Convert EPUB to KEPUB Online — For 40-80x Faster Kobo Reading

Unlock better pagination, reading stats, and blazing-fast page turns.

Drop up to 50 EPUBs at once — no install, no sign-up required.

Drop EPUB Files Here

50 MB per file Up to 50 files 3 parallel conversions 1 credit per 10 MB

Encrypted EU Servers Auto-delete 1h

⚡ Median EPUB to KEPUB time (last 10k jobs): 31ms

How it works

1 · Drop your files
Drag & drop or choose EPUB files. No account required—paid plans unlock bigger batches, higher limits, and priority queues.
2 · We convert securely
Processed on our dedicated servers using kepubify. Encrypted in transit & at rest. We never store filenames—only file types & sizes for accounting.
3 · Download & auto-delete
Grab your KEPUB files in seconds. Files delete automatically after 1 hour. Delete anytime after downloading with one click.

About EPUB →

EPUB (Electronic Publication) is an open ebook standard developed by the International Digital Publishing Forum (IDPF), now part of the W3C. First released in 2007 as a successor to Open eBook, EPUB has become the most widely supported ebook format. EPUB files are ZIP archives containing HTML/XHTML content, CSS styling, images, and metadata organized according to the EPUB specification.

Learn more: EPUB on Wikipedia

EPUB's key feature is reflowable content—text automatically adapts to different screen sizes, making it ideal for e-readers, tablets, and phones. The format supports embedded fonts, multimedia (in EPUB 3), and accessibility features. Most e-readers except Amazon Kindle natively support EPUB.

About KEPUB

KEPUB (Kobo Enhanced Publication) is Kobo's proprietary ebook format, designed specifically for their e-readers. KEPUB files use the double extension .kepub.epub and are internally similar to standard EPUB, but include sentence-level <span> markup that enables Kobo-specific optimizations.

Learn more: KEPUB on MobileRead Wiki

The key benefits of KEPUB over standard EPUB on Kobo devices include: 40-80x faster page rendering, accurate reading time estimates, better pagination (no mid-sentence page breaks), and improved reading statistics. KEPUB files can only be fully utilized on Kobo e-readers—other devices should use standard EPUB.

Frequently Asked Questions

What is KEPUB format?

KEPUB (Kobo Enhanced Publication) is Kobo's proprietary ebook format based on EPUB. It adds sentence-level markup spans that enable better pagination, reading statistics, and 40-80x faster rendering on Kobo eReaders. KEPUB files use the double extension .kepub.epub.

Why convert EPUB to KEPUB?

Performance. KEPUB files load significantly faster on Kobo devices. They also enable features like accurate reading time estimates, better pagination (no mid-sentence page breaks), and smoother navigation. If you own a Kobo eReader, KEPUB is the optimal format for your library.

What devices support KEPUB?

KEPUB is specifically designed for Kobo eReaders (Libra, Forma, Clara, Sage, Elipsa, etc.). The format is also supported by Kobo's desktop and mobile reading apps. Other e-readers like Kindle or generic EPUB readers should use standard EPUB files instead.

Can I convert DRM-protected EPUBs?

No. DRM-protected EPUB files (purchased from stores with copy protection) cannot be converted. You must remove DRM protection first using appropriate tools, or contact the publisher for a DRM-free version.

What does the conversion process do?

Our converter uses kepubify, the open-source EPUB→KEPUB conversion tool. It adds sentence-level <span> tags that Kobo readers use for pagination and statistics. The original text content, images, and structure are preserved—only the markup is enhanced.

Will my reading progress be preserved?

Converting an EPUB to KEPUB creates a new file. If you've already started reading the original EPUB on your Kobo, you'll need to re-sync your progress manually or start fresh with the KEPUB version.

How do I sideload KEPUB files to my Kobo?

Connect your Kobo via USB and drag KEPUB files directly to the root folder or any subfolder. Kobo will detect the .kepub.epub extension and process them automatically. You can also use Calibre with the Kobo driver—it handles KEPUB conversion and syncing in one step.

What's the difference between KEPUB and regular EPUB on Kobo?

KEPUB adds sentence-level markup that Kobo's firmware uses for 40-80x faster page rendering, accurate reading time estimates, and improved pagination (no mid-sentence page breaks). Standard EPUBs work on Kobo but lack these optimizations—especially noticeable on older devices.

Can I convert KEPUB back to standard EPUB?

Yes. KEPUB is just EPUB with extra <span> tags and a special filename. Rename book.kepub.epub to book.epub and most readers will open it. For a cleaner file, use Calibre to strip the Kobo markup during conversion back to EPUB.

What are the limits for this converter?

Tier	Max File Size	Max Files/Batch	Parallel Processing
Free	50 MB	50 files	3 at once
Pro	200 MB	200 files	6 at once
Business	1024 MB	1000 files	10 at once

Note: File size limits are specific to this converter. Batch and parallel processing limits apply to all ebooks converters site-wide. See all converter limits →

How are credits calculated for this conversion?

Cost: 1 credit per 10 MB

How it works:

Files up to 10 MB: 1 credit (minimum)
11-20 MB: 2 credits
21-30 MB: 3 credits
31-40 MB: 4 credits
Over 1024 MB: 103 credits (maximum cap)

Example: A 5 MB file = 1 credit. A 95 MB file = 10 credits.

Why per-megabyte? Larger files require more resources (processing, bandwidth, storage).

What are my daily and monthly credit limits?

Credit allocations vary by account tier:

Tier	Daily Limit	Monthly Limit
Free	50 credits/day	—
Pro	—	10,000 credits/month
Business	—	25,000 credits/month

Daily credits (Free tier, including guests) reset every day at midnight UTC. Monthly credits (Pro & Business) reset on your billing cycle date.

Note: With 1 credit per 10 MB, images under 10 MB cost 1 credit each. Pro users can convert 10,000 images per month.

Answers at a Glance

Quick answers to common questions.

Related Ebook Converters

Looking for other Kindle formats? Try these converters.

EPUB MOBI

For older Kindle devices (pre-2012)

EPUB AZW3

For modern Kindles with better typography

Choose Your Plan

Limits shown for EPUB to KEPUB conversion. One subscription unlocks the entire Tools.FAST Network. Plans cover Convert.FAST, Compress.FAST, PDF.FAST (soon), and all future tools.

Monthly Annual 4 Months Free

Free

For occasional personal use

50 MB per file
50 files per batch
3 parallel standard conversions
2 parallel AI conversions
50 credits/day
Standard priority
Email support

No sign-up required.
Create an account for your own credit pool.

Popular

Pro

$9 /month

For independent work

200 MB per file
200 files per batch
6 parallel standard conversions
4 parallel AI conversions
10,000 credits/month across Tools.FAST
High priority
Email & chat support
One subscription for the entire Tools.FAST network

Business

$19 /month

1 seat

For production scale

1 GB per file
1000 files per batch
10 parallel standard conversions
6 parallel AI conversions
25,000 credits/month across Tools.FAST
Add seats to invite team members
Highest priority
Priority email & chat support
One subscription for the entire Tools.FAST network

How Credits Work

Usually 1 credit per conversion. Exact cost shown before you start.
Credits refresh monthly on your billing cycle.
Unused credits roll over, capped at your plan's monthly amount.
One subscription, all sites. Works across Convert.FAST, Compress.FAST, and future tools.

View all Convert.FAST limits by tier → View all Compress.FAST limits by tier →

What's New in EPUB to KEPUB

Latest improvements to this converter

Last updated January 16, 2026

Jan 16, 2026

Initial release of EPUB to KEPUB converter for Kobo eReader optimization.