A collection of devices showing the Colibrio Reader in action

Trusted by

Logos from companies that use the Colbrio Reader. The logos are Nationale Bibliotheek van Nederland, Aerio, De Marque, Rosen Publishing, Publizon A/S, Ubook and Ibtikar

and many more

Colibrio Reader Framework

Digital Reading Experiences
The Reading System

Colibrio Reader is a new, innovative Reading System SDK built on the Modern Web Platform. It is a web first engine, developed using the latest technologies and practices, built to support new upcoming standards, as well as the current publishing formats.

Colibrio Reader excels on any platform and performs equally well on mobile as on desktop.

Colibrio Reader is a new, innovative Reading System SDK, built on the Modern Web Platform

Colibrio Reader Framework lets you build solutions that push the limits of the digital reading experience.

  • One Framework, all Platforms
  • Native and Browser Apps
  • Multi-format (EPUB, PDF, etc)
  • Scripting and Interactivity
  • Video, Audio, Animation
  • Media Overlays
  • Text to Speech
  • Annotations
  • Full-text Search
  • Managed Styling
  • EPUB Streaming
  • Unmatched Pagination Quality
  • Web Publication Audiobooks
A screenshot of a reflowable EPUB as displayed in the Colibrio reader
Screenshot from a reflowable EPUB3
A screenshot of a fixed layout EPUB3 as displayed in the Colibrio reader. The document contains interactive features such as video and integrated Spotify playback.
Screenshot from a fixed layout EPUB3

Reader Experience First

Book design is a craft. It has been perfected since the early days of writing to help make the experience of reading captivating and immersive. Colibrio Reader focuses on preserving authors, publishers and designers original formatting and visual style. 

To bring e-book page layout closer to what you expect from a page in a printed book, we at Colibrio have developed a unique solution for flowing content across pages called Colibrio Reflow.

Colibrio Reader focuses on preserving authors, publishers and designers original visual style

We offer the only Reading System which can configure detailed rules for pagination to avoid orphans, widows, split boxes and much more, regardless of document structure and semantics.  

Accessibility First

Accessibility is a foundational property of the Colibrio Reader Framework. Our technology helps build more inclusive ecosystems of products and services for all readers, regardless of their needs.

We have built in support for Media Overlays, Text to Speech, user definable type and display settings and more. We also expose "low level" accessibility platform technologies, so that you have all that you need to innovate and create.

Screenshot from a EPUB3 with active Media Overlays.
Screenshot from a Daisy EPUB3 with Media Overlays

Futureproof Design

Colibrio Reader is designed and built to be highly adaptable. It handles different publication formats using so called Format Adapters. An adapter takes a publication such as an EPUB or PDF and makes its contents available to the Reading System in a generalized way. EPUB3, PDF and Web Publication Audiobooks are supported out of the box, but any future format is only a new adapter away!

EPUB3, PDF and Web Publication Audiobooks are supported out of the box, but any future format is only a new adapter away!

Examples of other aspects of the Reading System which are also adapter based are DRM, Annotation and Bookmarking Services.

Screenshot from a PDF publication showing a spread of a wonderful Icelandic view.
Screenshot from PDF publication
A Screenshot of a code example showing how to set up a reading system using just a few lines of code.
Screenshot of code example

Developer Friendly

Colibrio Reader is written in TypeScript with native development kits in Kotlin and Swift. The developer API is designed to be unified across all platforms so that your team can comunicate concepts and solutions cross platform.

You can easily extend and configure all aspects of the framework to fit your application. This applies to such things as user authentication, DRM services, persistance, event handling and of course all things User Interface related.

You can easily extend and configure all aspects of the framework to fit your application

The loosely coupled architecture allow you to build anything from a headless rendering service in the cloud, a web based reading system, to a cutting edge e-reader for any native platform!

Use Cases


One of the most obvious use cases for a Reading System engine is as the heart of an E-reader. Colibrio Reader is a perfect fit and gives an extra competitive edge, regardless of platform and screen technology.

Ebook retailers

More and more ebook retailers and publishers are offering the possibility to read parts of, or entire publications online. Colibrio Reader offers an unmatched feature set for a browser based Reading System.

Library systems

With Colibrio Reader libraries can offer online or in-app lending and reading for any type of publication.

E-Learning systems

EPUB 3 is an ideal format for e-learning material. Having a learning platform which uses standardized formats can greatly streamline production, life cycle management, reuse and distribution of learning material. Using features such as annotations and social reading will add extra dimensions to the learning experience.

Document Management systems

With Colibrio Reader, Document Management systems can support viewing of all major standard distribution formats for ebooks.

Browser vendors 

Natively supporting EPUB in browsers will be more important as we move closer to the realisation of the Web Publications standard. Using the Colibrio Reader SDK, vendors can do what Microsoft Edge already has done and support opening and reading EPUB directly in the browser.

Print-on-demand solutions

Because of its versatile, component oriented design Colibrio Reader can be used “headless” on the server as a rendering engine for printable PDFs. Thanks to its unique reflow features, Colibrio Reader can produce well balanced pages, even for complex page layouts