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Publishing · head to head

Kindle Direct Publishing vs Sigil

Kindle Direct Publishing logo

Kindle Direct Publishing

Publishing

Amazon self-publishing platform that is free to use, earning Amazon a royalty cut instead of a fee, with a hard price band and per-megabyte delivery cost governing the 70% rate

From
Free
Rated
-
Full reviewWebsite
Sigil logo

Sigil

Publishing

Open source EPUB editor for working directly on the file, not generating it

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Kindle Direct Publishing the 70% royalty band has hard edges: pricing even one cent outside $2.99-$12.99 drops the royalty to 35%, which is a cliff, not a gradual scale, and easy to trigger by accident when adjusting price for a promotion.; Sigil it produces no print output whatever, so any book that needs a paperback interior requires a completely separate tool and a second workflow.
  • They diverge on capability: Kindle Direct Publishing covers Free publishing, Sigil covers Direct EPUB editing.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Kindle Direct Publishing and Sigil actually diverge.

Attributes where Kindle Direct Publishing and Sigil differ
AttributeKindle Direct PublishingSigil
Pricing modelFree to publish; Amazon earns a royalty share rather than a feeOpen source, no licence fee
PlatformsWebWindows, macOS, Linux

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Publishing).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Kindle Direct Publishing

  • Free publishing
  • 70%/35% royalty tiers
  • Print-on-demand
  • KDP Select
  • Delivery fee deduction
  • Pre-order and release tools

Only in Sigil

  • Direct EPUB editing
  • Code and preview views
  • EPUB 2 and EPUB 3
  • Regex across files
  • Validation
  • Python plugins

What people use each for

The jobs each tool is most often brought in to do.

Kindle Direct Publishing

  • A self-published author wanting free, no-fee distribution to the largest single ebook and print-on-demand marketnot Sigil
  • An author pricing a book between $2.99 and $12.99 to qualify for the 70% royalty tier rather than 35%not Sigil
  • A publisher considering KDP Select exclusivity to earn Kindle Unlimited page-read royalties, trading away distribution on other retailers for the enrollment periodnot Sigil
  • An author with a large, image-heavy ebook file who needs to understand the per-megabyte delivery fee before setting a pricenot Sigil

Sigil

  • Fixing an EPUB that a retailer validator has rejected, without re-exporting from the tool that generated itnot Kindle Direct Publishing
  • Correcting the table of contents, reading order or metadata in a file supplied by a conversion servicenot Kindle Direct Publishing
  • Preparing a back-catalogue title where the only surviving source is the EPUB itselfnot Kindle Direct Publishing
  • Applying a consistent stylesheet or a bulk text correction across every chapter of a book at oncenot Kindle Direct Publishing

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Kindle Direct Publishing

  • The 70% royalty band has hard edges: pricing even one cent outside $2.99-$12.99 drops the royalty to 35%, which is a cliff, not a gradual scale, and easy to trigger by accident when adjusting price for a promotion.
  • The delivery fee, roughly $0.15 per megabyte, is deducted on every sale under the 70% tier, so image-heavy or long ebooks lose meaningfully more revenue per sale than a plain-text book at the same list price.
  • KDP Select exclusivity, while optional, is the only route to Kindle Unlimited page-read royalties, so authors face a real trade-off between Amazon-only reach with page-read income and wider distribution without it.
  • Public domain or primarily public-domain content is capped at the 35% royalty regardless of price, so that category of publisher cannot access the higher rate at all.
  • As a single-retailer platform, an author relying solely on KDP is concentrated in one sales channel controlled entirely by Amazon policy, which has changed royalty terms before (the July 2026 price band expansion is itself an example) and can do so again.

Sigil

  • It produces no print output whatever, so any book that needs a paperback interior requires a completely separate tool and a second workflow.
  • Meaningful use requires reading and writing HTML and CSS, which puts it out of reach of most authors who simply want a finished file.
  • There is no cloud storage, sync or collaboration, so the book exists as a file on one machine and version control is whatever you set up yourself.
  • Development depends on a small number of volunteer maintainers, so release timing and platform builds follow their availability rather than a roadmap, and a lapse in maintenance would leave no obvious successor.
  • It provides no distribution, no retailer connection and no Kindle-native output, so it sits in the middle of a workflow that other tools have to complete on both sides.

