Ebook Formats: A Quick Guide For Self Publishers

Gary Smailes
Gary Smailes | 4 February 2026
Ebook Formats: A Quick Guide for Self-Publishers

The Main Ebook Formats (What They Are and When to Use Them)

Ebook formats sound like a problem for people who own three monitors and say things like "container file." You do not need to become one of them.

You need one clean rule: match the format to how readers will use the book. Reading on a phone at 11 p.m. is a different experience from filling out a workbook at a desk. The file should serve the experience, not your software.

Let's sort the big four.

EPUB: the default choice for most ebooks

If you write novels or narrative nonfiction, EPUB is your home base.

EPUB is reflowable, which means the text adapts to the reader's device and preferences. Bigger font, different font, wider margins, dark mode, small phone screen, huge tablet. The book flexes.

That flexibility is why EPUB works so well for text-driven books. Chapters, paragraphs, italics, scene breaks, a linked table of contents, footnotes. All of that travels nicely in EPUB when the file is built with clean styles.

Where EPUB shines:

Where EPUB starts to complain:

A quick reality check: readers expect to change font size in an ebook. If your reading experience breaks when someone bumps the font up two notches, you are fighting the medium.

Kindle formats (KPF/KFX/AZW): Amazon's house language

Kindle files are what Amazon sells to Kindle devices and Kindle apps. You will see names like AZW and KFX, and you might hear KPF if you work with Kindle Create. Here's the part you need to remember.

You do not have to generate these files yourself in most cases.

Amazon accepts an EPUB upload through KDP and converts it into a Kindle format for customers. Amazon's conversion has improved a lot. It still makes odd choices when your formatting is messy, which is why a clean EPUB matters.

So when should you care about Kindle-specific formats?

If your book is a standard novel, your workflow can be simple: produce a solid EPUB, upload to KDP, preview it, fix what breaks.

One warning, friendly but firm. Do not assume "looks fine in Word" means "will look fine on Kindle." Kindle conversion is less forgiving than your word processor, and readers are less forgiving than Kindle conversion.

PDF: a printed page trapped in a screen

PDF is a fixed-layout format. Every page is a snapshot. What you see is what you get, and what you get is what everyone gets.

That sounds comforting until you read a PDF on a phone. You pinch, zoom, scroll sideways, lose your place, repeat. If your book is meant to be read like a novel, PDF is the wrong tool.

PDF is great when the page design is part of the content. Think "the layout teaches."

Use PDF for:

Avoid PDF for:

A simple test: would a reader benefit from printing this? If yes, offer a PDF. If no, skip the PDF and build a proper ebook.

Also, do not confuse "PDF is easy to export" with "PDF is reader-friendly." Ease for the author is not the goal.

Fixed-layout EPUB: when design must stay put

Fixed-layout EPUB tries to keep the visual layout locked in place, while still being an EPUB. This is useful for books where the relationship between text and image carries meaning.

Common fits:

The trade-off is predictable. Fixed-layout EPUB is harder to test and distribution is less smooth. Different retailers and apps support fixed layout with varying levels of enthusiasm. A file that looks polished in one reader might look off in another.

If you go this route, budget time for testing across devices and stores. Also consider whether you need two editions, one fixed-layout for tablets and one reflowable for general ebook readers. Readers do not complain when you give them options. They complain when text is tiny and stuck.

Actionable advice you can use today

If you want the short plan most self-publishers should follow, here it is.

  1. Make EPUB your primary ebook file.
    Publish it wide to Apple Books, Kobo, Google Play Books, and aggregators.
  2. Upload that EPUB to Amazon KDP and let Amazon convert it to Kindle format.
    Then preview, because conversion errors are sneaky.
  3. Use PDF only when the page design is the experience.
    Workbooks, printables, textbooks, layout-driven nonfiction. Offer the PDF as a companion, not as the main ebook for reading.

If you remember nothing else, remember this: reflowable formats are for reading, fixed layouts are for looking. Pick the format that matches how your reader will hold the book. Your reviews will thank you.

Choosing the Right Format for Your Book Type (Reflowable vs Fixed Layout)

Format choice comes down to one question.

Do you want the reader to control the page, or do you need to control the page?

If the reader controls the page, you want a reflowable ebook, usually EPUB. If you need to control the page because the layout carries meaning, you are looking at fixed layout, either fixed-layout EPUB or PDF.

The mistake I see all the time is authors picking a format based on fear. Fear of conversion. Fear of fonts shifting. Fear of a chart looking odd. So they shove everything into a PDF and call it done. Then readers open it on a phone and leave a review that politely translates to "I hated this experience."

Let's keep you out of that mess.

Reflowable: built for reading

A reflowable ebook treats your text like water. Pour it into a small glass, it takes the shape. Pour it into a big one, same deal.

Your reader changes font size, line spacing, margins, orientation, or background color. The book behaves. The pages are not "pages" in the print sense, they are screens of text.

This is why reflowable ebooks are the default for:

If your book is mostly paragraphs with the occasional heading and list, you will get the best reader experience with reflowable.

