that page (ads, credits).
• Earlier / Later move the selected box in the reading order. Sort by reading order re-sorts every box automatically; it handles a tall panel beside stacked ones.
• Whole page replaces all boxes with one box covering the page (good for splash pages).
• Re-detect throws away your edits on this page. Black gutters re-detects this page treating black gaps as the gutters.
• Undo steps back through your changes on this page (history clears when you change page).

Zoom for one box

Select a box, then under Selected box choose how it is shown:

• Auto (default) follows your long-panel split and dense page zoom settings.
• Off shows the box as it is, with no zoom, even if a zoom setting would normally cut it.
• Halves or Thirds show the box whole, then enlarged overlapping parts in reading order. The cut that enlarges the parts most is used (top-to-bottom bands or left-to-right columns), snapped to blank gaps where there are any, with the overlap from your zoom settings. A box with halves or thirds is never packed onto a screen with other boxes.

A small purple tag on the box shows its zoom choice, and the screen preview shows the parts. Zoom choices are kept when you move or resize the box.

Box shape lock

Choose Landscape screen shape or Portrait screen shape to draw and resize boxes with exactly your device's proportions, so they fill the screen with no side bars. Keep the selected box's shape resizes without changing proportions. While locked only the corner handles are used.

Pages to check

Instead of going through every page, let the editor point out pages worth a look. A background scan starts when you open a file (you can stop it and resume it, or rescan).

• Filter by problem flags (default). Under Flag pages with, Several panels in one box (shown as Grouped?: near-black borders run along most of a box) and A very big box next to other boxes (Big) are on. Overlapping boxes (Overlap) is also on. Optional, off by default: Very tall or very wide boxes and Many boxes (Busy). Sensitivity (Low, Normal, High) controls how many pages get flagged. A single full-page box is not called Big, so splash pages are left alone.
• Filter by number of panels: show only pages with a panel count in a range (for example 1–2), or tap a count button to see exactly those pages.
• Step through flagged pages only makes Prev / Next jump between matching pages. The chips list them; ones you have already looked at are dimmed. Turn it off to go through every page.

Keyboard

• ← / → go to the previous / next page (PageUp / PageDown and P / N work too). ↑ / ↓ or 1–9 pick a box.
• H halves, T thirds, O no zoom, A auto for the selected box. D draw, Delete remove, [ / ] earlier / later, W whole page, R re-detect, S sort, F flagged pages only, Ctrl+Z undo.
• Shift + arrows nudge the selected box; add Ctrl for bigger steps.

Good to know

• The editor shows each page as it is read, before cropping or scaling.
• Edits are tied to the file name and size and are lost if you reload the page. Changing the reading direction later does not re-order pages you already edited (use Sort by reading order).
• The first page is kept whole in landscape and mixed output when keep the cover is on, so box edits there only affect portrait output.

All settings, section by section

Files

CBZ, ZIP, PDF; drag and drop or browse; batches get their own outputs; unreadable pages are skipped and counted in the summary.

Device and reading

Reading direction, screen preset (X4, X3, Kindle, Kobo and others) or custom portrait width × height.

Output

Screen shapes, file types, mixed ratio, keep the cover, and the XTCH options (rotation, dither, cover thumbnail).

Panels

Conversion mode (Smart panels or Simple page split); in Smart mode the panel editor buttons, gap colour, long-panel split and threshold, dense page zoom, overlap, max panels per screen and minimum scale kept; in Simple mode parts per page, overlap and show-whole-page-first.

Image quality

• Sharpen (on, strength 0.5) helps enlarged panels look crisp. E-ink contrast (on) gives deeper blacks and whiter paper. Darken midtones (Medium) keeps shading and helps if grays look faded.
• Reduce screentone moiré (Off, Light, Strong) softens fine dot patterns before a big shrink, which causes the wavy look; Strong can blur small text a little. Auto-levels (off) stretches each screen to black and white for faded or yellowed scans.
• JPEG quality (50–95, default 80): higher is sharper and larger.

Metadata

Title, author, series, volume, publisher, year, language and description, pre-filled from the file (CBZ ComicInfo.xml or PDF properties). Blank fields keep what each file has. With several files each gets its own Title and Volume row; the rest applies to all. An option adds "- portrait", "- landscape" or "- mixed" to the title. EPUB stores everything, CBZ stores it in ComicInfo.xml (with a right-to-left manga flag), XTCH stores only title, author, publisher and language.