Pricing, plan by plan

Kindle Direct Publishing

Free
  • 70% royalty tierFree
    • Applies to ebooks priced $2.99-$12.99 (expanded from $9.99 ceiling in July 2026)
    • In-copyright works only
    • Delivery fee of roughly $0.15/MB deducted per sale
  • 35% royalty tierFree
    • Applies below $2.99, above $12.99, or for public domain content
    • No delivery fee deducted
    • Applies automatically outside eligible territories for the 70% tier

Sigil

Free
  • SigilFree
    • GPL licensed with no cost or account required
    • Full functionality with no feature gating
    • Community support through forums and the issue tracker

Which should you pick?

Choose Kindle Direct Publishing if

  • You need free publishing.
  • You want to start without paying.
  • You also want 70%/35% royalty tiers.
Kindle Direct Publishing review

Choose Sigil if

  • You need direct epub editing.
  • You want to start without paying.
  • You work on Windows, macOS, Linux.
  • You also want code and preview views.
Sigil review

Questions people ask

Is Kindle Direct Publishing or Sigil better?
Neither clearly leads. Kindle Direct Publishing starts at Free and Sigil at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Kindle Direct Publishing or Sigil?
Kindle Direct Publishing starts at Free and Sigil at Free.
Does Kindle Direct Publishing or Sigil run on more platforms?
Kindle Direct Publishing runs on Web. Sigil runs on Windows, macOS, Linux.
Can I use Kindle Direct Publishing for free?
Both have a free tier, so you can try either at no cost before committing.
What is Kindle Direct Publishing best used for?
Kindle Direct Publishing is most often used for a self-published author wanting free, no-fee distribution to the largest single ebook and print-on-demand market, an author pricing a book between $2.99 and $12.99 to qualify for the 70% royalty tier rather than 35%, a publisher considering kdp select exclusivity to earn kindle unlimited page-read royalties, trading away distribution on other retailers for the enrollment period, an author with a large, image-heavy ebook file who needs to understand the per-megabyte delivery fee before setting a price. Of those, a self-published author wanting free, no-fee distribution to the largest single ebook and print-on-demand market and an author pricing a book between $2.99 and $12.99 to qualify for the 70% royalty tier rather than 35% are not what Sigil is typically brought in for.
What can Kindle Direct Publishing do that Sigil cannot?
Kindle Direct Publishing covers Free publishing, 70%/35% royalty tiers, Print-on-demand, KDP Select. Sigil covers Direct EPUB editing, Code and preview views, EPUB 2 and EPUB 3, Regex across files.

Answered from the vendors’ own pages

Kindle Direct Publishing: Does KDP cost anything to use?

No signup or listing fee. Amazon earns revenue through the royalty share (65% or 30% of the list price after territory and delivery-fee adjustments) rather than a subscription or fee.

Sigil: Can I write my book in Sigil?

You can, but you should not. It is an EPUB editor, not a word processor, and writing long-form prose in it is unpleasant. Write elsewhere, import, then finish in Sigil.

Kindle Direct Publishing: What is the current 70% royalty price band?

As of July 2026, $2.99 to $12.99, expanded from the previous $2.99 to $9.99 ceiling that had been unchanged since 2007.

Sigil: Does it make Kindle files?

Not natively. Produce a valid EPUB in Sigil and let Amazon convert it, or use a separate conversion tool for other Kindle formats.

Kindle Direct Publishing: What is the delivery fee?

Roughly $0.15 per megabyte of file size, deducted per sale only on the 70% royalty tier, calculated from the delivered file size.

Sigil: Is it safe to rely on a volunteer project for commercial work?

The files it produces are standard EPUB, so nothing is locked in. The risk is that maintenance stops, not that your books become unreadable.

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