Looking for a top JavaScript developer in London?

If you're hiring a JavaScript developer to help you build or update a website that's responsive and interactive, consider the pros and cons of JavaScript as a programming language. Advantages include its speed because it's executed on the client-side; reduction in server load; and diverse functionality. Disadvantages to consider include security such as bugs on the client-side.

To assist you in your search for a partner, we’ve compiled this list of the top JavaScript development agencies in London. Browse descriptions, feedback, and awards to find which can best suit your company’s needs. If you need more support, tell us about your project, and we'll match you with recommended companies.

List of the Best London JavaScript Developers

  • 1
    $50,000+
    50 - 249 Employees
    London United Kingdom

    Tivix is a digital product development and design company headquartered in San Francisco, with offices across the US, UK, and Europe. Founded in 2008, they have over 90 employees who serve startup, midmarket, and enterprise clients across diverse industries such as FinTech, health care, manufacturing, government, and nonprofit. Tivix reduces engineering risk for clients by offering rapid time-to-market while delivering standards-based code that can be transitioned to an internal team at any time. Their focus is building both internal and consumer-facing digital products that drive business growth. Services include product management, UX/UI design, full-stack software engineering, and DevOps

    Clients
    Zoetis
    Apple
    Tesla
    UNICEF
    Industries
    Notable Project

    Tivix worked with an intergovernmental military alliance to rebuild a mission-critical software system. If and when submarines in international waters come into distress, the organization plans and coordinates the rescue effort of such submarines. Tivix was given complex system requirements and asked to come up with an effective design and solution that would replace a decades-old system. The client was incredibly impressed at every stage of the engagement, with Tivix delivering detailed systems and user-experience design, followed by robust development and operationalization of the system internationally. 

    Every single milestone has been met exactly on time. The company has met every requirement, both in terms of time as well as quality.” Maritime Service Owner, Intergovernmental Military Alliance

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  • 2
    $25,000+
    1,000 - 9,999 Employees
    London United Kingdom

    Headquartered in New York, iTechArt is a custom software development company with additional offices in Marietta, Ga. and Iselin, N.J. Since 2002, iTechArt has helped startups and fast-growing tech companies fill in their talent gap and create robust web and mobile solutions that users love. To date, iTechArt’s talent pool includes 1600+ engineers with experience in all of the latest technologies.

    Clients
    ClassPass
    Forex.com
    Merkle
    ZEFR
    Industries
    Notable Project

    iTechArt Group is assisting with the development of a content management software for video advertisements. The team is building the system to accommodate multiple social media platforms like YouTube and Facebook.

    “The engagement has been very successful overall thus far. The work we've been able to quickly launch wouldn't have been possible without iTechArt's help. In addition to the quality of their code, they've also integrated extremely well into our team, adapting to our internal processes relatively seamlessly.” – Founder & CTO, Software Consulting Agency

  • 3
    $50,000+
    250 - 999 Employees
    London United Kingdom

    DCSL GuideSmiths is a bespoke software development company headquartered in Farnborough, England with additional engineering centers in London, Manchester, England, and Madrid, Spain. Across international locations, they have a team of more than 250 individuals providing custom software, mobile application, and web development services to a diverse clientele. They support established businesses, nonprofits, government organizations, and startups

    Clients
    Mitsubishi
    Hospify
    Skanska
    Water Aid
    Notable Project

    DCSL GuideSmiths redeveloped the recruitment software system of a construction firm. After laying out their requirements, DCSL GuideSmiths designed, tested, and delivered on the system. The client was pleased with the project and felt that DCSL GuideSmiths' skills made the collaboration extremely easy. 

    "We were able to see straightaway how the system would look and work. That’s another reason it went so smoothly." – Manager, Support Department, Construction Firm

  • 4
    $25,000+
    10 - 49 Employees
    Sarratt United Kingdom

    Clock Limited is a digital design and build company. Founded in 1997, the company is headquartered in Kings Langley, United Kingdom. They have a team of around 35 employees who focus on custom software, web, and mobile app development.

    Clients
    International Tennis Federation
    Wall Street Journal
    Leicester Tigers
    The Sun
    Industries
    Notable Project

    Clock Limited redesigned a website for a news and media outlet. The team also built a custom CMS for the client. The site forms the foundation of the internal team's business.

    "The CMS is fantastic and they have been very receptive to our ideas, no matter how big or small." – Site Editor, News Outlet

  • 5
    $10,000+
    50 - 249 Employees
    London United Kingdom

    Propeller is a web design and development company that was founded in 2000. Headquartered in London, with another office in New York, they have a team of over 55. They specialize in e-commerce development, email marketing, web design, and SEO or clients in the hospitality, leisure, consumer products, and retail industries.

    Clients
    Hippo Inns
    JW Lees
    KOIBIRD
    RXBAR
    Industries
    Notable Project

    Propeller developed and designed a creative website for a photography studio. The team also performed digital marketing services, crafting keywords. SEO campaigns improved search results and mobile usage.