A quick gut check: if you would be fine reading your book in a plain, clean font on a Kindle Paperwhite, you are in reflowable territory.

Fixed layout: built for design-dependent content

Fixed layout locks the design in place. Text sits where you put it. Images stay aligned. Columns stay columns. A page is a page.

This matters when the layout does more than look nice. It carries information.

Fixed layout earns its keep in books like:

The cost is flexibility. On smaller screens, fixed layout often means zooming and panning. Some readers tolerate that for a comic. They will not tolerate it for a novel.

So use fixed layout when you must, not when you feel nervous.

The three things that decide your format

You do not need a technical background to choose wisely. You need to look at your manuscript like an editor, not like a proud parent.

1) Tables, charts, images, callouts, sidebars

These elements do fine in reflowable ebooks when they are simple.

A single chart image with a caption, fine. A short table with two columns, sometimes fine, depending on the device. But the more your content depends on "this sits next to this," the more reflowable starts to strain.

Here's the practical test. Open your manuscript and find the most complex spread, the one you worry about.

Now ask:

If the answers look ugly, consider a fixed-layout edition, or rethink how you present the information. Sometimes the best fix is not a new format, it's redesigning the content. Turn a wide table into a list. Split one giant chart into two. Move detail into an appendix.

2) Typography and special characters

Poetry is the classic troublemaker, and I say that with affection.

Line breaks, indentation patterns, unusual spacing, and deliberate placement all matter. Reflowable ebooks try to respect those choices, but different devices interpret styling in different ways. You can get close, yet "close" might not be good enough for a poem where one shifted indent changes the reading.

Other typography red flags:

This does not mean you must abandon reflowable. It means you should test early, and you might decide to publish two editions. One reflowable for general reading, one fixed layout for readers who need the exact visual presentation.

3) Navigation: table of contents, footnotes, endnotes, cross-references

Navigation is where ebooks either feel professional or feel like a bad photocopy.

Reflowable EPUB does navigation well when your file is built cleanly. Linked table of contents. Tap a chapter title, you go there. Tap a footnote, you jump to it and back again. Readers love this because they never lose their place.

Fixed layout varies. A PDF can support links, yet many PDFs in the wild are "flat." No meaningful bookmarks. No internal links. Nothing to help a reader move through a long book without endless scrolling.

If your nonfiction relies on frequent reference, you should care about navigation as much as you care about layout. A beautiful design with terrible navigation still frustrates readers.

When two editions are the smart move

Sometimes the right answer is not choosing one format, it's choosing two.

Here are common pairings that work well:

If you go with two editions, be clear in your product description. Tell readers what each file is for. You are not adding complexity, you are preventing refunds.

Keep your files lean, or retailers will punish you

Ebooks are not the place to dump 40 high-resolution images and hope for the best.

Large files mean slower downloads, sluggish page turns, and in some stores, higher delivery fees deducted from your royalties. That last one tends to get an author's attention.

A few practical habits:

If you are offering printables, consider keeping them in a separate PDF bonus file rather than stuffing them into the ebook itself. Readers who

Where Each Format Is Used (Amazon KDP, Ingram, Kobo, Apple, Google)

If ebook formats were house keys, EPUB would open most doors. Amazon is the one neighbor who changes the lock and insists you use their key, even when you show up holding a perfectly good one.

So let's talk about where each format goes, what each store expects, and where writers tend to trip.

Amazon KDP: bring EPUB, Amazon does the rest

Amazon sells ebooks to Kindle devices and Kindle apps, and those run on Amazon's own Kindle formats under the hood.

Here's the part many authors miss: KDP accepts an EPUB upload. You do not need to upload a MOBI file (those days are over), and you do not need to stress about producing an AZW file yourself. You upload EPUB, Amazon converts it, and the customer gets a Kindle-friendly file.

That conversion step is the whole story.

Sometimes it goes smoothly. Sometimes Amazon makes "helpful" choices about spacing, indents, scene breaks, font styling, or how it handles a fancy table you worked too hard on. Your job is to catch those choices before readers do.

Kindle Previewer: your best friend with a harsh personality

Amazon gives you Kindle Previewer for a reason. Use it.

Preview your book on:

Then look for the usual suspects:

A small habit that saves you hours: every time you upload a revision to KDP, download the preview file again and check the same problem spots. Conversions vary across versions. Yes, it's annoying. No, Amazon does not care about your feelings.

Apple Books, Kobo, Google Play Books: EPUB feels at home

If you're selling outside Amazon, you're in EPUB country. Apple Books, Kobo, and Google Play Books all prefer EPUB, and in my experience, they tend to display a clean EPUB with fewer unpleasant surprises.

That does not mean "no surprises." It means the workflow makes sense.

A good EPUB, built with proper styles and a working table of contents, usually behaves across these stores in a predictable way. So when people say "EPUB is the standard," this is what they mean in practice.

A few practical notes:

If your plan is "publish wide," treat your EPUB as your master file. Keep it clean. Keep it validated. Make changes there first, then upload.

