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Top #2 Web Development Company in the world

We are big on creating eminently successful businesses - products we have developed from scratch so far have raised in excess of $495,000,000 in funding!

No one failed projects

In addition, we were named as "Best & innovative development company on the market" (c) RBC

Plus, we became "Top #2 Web Development Company in the world" (c) Manifesto

Under-the-hood:

  • Min project size
    $10,000+
  • Hourly rate
    $50 - $99 / hr
  • Employees
    50 - 249
  • Locations
    London, England
  • Year founded
    Founded 2008

1 Locations

  • London , England

Select Focus Area
Application Platforms
Amazon Application Development Framework
40%
Heroku
20%
General Accounting Focus
Frameworks and CMS
Programming & Scripting
PHP
50%
Ruby
30%
Industries
Financial services
25%
Education
20%
Medical
20%
Business services
10%
Consumer products & services
10%
Information technology
10%
Other industries
5%
Clients
Midmarket ($10M - $1B)
40%
Small Business (<$10M)
40%
Enterprise (>$1B)
20%

Pricing Snapshot

Min. project size $10,000+
Avg. hourly rate $50 - $99 /hr
Rating for cost 4.8 /5

What Clients Have Said

4xxi offers competitive pricing, with project costs ranging from $17,250 to over $240,000, depending on the complexity and scope. Clients appreciate their value for cost, citing high-quality work and effective communication, often at a fraction of U.S. prices.

This summary is based on verified Clutch reviews.

Most Common Project Size

$50,000 - $199,999 based on 9 reviews
< $49,999 $50,000 - $199,999 $200,000 - $999,999 > $1,000,000

Select a service to see pricing information

Highly Rated Similar Providers

4xxi Review Insights

Overall Review Rating

4.9
  • Quality 4.9
  • Schedule 4.8
  • Cost 4.8
  • Willing to Refer 4.9

Top Mentions

Review Highlights

  • Expertise in Diverse Industries

    4xxi has successfully delivered projects across various industries, including financial services, education, media, and technology, showcasing their adaptability and industry-specific knowledge.

  • Project Management Improvements Needed

    Some clients experienced initial challenges with project management, such as project manager turnover, but these were resolved over time, highlighting an area for potential improvement.

  • Commitment to Timelines

    4xxi is commended for their commitment to meeting project deadlines, often delivering projects on time or ahead of schedule, which is crucial for clients with tight timelines.

  • Strong Communication and Collaboration

    Clients consistently praise 4xxi for their effective communication, responsiveness, and collaborative approach, ensuring smooth project progress and alignment with client goals.

  • Flexibility and Adaptability

    4xxi demonstrates flexibility in adjusting to client needs and project changes, making them a reliable partner for dynamic and evolving projects.

  • Client-First Approach

    4xxi prioritizes client needs and satisfaction, often tailoring their approach to align with client preferences and project requirements, fostering strong partnerships.

4xxi Reviews

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Services
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Industry
Location

Mobile App Dev for Social Platform

  • Mobile App Development
  • $200,000 to $999,999
  • Jan. 2020 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"They are a fantastic team and we wouldn't be where we are today without them!"

Nov 11, 2020
Director & Co-Founder, Challenge Social
Josh Lewis
Verified
  • Other industries
  • United Kingdom
  • 1-10 Employees
  • Online Review
  • Verified

4xxi was hired by a social platform to redevelop their mobile app for iOS and Android. They were also tasked with coding their website and provide maintenance and support.

Custom Software Development for Advertising Firm

  • Custom Software Development
  • $200,000 to $999,999
  • June 2013 - Sep. 2017
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

“I was very impressed by the quality of their work and their development speed.”

Jul 24, 2018
VP of Engineering, Virool inc
Alexander Petrov
Verified
  • Advertising & marketing
  • San Francisco, California
  • 51-200 Employees
  • Online Review
  • Verified

4xxi provided UI development services for various customer dashboards for an online platform. The team created accessible and manageable dashboards for analytics, billing, campaign management, and reports.

Platform Dev for Auditing Firm

  • Web Development
  • $50,000 to $199,999
  • Feb. - May 2017
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"They can look at a startup from different angles and provide insight on how to improve."

