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Mofumi PDF

E-reader Optimizer

Beta

Reformat a PDF for Kindle, Kobo or reMarkable: crop margins, greyscale, higher contrast and the right page size.

100% Private — files never leave your device
Upload PDFDrop files here or click to chooseAccepted: PDF Files never leave your device

About this tool

A normal A4 PDF on a 6–7 inch e-ink screen means tiny text surrounded by wide white margins. E-reader Optimizer crops those margins automatically, scales the content to fill your device's screen and renders each page in greyscale at the device's own resolution.

E-ink displays show only shades of grey and have lower contrast than paper, so the tool also stretches the tonal range, increases contrast and darkens thin strokes. Pages come out at the exact aspect ratio of the screen, so the reader doesn't add its own borders. Wide pages can optionally be turned sideways to read in landscape.

The output pages are images, which makes them display fast and consistently on any e-reader. The tool is in beta: results depend on the layout — pages with a header or footer far from the text crop less.

Engines: pdfjs · canvas · pdf-lib

How to use

  1. 1

    Drop the PDF you want to read on your e-reader.

  2. 2

    Pick your device, and adjust contrast or margin cropping if you like.

  3. 3

    Click Optimize for e-reader and copy the file to your device.

Use cases

  • Papers and reports

    Read academic papers on a Kindle without zooming and panning on every page.

  • Scanned books

    Remove yellowed margins and boost faded text of old book scans.

  • Notes on reMarkable

    Fit lecture slides and handouts to the reMarkable screen for annotation.

Frequently asked questions

Can I still search the text?

No — pages are converted to images. Keep the original PDF if you need search.

My device isn't listed.

Pick one with a similar screen: most 6" readers are 1072×1448, most 7" readers 1264×1680.

Why are my pages not cropped?

Cropping keeps everything printed on the page, so page numbers or headers near the edge limit how much can be removed.

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