Aggregators: Draft2Digital, Smashwords, StreetLib (and why you might want one)

Uploading direct to every retailer gives you control. It also gives you five dashboards, five sets of metadata fields, five pricing pages, and five places to forget to update your blurb.

Aggregators exist because authors got tired.

A distributor like Draft2Digital (which now includes Smashwords in the same family) or StreetLib takes your EPUB, sometimes a Word file, then delivers your book to multiple retailers. You manage one upload, one metadata form, and one update process.

The trade-offs are simple:

If you love control and you like tweaking pricing and promos per store, go direct. If you want fewer moving parts, pick an aggregator and spend your time writing the next book.

One caution: do not assume "aggregator" means "every store on earth." Always check their current list of partners, and check whether you will still be able to access key promo tools in each retailer.

Ingram: mostly a print conversation, but it still touches ebooks

Ingram comes up constantly in self-publishing circles, usually because of print distribution through IngramSpark. For ebooks, Ingram has distribution options too, but most indie authors build their ebook plan around Amazon plus the main wide retailers, either direct or through an aggregator.

Here's the useful way to think about Ingram in an ebook formats post: if your goal is wide reach, EPUB remains the working file. Your distribution route is the variable, not the format.

If you are already using IngramSpark for print and you want a single ecosystem, look at their ebook distribution terms with a clear head. Compare royalty rates, pricing control, and update speed. Choose based on business, not convenience.

The decision that matters more than file type: Select or wide

Writers get stuck debating EPUB versus Kindle formats as if the file extension is the big strategic choice. It's not.

The big strategic choice is exclusivity.

Notice what's missing from that list. File type drama. You can publish with EPUB either way.

So decide early. It affects your timeline, your launch plan, and whether you build readership outside the

Formatting and Conversion: How to Create Professional Ebook Files

Ebook formatting has one ruthless rule: if you fake order on the page, the file will punish you later.

On your laptop, a string of spaces might line up. In an ebook, those spaces turn into chaos the moment a reader bumps the font size up two notches or switches from portrait to landscape. Your goal is not to make the manuscript look nice in Word. Your goal is to build a file that behaves.

Let's talk about the main ways authors get from manuscript to EPUB, and what "professional" looks like when you pop the hood.

Three common creation routes (and who each one suits)

1) Word or Google Docs → template → export to EPUB

This route works best for straightforward books. Think novels, memoirs, plain nonfiction.

The danger is not Word itself. The danger is how people use Word.

If your document is full of:

…then exporting to EPUB is like pouring soup into a suitcase. Something will leak.

If you want this route to behave, treat Word like a structure tool. Use styles. Keep formatting boring. Let the ebook reading system handle the visual side.

A quick self-test: click into a normal paragraph and then into a chapter title. If both are "Normal" with different manual tweaks, stop and fix it. Your future self will thank you.

2) Vellum (Mac) / Atticus (web) / Scrivener (varies)

These tools exist because ebook code is finicky and writers have better things to do.

These tools do not remove the need for good input. If your manuscript is messy, they will export a tidy-looking mess. The mess is now hiding in the file.

3) Professional formatter

If your book has complex elements, a pro is often the cheapest option in the long run.

"Complex" usually means:

A formatter earns their fee by preventing retailer conversion problems, cleaning the structure, and producing files that pass checks. They also tend to spot the weird little issues authors miss, like a table of contents that looks fine but does not link properly on half the devices.

If you hire a formatter, ask what files you will receive. At minimum, you want the final EPUB and a clear process for updates.

The formatting essentials that separate clean ebooks from messy ones

Use paragraph styles, not manual formatting

Styles are boring. Styles are also the difference between "works everywhere" and "why is chapter three in italics."

Set up styles for:

Then apply them consistently. Consistently means every time, even when you are tired.

Here's a fast exercise. Open your manuscript and turn on formatting marks. In Word, that's the paragraph symbol. Now scan a chapter opening.

Your ebook file needs semantic structure. A bolded line is not a heading. A heading style is a heading.

Build a real, linked table of contents

Readers use the table of contents the way drivers use road signs. If yours is broken, they blame you, not the device.

A proper ebook TOC should:

Do not type a TOC by hand and assume the export will link it. Some tools will, many will not, and the failures are sneaky.

After export, click every TOC entry. Every one. Yes, all of them. This is the easiest way to catch a structural problem early.

Clean chapter breaks, clean scene breaks

Chapter breaks should be consistent. Pick a method and stick to it.

Avoid "spacing" your way into a chapter break by hitting Enter until the next page appears. Ereaders do not care about your Enter key.

Keep fonts simple, and keep styling light

Most readers change fonts. Many override your spacing. Some force night mode. Your job is to avoid fighting those settings.

A few practical rules:

Every extra styling choice is one more chance for a device to misbehave.

Start with a clean manuscript (before you export)

This is the part authors skip because it feels like housekeeping. Housekeeping is what separates a smooth EPUB from a file held together with duct tape.

Before you export: