Plan targeted repairs to a converted EPUB with Sigil
A small EPUB defect may suit a targeted Sigil repair. Make a precise repair list, keep a backup and compare the effort with a fresh conversion for widespread layout problems.
On this page
- Back up and repair one passage in Sigil
- Choose targeted editing or a new conversion
- Repair the passage you can identify in a real book
- Keep a real chapter heading before its opening
- Editing an EPUB differs from converting a PDF
- Build a repair list before opening the editor
- Use a real sample to decide whether to start again
Back up and repair one passage in Sigil
- Save an untouched copy before opening the editor.
- Find the exact broken passage in the source PDF.
- Make one local repair at a time.
- Save separately and reopen in the reader.
Choose targeted editing or a new conversion
Sigil editing is most useful for a small, understood defect in a book you can already read. If the problem affects every column transition, editing each paragraph can become a larger task than creating a new reading copy. Estimate the number of affected passages before committing to manual repair.
Use the editor’s current guide to locate the chapter and its markup. A heading repair changes the position or structure of the heading element; it is more than making its text look bold. Work on one section, save a new file and inspect the chapter navigation afterwards. If you are unfamiliar with markup, avoid a global replacement across the book. Preserve an untouched copy so you can recover from a repair that removes a picture reference or joins unrelated paragraphs. The source PDF remains the reference for intended content.
Repair the passage you can identify in a real book
Use Chapter I, Down the Rabbit-Hole, in Alice’s Adventures in Wonderland as a recognisable reading passage. For an actual defect in your own converted copy, record the sentence before and after the problem, then find that chapter in Sigil. Correct the smallest affected span using the source edition as your reference. Save a separate copy and read both surrounding paragraphs again. Do not rewrite Carroll’s words to make a broken extraction seem plausible. The linked book supplies a real passage to locate; we have not claimed or demonstrated a defect in its EPUB.
Open the published source.
Keep a real chapter heading before its opening
Use Chapter I, Down the Rabbit-Hole, from the source edition of Alice. If your converted copy moves that heading after its opening paragraph, compare the original before making a local correction. Reopen the saved copy, read the opening paragraph and follow the contents entry. This describes a defect to check in your own file, not a defect found in the linked published EPUB.
Editing an EPUB differs from converting a PDF
Sigil is an EPUB editor, not a general PDF converter. Complex repairs may require knowledge of the book markup. A clean sample conversion can be quicker than repairing widespread order errors by hand.
Build a repair list before opening the editor
Group defects by scope: one typo, one misplaced heading, a missing figure reference or a widespread reading-order problem. Local defects can often be repaired with a clear source reference. A widespread problem needs a realistic estimate of manual work before you start changing chapter after chapter.
Give every repair a source location and an expected result. For example, “keep Down the Rabbit-Hole before Alice’s opening paragraph” is actionable. “Make chapter better” is not. Keep any uncertain intended order marked as uncertain rather than editing to your preferred interpretation.
After saving, repeat the specific reading task. Follow the corrected contents entry, inspect the figure or read the repaired transition. Do not rely solely on the editor’s appearance. A repair can be visually plausible while breaking a link or dropping a caption. Keep the original EPUB until you have inspected the changed copy, and avoid global replacements unless the pattern is understood throughout the book.
Use a real sample to decide whether to start again
Our NASA sample retained the inspected numbered functions and hardware labels without editor changes. Open it to judge the kind of new reading copy EPUBTurn produces. If your current EPUB has only one misplaced heading, fixing that chapter in Sigil can still be faster than starting again. The sample’s generic Front matter title and partial page coverage also show why a fresh conversion needs checking rather than replacing your repair list automatically.
Open the actual source PDF · Download the saved EPUBTurn sample.
For your own document, create an EPUBTurn sample from your PDF, then use the reading checks described here.