Saved presets

Name, save, load and delete full sets of settings. Older presets still load.

Bottom bar

Consent checkbox, a summary of how many outputs will be made, and Convert.

Tips and fixes

• Just want it fast? Use Simple page split (halves or thirds). No editing needed.
• Too many pages? Turn off the long-panel split, keep Dense page zoom Off, or raise the split threshold.
• Pages show whole and then zoomed even with dense zoom off? That is the long-panel split. Untick it in Panels.
• Text too small on a crowded page? Fix its boxes in the editor, or set Dense page zoom to Auto.
• Panels in the wrong order? Open the page in the editor and press Sort by reading order, or use Earlier / Later.
• Page with black gaps between panels? Leave Gap colour on Auto, or press Black gutters in the editor for that page.
• A box holds several panels, or the page was missed? Use Review flagged pages only, then redraw or resize the boxes. Raise sensitivity for more flags, lower it for fewer.
• Speech bubble cut in half? Use a larger overlap.
• Device runs out of memory or will not open a big XTCH? Set Split into parts under Output (about 150 to 200 screens per file is a good start). Each part is a separate, smaller file that starts at a chapter where possible. Fewer screens also helps: one orientation only, long-panel split and dense zoom off, max panels per screen 3.
• Want black and white only, or smaller files? Tick XTC (black & white) under File types. It stores 1 bit per pixel, so each screen is about half the size of XTCH. Use the cutoff number to make pages lighter or darker, and the dither style to choose between smooth and crisp.
• Split files in folders? With Split into parts on, set ZIP download layout to put each book (and each set of parts) in its own folder inside the ZIP. Parts are named part1, part2 ... (part01 ... when there are ten or more).
• Landscape XTCH looks upside-down? Switch the page rotation.
• Grays look faded? Raise Darken midtones, or try Auto-levels for faded scans. Screentone looks wavy? Turn on moiré reduction.
• Slow on large PDFs? Conversion runs in the page itself and pauses between pages so Cancel stays responsive; very large PDFs can still make the tab feel slow.
• Presets or edits gone? Presets are stored in this browser and removed when site data is cleared; panel edits last until the page is reloaded.

Disclaimer: known limits and what to expect

This is a hobby tool, not a finished product. It uses ordinary image analysis, with no AI, so it follows rules rather than understanding the page. It works best on pages with clear white or black gaps between panels.

Panel detection

• Many pages come out right, but some need a fix in the editor. Flags are hints, not a guarantee: some flagged pages are fine and some problem pages are not flagged.
• Panels with no borders, artwork that bleeds into the next panel, or panels sitting on top of each other can get a box that is too big, too small or overlapping. Inset panels over a full-page drawing are the usual case.
• Several panels can be merged into one box, or one panel split in two, especially on busy or very dark pages.
• Full-bleed layouts with slanted or overlapping panels often cannot be separated, because the gaps between panels are not straight and clear. On such books many pages will stay as one whole-page box. The page is still shown whole in the right order. Dense page zoom (Auto) can enlarge it in parts, but it can multiply the screen count a lot.
• Reading order is a best guess and unusual layouts can come out wrong. Use Sort order and Earlier / Later in the editor.
• Splash pages, double-page spreads and big sound effects may be treated as one big panel or cut in odd places.
• Speech bubbles can be cut when a long panel or a zoom is split. A larger overlap helps.
• Scans with gray backgrounds, noise or compression artifacts can make gaps harder to find.

Output

• XTCH and XTC follow community descriptions of the formats and have not been tested on every Xteink device or firmware. Try a short file first.
• Large XTCH files can run a device out of memory, because every screen is stored uncompressed. If that happens, use Split into parts under Output, use one orientation, or turn off zoom options that add screens.
• Mixed-orientation EPUB asks the reader to rotate per page, but not every reader does. If yours doesn't, use portrait or landscape output instead.
• Landscape XTCH pages are stored sideways, so turn the device to read them.

Size, speed and storage

• Everything is converted in your browser's memory, so large books are slow and use a lot of RAM, and output files can be large. Phones and low-memory devices may stall on very large files, so convert in chunks or one output at a time.
• Panel edits are lost if you reload or close the page. Presets are kept only in this browser, on this device.
• Tested mainly in Chromium (Chrome, Edge). Other browsers and phones have had little testing.
• Scanned PDFs are converted as page images. There is no text extraction or OCR.

Use only files you own or may convert for personal use.

If this tool saves you time, the Buy me a coffee button at the top is always appreciated.