A source EPUB that already has missing chapters or broken notes makes translation difficult to evaluate. Before uploading, establish what is in the file and save a clean original. You do not need to unpack every EPUB or learn its internal formats to make these practical checks.
This checklist stops at submission. The separate translated EPUB validation guide covers the downloaded result.
Open the source as a reader would
Open the EPUB in your normal reader and visit more than the first page. Read a paragraph, change the font size, and open a later chapter. If it does not open, try another compatible reader before assuming the translation service can repair it.
A file with an .epub extension may be damaged, incomplete, protected, or simply not what you expected. Renaming another file does not make it an EPUB. Obtain a usable authorized edition if the source cannot be read normally.
Watch for garbled characters and unusually rigid pages. A fixed-layout book may legitimately behave differently from a reflowable novel. Knowing that before translation prevents you from attributing every display difference to the language stage.
Compare the chapter list and resources
Use the table of contents to jump to several chapters, including the last one. Compare the list with the book's visible contents and any known part divisions. Open chapter endings too: an excerpt can have a convincing title and cover while stopping before the intended ending.
Inspect an illustration, a caption, a table, and a note if present. Follow a note reference and return to the main text. Check whether important wording is ordinary text or embedded in an image. Retaining an image later is not the same as translating lettering inside it.
For a collected web serial, check duplicated headers, missing continuation pages, and the ordering of chapters. Correct those source problems in an appropriate editing workflow before translation. Keep an unchanged copy so cleanup does not silently remove original content.
| Source check | Record before upload |
|---|---|
| Completeness | Expected chapters or parts and where the book ends |
| Navigation | A few known chapter destinations and note links |
| Resources | Illustrations, captions, tables, and any image-only text |
| Display | Existing font, character, or layout problems |
Prepare language and background notes
Decide the target language and whether you want only the translation or a bilingual edition. In PDF Craft, bilingual EPUB output places the translation after each original passage. It is useful for comparison but increases the text you move through.
Prepare a brief description of the subject and a few preferred names or terms. For example: “This is an introductory astronomy book. Keep personal names unchanged and use standard astronomical terminology.” A novel may need a different brief about dialogue and invented terms.
Use known facts. An incorrect summary can mislead interpretation, while an unrelated long prompt makes the important requests harder to identify. Instructions guide the translation; they do not guarantee every occurrence will follow the preference. Keep your notes for later review. See writing translation instructions for examples.
Preserve the original and a simple file record
Keep the source under a distinct filename outside the download folder used for results. Record its title, language, and edition or version when relevant. If you revise or replace the source later, this helps identify which file produced the translation.
For sensitive content, settle upload permissions before submitting. Do not assume a desktop viewer or a local source file means the translation itself runs offline. Use the privacy checklist when the document requires closer handling.
Review the actual task settings
Open the EPUB translator, upload the complete file, and confirm the target language, output mode, and instructions. The landing-page URL does not set those parameters for you. Check current file and processing limits rather than assuming any book will be accepted.
New users receive trial credits, and translation is charged by usage. Read Pricing for current rates. When ready, submit and keep enough source notes to check chapter navigation, recurring terminology, and important passages after download.
If your final destination is a Kobo, keep that import as a separate step; the Kobo reading guide explains it. The goal before upload is simpler: a complete source that opens, a clear language choice, and no uncertainty about which original you will compare against.