Convert to Custom Dimensions
Sometimes no device preset fits: an unusual tablet, a print project, a homebrew reader, or a screen the picker does not list. The Custom conversion profile takes an exact width and height in pixels and rebuilds every page for precisely that canvas, with the full range of processing options open.
↑ Upload and configure in our Studio
It is the same KCC pipeline the device presets run, with the training wheels off: you set the dimensions, and manga mode, spread handling, cropping, gamma and format stay fully adjustable. The live preview renders your pages at the exact size before you convert. Around 1,400 conversions a month run through this profile, so it is a first-class path, not a leftovers bucket.
- Files auto-delete after 24 hours
- No install, runs in any browser
- Free to use
- The genuine open-source KCC engine
How to convert with custom dimensions
Drop your file
CBZ, CBR, CB7, ZIP, RAR, 7Z, PDF and EPUB all work, up to 20 files at once and 1GB each.
Enter width and height
The Custom conversion profile is preselected on this page. Type the exact pixel dimensions of your target screen or canvas.
Tune the full settings range
Every processing option stays available: manga mode, spread splitting, margin cropping, contrast and gamma, output format. Nothing is gated by a device profile.
Preview and convert
The live preview renders pages at your dimensions before you commit. Download EPUB, KEPUB, MOBI or CBZ; files auto-delete after 24 hours.
Exact pixels beat approximations
A page built for the exact panel is rendered 1:1; a near-miss gets rescaled on the device, which softens linework and screentone. That is the whole reason the profile asks for numbers instead of offering a generic large/small choice.
Portrait is the usual orientation
Comic pages are portrait, so width is normally the smaller number. If your target reads landscape, swap the numbers, and consider the rotate-spreads option for double pages.
Frequently asked questions
How do I find my screen dimensions?
Check the device spec sheet for the display resolution in pixels, width x height. For a tablet or phone, search the model name plus "screen resolution". When in doubt, the physical pixel count of the panel is the number you want.
Why not just pick the nearest device preset?
If your device is in the picker, its preset IS the right choice: the profiles carry true resolutions plus per-device tuning. Custom dimensions exist for the screens the picker does not know, where an exact number beats a nearby guess.
Which output format should I use?
EPUB is the safe default for reading apps and most readers, KEPUB for a Kobo, MOBI for old Kindle workflows, and CBZ if you want the processed images themselves. All four are available with custom dimensions.
Is this free?
Yes. Custom conversion is part of the free tier like every profile, running the open-source KCC engine with a live preview and nothing to install.
Conversion runs on Kindle Comic Converter (KCC), the open-source engine, with the Custom conversion profile exposing its full settings range. Hosted here with a live preview so there is nothing to install.
Free, no install, live preview at your exact size