PocketBook InkPad 4 · Troubleshooting
PDFs are slow or cramped on the PocketBook InkPad 4
A PDF turns pages slowly, the text is tiny with big white borders, or it will not remember your zoom. This is almost always settings, not the device.
Symptoms
- Turning a page in a PDF takes two or three seconds.
- The page has huge white margins and small text.
- Zoom and pan reset every time you turn the page.
- A two-column paper is unreadable at full-page zoom.
- Heavy ghosting builds up over a few PDF pages.
Before you start
- Note whether it is one PDF or every PDF — one bad file behaves differently from a settings problem.
- Know roughly the file size; a 200 MB scan is inherently slower than a 3 MB text PDF.
- None of these steps change the file itself.
Which fix do you need?
Most common cause
The stock PDF reader opens a document at full-page zoom with no crop, which wastes the screen on white margins and forces slow full-page redraws. Setting a crop, a locked zoom and a suitable view mode fixes the size and most of the speed. Genuinely heavy scanned files are always slower and are the case for KOReader.
Fixes
Fix 1 Crop the margins and lock a view
Most of the wasted space and re-zooming comes from opening the PDF full-page with no crop and no locked zoom.
- Open the PDF, tap the top centre, and choose "Crop". Use the automatic crop or drag the guides to trim the white border. This alone enlarges the text noticeably.
- Set a comfortable zoom, then choose a "Columns" or locked-zoom mode so the setting sticks and the buttons walk down the page, then to the next.
- For a two-column academic PDF, the "Columns" mode reads the left column top-to-bottom, then the right — set it once per document.
- Use the "Contrast" control to darken a faint scan.
Fix 2 Speed up page turns on all PDFs
Every PDF page is an image the device has to render and push to the e-ink panel. A few settings cut that work.
- In the PDF menu, turn off any "smooth" or high-quality rendering option while you are just reading; turn it back on only when you need fine detail.
- Set the page-refresh interval so the screen does a full flash every few pages rather than every page — fewer full flashes means faster turns, with a little more ghosting between them.
- Keep the device's storage from filling up; a nearly-full device is slower at everything.
- Restart the InkPad 4 if it has been on for days — a fresh start clears a slow-drift.
Fix 3 Use KOReader for heavy or scanned PDFs
KOReader's PDF engine is faster with large scans, remembers per-document crop and zoom, and reflows text PDFs more cleanly than the stock reader.
- Install KOReader from the KOReader section — it is one file in the "applications" folder, no jailbreak.
- Open the problem PDF in KOReader, set the crop and zoom once; it stores them with that document.
- For a born-digital text PDF that is still awkward, try KOReader's reflow, which handles paragraphs and hyphenation better.
- If even KOReader struggles, the file itself is the limit — re-export or re-scan it at a lower resolution, or split it into parts.
Undo / recovery
Everything here is a view setting or a second reading app; the PDF files are untouched. Crop, zoom and mode are saved per document, so a change to one PDF does not affect the others.
Related guides
Almost every PDF complaint on the InkPad 4 is fixed by cropping the margins and locking a zoom and view mode — after that the buttons just page through. Slow turns ease with lighter rendering and less frequent full refreshes. For big scanned books, KOReader is the right tool and installs in ten minutes.