What Metadata Should Authors Add To Sigil Epub?

If you're prepping an EPUB in Sigil for stores, here's my usual checklist and workflow — I treat validation like a mini detective game, hunting down HTML oddities and metadata gremlins. First, I make sure Sigil's internal structure looks sane: proper mimetype at the top of the ZIP (Sigil handles that for you usually), a valid container.xml, and a clean OPF/nav or NCX. I use Code View to quickly scan the manifest and spine to confirm every file listed actually exists and that media-type attributes are correct. I tidy up stray inline styles, remove leftover Word markup, and make sure images are RGB (stores hate CMYK) and sensibly sized — especially cover images, since Kindle and Apple do their own conversions and will sometimes complain about unusual dimensions. After that initial sweep, I run Sigil's validator plugin (FlightCrew or the EPUBCheck bridge depending on my Sigil version). FlightCrew is great for quick checks inside the editor — it flags missing files, invalid GUIDs, and basic structural issues. But I always follow up with the official epubcheck (the command-line tool) because store submission systems generally expect EPUB to be fully compliant with the spec. epubcheck will spit out warnings and errors; errors are must-fix, warnings I triage (some are stylistic, some indicate potential reading-order or accessibility problems). Key things epubcheck catches that stores care about: duplicate IDs, broken links, missing referenced files, and nav vs NCX inconsistencies (EPUB2 vs EPUB3 issues). I keep an eye on the package metadata too — language, unique identifier (ISBN or UUID), and title/creator tags so metadata ingestion on a store side goes smoothly. Validation isn't just technical conformance, though — I test the EPUB in multiple readers because each store's engine will render things differently. I open the file in Thorium Reader or Adobe Digital Editions for a baseline, in Readium or Firefox EPUB extensions for web-ish rendering, and then I toss it into 'Kindle Previewer' (Amazon converts EPUBs to KPF under the hood, and Kindle Previewer shows how the conversion behaves). For Apple and Kobo I use their preview tools or just load the file in Apple Books and Kobo Desktop. If something looks off — weird font fallback, CSS not applied in the right order, or TOC items missing — I trace it back to the HTML/CSS in Sigil and repair. I also test accessibility basics: alt text on images, logical heading order, and readable language tags. Finally, after fixes and another epubcheck pass, I upload to the target store's submission portal (KDP, Apple Books, Kobo Writing Life, etc.) and preview there. Some platforms will flag proprietary issues only visible when they run conversions, so this last check is crucial. I try to keep a clean version history too — export dated EPUBs (EPUB v2 vs v3 can behave differently) so if a store rejects something I can quickly roll back. It's a bit of an art and a little like polishing a story before release, but once everything validates and previews correctly it feels really satisfying — give it a try and you might enjoy the tiny victory of a perfect validation log.

I’ve been digging around for this a lot lately, and the clearest, safest places to get 'Sigil' or EPUBs that work with it are the official sources first. For the editor itself, I always grab installers from the official site sigil-ebook.com or from the project's GitHub releases page (github.com/Sigil-Ebook/Sigil/releases). Those two are the freshest builds and usually have checksums and release notes. On Windows you can also find installers via Chocolatey, and on macOS people often pull it from Homebrew Cask. Linux users typically get it from distro repos, Snap, or Flatpak if a packaged build is available. If what you actually meant was where to download EPUB books to edit or read in 'Sigil', stick with legitimate public-domain or indie storefronts: Project Gutenberg, Standard Ebooks, Internet Archive, ManyBooks, and Smashwords are great legal sources. For commercial purchases, Kobo and Apple Books often sell EPUBs (though some have DRM). I tend to avoid shady sites — you can wreck a neat editing workflow with a DRM-locked file. Finally, double-check file integrity and metadata after download. Pair 'Sigil' with 'Calibre' for library management and conversions when needed, and enjoy tweaking those EPUBs — it's oddly satisfying.

Totally doable — I've turned a mess of EPUBs from Sigil into nice Kindle files more times than I can count, and the process is simpler than you might fear. First, finish and validate the EPUB inside Sigil: check metadata, set a cover, and use Sigil's validation tool or run EPUBCheck to catch broken XML or missing nav. If the EPUB is clean, my go-to is Calibre. Drop the EPUB into Calibre, select it, hit 'Convert books' and pick 'MOBI' as the output. Tweak the "Page setup" (choose the target device family) and "Structure detection" if chapter headings haven't been recognized. If you prefer command line, Calibre's ebook-convert works great: ebook-convert "book.epub" "book.mobi". A few practical gotchas: remove DRM first (you can't convert DRM-protected files legally); optimize large images; test the generated MOBI in Kindle Previewer or on an actual device. Also note Amazon's ecosystem now favors AZW3 or KFX for richer formatting, so if you care about fonts and layout, try exporting to AZW3 instead of MOBI.

