Guides
Kindle & PDF guides
Practical guides for sending PDFs to Kindle, fixing Send-to-Kindle failures, converting to KFX format, and choosing the right e-reader for reading-heavy workflows.
Updated May 17, 2026
Send to Kindle not working: 7 fixes and a backup that always works
Troubleshooting guide for all common Send-to-Kindle failures — approved sender list, file size limits, unsupported formats, delivery delays, and a KFX sideload fallback.
Read guide →Updated May 22, 2026
Send to Kindle E999 internal error: what it means and how to fix it
Error-code-organized troubleshooting for the E999 internal error — diagnostic fixes by root cause (oversize, malformed EPUB, DRM, transient failure), authentication failures, and silent non-delivery.
Read guide →Updated May 17, 2026
How to send PDFs (and EPUBs, Docs, MOBI) to Kindle: every method
All four methods for sending files to any Kindle device — Send-to-Kindle email, the mobile app, USB cable, and converting to KFX for sideloading.
Read guide →Updated May 17, 2026
Kindle Scribe vs. reMarkable vs. iPad vs. Paperwhite: which is best for reading PDFs?
Use-case-first comparison of four e-reading devices for PDF-heavy workflows — academic papers, annotations, general reading, and multi-column documents.
Read guide →Updated May 15, 2026
How to convert PDFs to KFX for Kindle Scribe
Covers Send-to-Kindle's specific failure modes (column collapse, footnote loss, flat headings), Calibre's documented limits, and where a web-based converter helps.
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