Adage Usability
- Providing usability services such as heuristic evaluation and usability testing, based in Finland.
- http://www.adage.fi/

Web Usability, the Right Way
- Consultant service provides a service to make websites stand out from the competition by making them more user friendly, based in USA.
- http://webusabilitytherightway.com/

Atlantic Human Factors
- Usability consultancy focused on understanding user behavior, abilities, and skills and applying that knowledge to the design of efficient and easy to use interfaces and workflows. Based in Florida, USA.
- http://www.atlantichumanfactors.com/

Hawdale Associates Limited
- Consulting firm focused on helping clients understand how customers think and buy online and how to design online experiences that work, based in Manchester, United Kingdom.
- http://www.hawdale-associates.co.uk

UsabilityReviews
- Offers website optimization services, based in Ontario, Canada.
- http://www.usabilityreviews.com

User Centric, Inc.
- User experience consulting firm that specializes in usability testing, user experience research and design, based in Illinois, USA.
- http://www.usercentric.com/

MicroUsability
- User experience testing, consulting and design. Offices in Singapore, Malaysia, Vancouver and the United Arab Emirates.
- http://www.microusability.com/

The Site Therapist
- Website prognosis reports that include information pertaining to the health of websites, based in Cary, North Carolina, USA.
- http://www.thesitetherapist.com/

Metro Research Ltd
- International market research and usability consultancy based in the United Kingdom.
- http://www.metroresearch.com/

Interface IQ
- Independent specialist usability, accessibility and information architecture consultancy based in Northern Ireland.
- http://www.interfaceiq.com/

TandemSeven
- Design and usability services covering the full application development lifecycle, based in the USA.
- http://www.tandemseven.com/

PinPoint Performance Solutions
- Usability testing and needs analysis to support user-centered design and performance improvement based in Idaho, USA.
- http://www.pinpointperformance.net/

infoDesign
- Information designers, technical writers and web usability analysts, based in Dunedin, New Zealand.
- http://www.infodesign.co.nz/

Peak Usability
- User experience and usability consultancy based in Brisbane, Queensland, Australia.
- http://www.peakusability.com.au

Experience Dynamics
- Professional usability and user centered design consultancy based in Oregon, USA.
- http://www.experiencedynamics.com

framfab
- Full service digital agency network servicing clients with marketing and technology solutions, based in the United Kingdom
- http://www.framfab.co.uk/

ResearchHouse
- Unique, usability testing facility built into a home setting, based in San Jose, California, USA.
- http://www.researchhouse.com

IQ Intelligent Internet
- Provides companies and government organisations with usability testing and evaluation services, based in Woden, Australia.
- http://www.iqi.com.au/index.shtml

UsabilityEffect
- Web site usability testing and newsletter conversion checkups, based in Pennsylvania, USA.
- http://www.usabilityeffect.com/

First Insights
- Conducts usability testing and qualitative market research, based in New York, USA.
- http://www.firstinsights.com

North Square
- Offers Web site evaluation reports based on navigation, design, content and strategy, based in Wellingborough, United Kingdom.
- http://www.north-square.com

Web Scrutineer
- Provides website testing for businesses and web developers, based in Auckland, New Zealand.
- http://www.webscrutineer.com/

Web Critiques
- Providing web critiques highlighting the good and bad points about a web site as well as techniques to fix them, based in the United Kingdom.
- http://www.webcritiques.net/

UserMetrics
- Offers to test web sites on people and applies insights from cognitive science for usability problems, based in the United Kingdom.
- http://www.usermetrics.net/

theSiteDoctor
- Provides website evaulations and usability testing, based in North Carolina, USA.
- http://thesitedoctor.com/

HT Consulting
- Provides usability assessment of web sites, software and computer-related hardware, based in California, USA.
- http://www.htamler.com/

Gokin, Paul
- Offers usability evaluations of web sites and applications, based in Vermont, USA.
- http://www.paulgokin.com

Breakthrough Usability, Inc.
- User performance testing services, based in Florida, USA.
- http://www.breakthroughusability.com/

Bolt and Peters User Experience
- A user-centered design firm specializing in remote usability testing and ethnogaphic research, based in California, USA.
- http://boltpeters.com/

Alertus
- Automated feedback system for collecting web usability and performance data, based in Washington, USA.
- http://www.alertus.com/

Afflatus Inc
- Evaluation of usability, information architecture, and the accessibility of sites, based in Dubai, United Arab Emirates.
- http://www.afflatusinc.com/