Oh man, accessibility in ePubs is one of those topics I genuinely geek out about — and Sigil is such a handy playground for fixing things up. If you’re trying to make an EPUB more accessible, it’s not just about one magic plugin; it’s a combination of tidy markup, metadata, and a few validation/checking tools that point out what’s missing. In practice I rely on Sigil’s built-in features plus a few companion tools or plugins: the EPUBCheck validator (either the plugin wrapper or the external app), the DAISY Consortium’s ACE accessibility checker (run outside Sigil but essential), HTML Tidy or a Tidy-like plugin to clean malformed tags, and the built-in Find & Replace (or a regex helper plugin) to batch-fix missing alt attributes or broken headings. Those are the workhorses that catch structural and syntax issues early, which makes the rest of the accessibility work way easier. One thing that’s helped me tons is using the TOC generator (Sigil’s built-in Table of Contents tool or a TOC-focused plugin if you prefer more control) to create a proper nav.xhtml — a good nav is huge for screen-reader navigation. I also lean on a metadata or insert-metadata plugin to ensure the package contains language declarations and accessibility metadata fields (like dc:language and meta elements for accessibility). HTML Tidy/plugins will normalize stray tags and fix unclosed elements, which can break screen readers; after running tidy I frequently use the Find & Replace or regex plugin to add missing alt="" attributes to images (or to insert descriptive text where needed). For images that need longer descriptions, I’ll add figure/figcaption or aria-describedby targets — small edits but they make a big difference when a book is consumed with a screen reader. Beyond those, some very practical plugin-focused and workflow tips: run EPUBCheck first to spot manifest and spine mismatches, then run ACE to get accessibility-specific problem lists (e.g., missing language tags, inaccessible tables). Use a code-view helper plugin or Sigil’s Code View to ensure headings are semantic (h1, h2, etc.) rather than visual-styled bold text. Tables should have proper headers and summaries — a plugin or a small XSLT/script can help convert visual tables into semantic ones if you’re fixing a messy conversion. For keyboard testing and real-world verification, nothing beats opening the EPUB in a screen reader like NVDA (Windows) or VoiceOver (macOS) and walking through navigation, links, and images; that manual pass often reveals things the automated checkers miss. I’ve patched up novels and fan projects this way and each time it feels rewarding to see an EPUB go from “kinda usable” to actually pleasant for someone relying on assistive tech. If you want a practical next step: run EPUBCheck, run ACE, tidy your HTML, check headings and nav.xhtml, and use Find & Replace to fix alt text and language tags. It’s a little bit of elbow grease, but once you get the workflow down, accessibility fixes become fast and satisfying — and it always feels great knowing more readers can actually enjoy the book.

This one's a practical rabbit hole I love diving into — most major ebook stores and distributors will happily accept EPUB files you create with Sigil, but the exact rules and preferred flavors differ. The big direct retailers that let you upload EPUBs include Amazon KDP (they accept reflowable EPUB and will convert it to Kindle formats), Apple Books (the Partner Center wants EPUBs and actually prefers EPUB3 for richer layouts), Kobo Writing Life (EPUB is the standard), Barnes & Noble Press (EPUB uploads for Nook), and Google Play Books Partner Center (EPUB or PDF). Those are the storefronts most readers actually buy from, and each one has small quirks — Amazon runs its own conversion pipeline and sometimes asks for a KPF if you use Kindle Create, while Apple and Kobo are much happier with a properly validated EPUB 3 for interactive or complex layouts. If you want to get wide distribution without uploading separately to every store, aggregators and distributors are your best friends. Draft2Digital and Smashwords will accept EPUBs and distribute to many retailers and libraries, IngramSpark accepts EPUB for eBook distribution and is great if you want print on demand at scale, PublishDrive and StreetLib are other aggregator options that take EPUBs and push to various marketplaces, and BookBaby and Lulu are useful if you want a more hands-on conversion and distribution package. I’ve used Draft2Digital a few times because their dashboard makes sales reporting painless, and they handle minor conversions if something in the EPUB trips a retailer up. A couple of hands-on tips from doing this myself with Sigil: always run your EPUB through a validator like epubcheck — Sigil has plugins such as FlightCrew that make validation easier, but I like running epubcheck standalone too. Make sure your metadata is clean in the OPF (author, identifiers, language), include a proper nav file or NCX for older EPUB2 compatibility, and embed a cover image that meets the store’s pixel guidelines. Be mindful of EPUB2 vs EPUB3: EPUB3 supports better audio/video, fixed layouts and more modern CSS, but some older stores or tools still expect EPUB2 conventions. For image-heavy work like comics or illustrated novels, check whether the storefront prefers fixed-layout EPUB or a different format entirely — ComiXology and some comic retailers want CBZ/CBR, not EPUB. Always test the file in Kindle Previewer, Apple Books on a Mac, and a Kobo app if possible, because visual quirks show up differently across engines. If you’ve got a specific retailer in mind, I can walk you through the small gotchas for that one — file naming, required metadata, DRM options, or what to do if the validator throws mysterious errors. I actually enjoy tweaking CSS and metadata in Sigil until everything looks right on every device, so if you want help ironing out a particular EPUB, say the word and we’ll dig into it together.

