Guides · 4 min read
How to reduce a comic's file size without wrecking quality
Comics can be huge. Here's how to shrink a CBZ, PDF or manga file for faster transfers and more storage on your e-reader, while keeping the pages sharp.
A single high-resolution comic can run to hundreds of megabytes, and a full series can fill a device fast. The good news is that most of that size is wasted on data your e-reader can't even show. Here's how to trim it safely.
Match the resolution to your screen
The biggest saving comes from resizing pages to your device's actual resolution. A page scanned at 3000 pixels tall carries far more detail than a 1648-pixel Kindle screen can display — the extra pixels are thrown away at read time anyway. Converting to the device profile downsizes each page to exactly what the screen uses, often cutting the file by more than half with no visible change.
Drop the colour on grayscale readers
If you read on a standard grayscale e-ink device, colour data is pure overhead. Converting to grayscale removes it and shrinks the file further, with no loss on screen since the device shows grayscale anyway.
Choose a sensible quality
JPEG quality around 82–88 is visually indistinguishable from maximum on e-ink but produces dramatically smaller files. Pushing quality to 100 mostly adds bytes you can't see. TomoRead's device profiles already pick a sensible quality; you can nudge it in Advanced options if you want smaller or sharper.
If you're archiving a comic for the long term rather than reading it now, keep full resolution and PNG. Shrinking is for reading copies, not masters.
Why smaller files matter
Beyond storage, smaller files transfer faster — whether you're emailing a chapter to your Kindle or copying a series over USB. A volume that was 400 MB can often become 60–100 MB after fitting it to the screen, which is the difference between a quick sync and a long wait.