I have collected 17 free ebooks about UX and interface design, including some best selling books which are definitely worth reading. Not only are these free ebooks pretty good reads but perhaps I’ll save a small rainforest as well. In case you’ve come across some other free ebooks, let us know.

1. Search User Interfaces by Marti A. Hearst

If you want to design innovative search user interfaces, you need this book close at hand at all times. Read Search User Interfaces.

2. Web Style Guide by Patrick J. Lynch and Sarah Horton

A style guide for the interface with real long-run value, showing us deep principles of design rather than simply fashion and technology. Read Web Style Guide.

3. The Agile UX Best Practices Bundle by UXPin

This bundle consists of 3 ebooks, all about the agile UX process. Read about the best practices for user research, prototyping, iteration, usability testing, documentation, and more. Read The Agile UX Best Practices.

4. Designing Interfaces – Patterns for Effective Interaction Design by Jenifer Tidwell

Anyone who’s serious about designing interfaces should have this book on their shelf for reference. Read Designing Interfaces.

5. Designing Mobile Interfaces by Steven Hoober and Eric Berkman

This practical guide teaches you the core principles for designing effective mobile user interfaces, and helps you get started by providing more than 40 proven UI patterns for mobile websites and applications. Read Designing Mobile Interfaces.

6. Just Ask: Integrating Accessibility Throughout Design by Shawn L. Henry

A focus on accessibility during the entire user-centered design process. Read Integrating Accessibility Throughout Design.

7. Converting the Believers by Usereffect

Turn believers into buyers and maximize your website’s ROI. Learn how to use analytics, usability and testing to systematically improve online sales. Read Coverting the Believers.

8. Task-Centered User Interface Design by Clayton Lewis and John Rieman

This report is based on 8 series of usability studies with users in 4 countries reporting how they actually used a broad variety of websites and apps on a range of mobile devices, including touch phones and smartphones from many vendors. Read Task-Centered User Interface Design.

9. User Centered Design – The Fable of the User-Centered Designer by David Travis

After reading this 40-page fable, you’ll understand the framework of user-centred design and know how to apply it to your own design project. Read User Centered Design.

10. Six Circles – An experience design framework

Have you noticed how UX and consumer products or services are quickly becoming intertwined, basically the same thing? This ebook will provide you with a framework for how to create and utilize an experience design framework in your organization. Read Six Circles.

11. UX Storytellers – Connecting the dots by 42 UX masterminds

42 UX masterminds tell personal stories of their exciting lives as User Experience professionals. Read UX Storytellers.

12. Getting Real by 37signals aka BaseCamp

Basecamp, formerly known as 27 Signals, created a great ebook, consisting of 16 chapters and 91 essays. Really worth your time. Read Getting Real.

13. Designing for the Web by Five Simple Steps and Mark Boulton

Author Mark Boulton takes an approach that includes researching the usage of the site, understanding typography, utilizing color for navigation as well as presentation and creating a usable and satisfying layout. Read Designing for the Web.

14. The UX Reader by Mailchimp

Maybe you have already heard about Mailchimp? Then you might have heard that Mailchimp is pretty serious when it comes down to UX. This free ebook is a collection of the most popular articles from their UX Newsletter, along with some exclusive content. Read The UX Reader.

15. How to Recruit Participants for Usability Studies by Deborah Hinderer Sova and Jacob Nielsen

Whether you’re just starting out in usability, or a long time veteran, you no doubt face the same hurdle of where to find and recruit good usability participants. This free eBook will show you how. Read How to Recruit Participants for Usability Studies.

16. Knock Knock: An Incomplete Guide to Building a Web Site that Works by Seth Godin

Seth Grodin is the guru of market, just like Jakob Nielsen is to usability. Although published way back in 2005, it’s still an interesting read! Read An Incomplete Guide to Building a Web Site that Works.

17. Mental Models in Human-Computer Interaction by John M. Carroll and Judith Reitman Olson

Research issues about what the user of software knows. Read Mental Models in Human-Computer Interaction.

18. Bonus: The Basics of User Experience Design by Interaction Design Foundation

In 9 chapters, they cover the following topics: conducting user interviews, design thinking, interaction design, mobile UX design, usability, UX research, and many more! Read The Basics of User Experience.

Editorial note: I have also collected some free ebooks about Usability. Are ebooks not your cup of tea and you prefer to smell real paper, then maybe you can have a look at my UX book collection.