Love this — designing covers for Sigil EPUBs is such a satisfying little craft, and I always geek out over the tiny details that make a book feel professional on any reader. First off, think pixels not inches: aim for a portrait aspect ratio around 1.6:1 (height:width). A practical baseline I use is about 1600 px tall by 1000 px wide as a minimum; if you want to future-proof for high-density screens, 2400 x 1500 or even 3200 x 2000 is fine as long as you manage file size. Use sRGB color profile, export photographic covers as high-quality JPEG and illustrations or images needing transparency as PNG. Keep the file optimized — try to keep the cover image under about 1 MB for distribution friendliness, using 70–85% JPEG quality and tools to strip unnecessary metadata. Also design with the thumbnail in mind: most people will first see a 150–300 px tall thumbnail, so prioritize bold composition, clear focal point, and large, readable type for title/author text. On the technical side, Sigil makes it pretty straightforward once you know the steps. Add your image to the book (drag it into the Book Browser or use File -> Add -> Existing Files), and then include a simple XHTML cover page that displays it. I like to create a file called 'cover.xhtml' with a single tag referencing the image in an images folder and CSS that uses max-width:100%; height:auto; display:block; margin:auto; to keep it responsive. In the package document (content.opf) you should ensure the cover image is listed in the manifest and properly marked: for EPUB 3 give the image manifest item the property 'cover-image' (for example, ). For EPUB 2 compatibility also include a metadata meta tag like . Don’t forget to put the cover XHTML as the first spine item so readers that show the first spine file as the initial page display your cover. Sigil’s Metadata Editor can help you check and add metadata, and the Book Browser makes it easy to see your files — but you can always hand-edit content.opf in Code View if you need to tweak manifest ids or spine order. Design-wise, keep text within safe margins (no type within 8–12% of the edge), use high-contrast colors and fewer than three typefaces, and avoid tiny decorative fonts for the title since they get lost at thumbnail size. If your cover is busy, add a subtle vignette or color overlay behind title text to increase legibility. Test the final EPUB in multiple readers (Calibre ebook viewer, Apple Books, Kobo, and a mobile reader) because each will render cover display slightly differently. Finally, remember that EPUB covers don’t need to include a back cover or spine the way print covers do — focus on a single, striking front image that tells the reader what kind of story or content they’re about. If you want, I can walk through a step-by-step Sigil workflow with screenshots next — would you like a compact checklist or a detailed walkthrough?

If you’re hunting for the official ePub of 'Sigil', the places I reach for first are the big, reputable ebook stores and the publisher’s own shop. I usually start at Apple Books, Google Play Books, Kobo, and Barnes & Noble’s NOOK store because they commonly sell properly licensed ePub files (or DRM-wrapped equivalents) and handle regional releases cleanly. Then I check the publisher’s website—many publishers (especially the likes of Tor, Penguin Random House, HarperCollins, or indie presses) sell direct ePub downloads or point to authorized retailers. Buying direct from the publisher sometimes gets you a DRM-free file or extras like author notes, which I love collecting. If you want DRM-free ePubs, I pay attention to shops like Smashwords, eBooks.com, or Humble Bundle when the title appears there. Always verify the ISBN and the publisher listing, and avoid sketchy download sites. Also don’t forget to check library platforms like OverDrive/Libby if you’d prefer borrowing first—sometimes that confirms edition details. Happy hunting; I usually bookmark the publisher’s page so I can snag special editions without worrying about fakes.

Alright, here's the way I usually tackle a corrupted EPUB that came out of Sigil — I get a little like a detective, opening it up and letting tools tell me what's wrong. First, I make a copy and change the .epub suffix to .zip so I can unzip it with 7-Zip or the system zip tool. If the container itself is corrupted, running zip repair tools (zip -FF broken.epub -O recovered.zip on Unix, or using 7-Zip’s Test feature and GUI repair tools like DiskInternals ZIP Repair) often recovers the archive so you can extract the internal files. Once I can see the EPUB internals, I run 'epubcheck' to get a list of validation errors — it’s the canonical validator and tells you which .opf, .xhtml, or manifest lines are unhappy. From there I either open the broken XHTML or OPF in a code editor and tidy it with xmllint --recover or HTML Tidy, or I import the whole folder into Sigil via 'Open From Folder' to let Sigil rebuild the spine and manifest. Calibre is another lifesaver: converting the file to another format and back to EPUB (or using Calibre’s 'Polish' feature) can regenerate a clean package. If I want to script fixes, Python’s ebooklib or Node epub tools are great for automating repairs. Finally, I validate again with epubcheck and test in Thorium or a phone reader — usually that iterative loop fixes things.