Apr 20, 2018
Owner, Auditing Firm
Anton Petrov
Verified
  • Financial services
  • Russia
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi developed a complex platform for auditing services, handling the programming and design for the whole infrastructure. They provided all documentation and will handle the next version’s build in the future.

Intranet Dev for Private Investment Firm

  • Web Development
  • $50,000 to $199,999
  • Feb. 2015 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

“Working with 4xxi has been one of the best commercial experiences of my business life.”

Jan 19, 2018
President, Emanuel Quant Services
Steven Emanuel
Verified
  • Financial services
  • New York City, New York
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi integrated numerous data sources into one tool that displayed all the desired information in a singular report. The project consisted of an iterative and collaborative process.

Web Dev for VPN Firm

  • Web Development
  • Confidential
  • Mar. 2017 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

“4xxi builds software to their own quality standards, which are high even compared to Silicon Valley.”

Oct 20, 2017
Director of Product, AnchorFree
Sergey Fedorov
Verified
  • Other industries
  • San Francisco, California
  • 51-200 Employees
  • Phone Interview
  • Verified

4xxi assisted with a VPN website update. The team provided consultation guidance, then collaborated in designing and developing the new platform using PHP and JavaScript.

Web Dev for Financial Services Firm

  • Web Development
  • Confidential
  • Oct. 2015 - Ongoing
5.0
Quality
5.0
Schedule
4.5
Cost
5.0
Willing to Refer
5.0

"They are so responsive, thoughtful, great communicators, and really challenge and ask the right questions."

Sep 19, 2017
General Manager, WorthFM
Emily Jipson
Verified
  • Financial services
  • Philadelphia, Pennsylvania
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi built a robo-advisory platform using Ruby and React. They were responsible for project management, backend development, architecture, some design and QA.

Cross-Platform App Dev for Productivity App

  • Mobile App Development
  • Confidential
  • June 2013 - Ongoing
5.0
Quality
5.0
Schedule
4.5
Cost
5.0
Willing to Refer
5.0

“We would not be here today if 4xxi was not involved in this project.”

Sep 15, 2017
CEO, Productivity App
Anonymous
Verified
  • Other industries
  • New York City, New York
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi developed a cross-platform app for iOS, Android, and the web. The app is designed for coordinated communication in crisis situations. 

iOS and Android Native Dev for Concierge Service App

  • Mobile App Development
  • $50,000 to $199,999
  • Aug. 2016 - July 2017
5.0
Quality
4.5
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"[T]hey go that extra mile to answer questions and solve problems."

Sep 6, 2017
CEO, Iterium
Kirill Garbar
Verified
  • Other industries
  • London, England
  • Phone Interview
  • Verified

Using a framework built in PHP and Symfony, 4xxi built mobile concierge apps for the iOS and Android platforms. The projects involved continuous integration, back-end development, and scripting. 

Web Dev for Ratings & Reviews Platform

  • Web Development
  • $200,000 to $999,999
  • Sep. 2012 - Ongoing
4.5
Quality
4.5
Schedule
4.5
Cost
4.0
Willing to Refer
4.5

"Within the project guidelines and deliverables they excelled, came up with suggestions and were proactive."

Aug 31, 2017
Former CEO, Industry Index
Gayle Meyers
Verified
  • Advertising & marketing
  • New York City, New York
  • Phone Interview
  • Verified

4xxi acted as the engineering team, building an online platform from the ground up. They provided frontend and backend development and API integration. The platform grew from zero users to over 5,000 users. 

Web Dev for Health & Wellness Sharing Platform

  • Web Development
  • $50,000 to $199,999
  • July 2016 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"They deliver on every aspect they say they are going to.”

Aug 28, 2017
Founder, Nutmeg Asprin
Mara Landis
Verified
  • Other industries
  • New York City, New York
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi built an AWS and Digital Ocean website, and are currently working on the redesign. They provided feedback to help develop a rewards functionality and encourage a back-to-basics approach for improved UI.

Showing 1-10 of 13 Reviews

Locations (1)

54 Leyborne Park, Richmond LondonEngland TW9 3HA

41 - 49

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