    "Propeller created a platform that represents me, my taste and artistic level."– Founder, Photography Studio

  • 6
    $50,000+
    50 - 249 Employees
    Hertford United Kingdom

    Zoocha is a web development firm founded in 2009 and headquartered in Hertford, in the U.K. The firm has other locations in Valencia, Spain; Balneário Camboriú, Brazil; and New York, N.Y. Zoocha has about 30 employees. 

    Clients
    UNICEF
    British Tourist Authority
    Clarion Events
    Engerati
    Industries
    Notable Project

    Zoocha created a web application for a UK oil and gas energy network. Using Drupal extensions and PHP scripting, Zoocha made an interactive platform for tracking and storing information. The client was impressed with Zoocha's work.

    "The refresh that we did with Zoocha Ltd has increased business value by three times, and in some areas, it’s about six times. We haven’t had any bugs or crashes." - CEO, UK Energy Service Firm

  • 7
    $10,000+
    10 - 49 Employees
    london United Kingdom

    Thought&Function is a digital agency founded in London in 2017 with no more than 10 members. They are experts in web development, mobile app development, and UX/UI design solutions for clients in the industries of financial services, education, and health care.

    Clients
    DoctorLink
    AllPlants
    ProperCorn
    Industries
    Notable Project

    Thought&Function developed an app for a personal finance company. The app was built entirely from scratch using React Native for both Android and iOS platforms. The app was released earlier than scheduled.

    “For me, what sets them apart is the relationship.” - Founder, Personal Finance Company

  • 8
    $75,000+
    50 - 249 Employees
    London United Kingdom

    With a team of 50+, Fueled specializes in creating mobile apps and websites. The New York-based app development company aims to create easy-to-use and attractive products for customers, whether they are big or small brands.

    Clients
    Rite Aid
    Sunnycomb
    QuizUp
    Verizon
    Industries
    Notable Project

    Fueled designed a bidding-style app for a company that deals with nightlife reservations. They built the app from scratch, taking into consideration what the company wanted, as well as giving advice. The app had a lot of functions, such as a list of venues, submission options, and tools that allowed notifications to be sent from venues.

    “They’re incredibly efficient in the work that they do and know what they're doing in design, coding, and executing their ideas. They have a great understanding of what's current and get things done very quickly compared to others.” – Founder, Mobile App

  • 9
    $100,000+
    50 - 249 Employees
    London United Kingdom

    Myplanet is a software studio headquartered in Toronto, Ontario, with additional offices in Vancouver, British Columbia, and Chicago, Ill. Founded in 2009, Myplanet's team of around 90 specializes in web development, web design, and e-commerce development, primarily for midmarket and enterprise clients in financial services and media.  

    Clients
    CenturyLink
    DigitalOcean
    Google
    Dow Jones
    Industries
    Notable Project

    A cloud platform developer hired Myplanet for assistance with digital strategy, information architecture, and user experience. The client's goal was to rebrand and reposition its digital presence as it moved away from providing hardware to providing cloud services. The client appreciated Myplanet's "customer-centric" approach to project management.

    "From day one to January 2015, we experienced a 300% increase in site traffic and 200% increase in leads coming from the web. Our bounce rate went down and our net promoter score went up." - Chief Marketing Officer & SVP of Business Operations, Cloud Platform Developer 

  • 10
    $5,000+
    50 - 249 Employees
    Northwood United Kingdom

    CMARIX is a technology outsourcing company based in Gujarat, India. Founded in 2009, the team of 115+ employees offers a focused specialty in web development, custom software development, and mobile app development. CMARIX primarily works in partnership with small businesses and midmarket clients.

    Clients
    CapitalOne
    Checkin
    Schneider Electric
    Swissmade
    Industries
    Notable Project

    CMARIX partnered with this VR gaming company to create a web app designed to communicate with VR arcades. Ideally, the product will show an aggregated list that drives web traffic towards these virtual venues. Using a PHP framework, CMARIX also integrated Stripe APIs, payment processing with Apple and Android. After completion, the user tests were successful and CMARIX helped set up Google Analytics.

    “We had a short timeline for this project, but CMARIX still delivered our product on budget.” –Product Manager, VR Gaming Company

  • 11
    $10,000+
    10 - 49 Employees
    London United Kingdom

    Catch is a digital experience agency founded in 2007. Based in London, United Kingdom, they also have an office in Madrid, Spain, and a team of over 30 employees. They specialize in web development, UX/UI design, and content marketing. 

    Clients
    Worldpay
    SES
    Thomas Cook Airlines
    Notable Project

    Catch helped an international conservation charity with multiple projects. First, they rebuilt a Drupal E-commerce website and built the CMS for the organization. In addition, the team manages the integration with ticketing and the CRM. Finally, they also worked on developing two applications. The company's website work resulted in increases in the number of users on the site and views.  

    "We’ve seen a positive impact on the site and how people have used it. We’ve had increases in users, conversion rates, page views, and so on." – Head of Digital Services, International Conservation Charity 

  • 12
    $10,000+
    50 - 249 Employees
    London United Kingdom

    CTI Digital is a full-service digital agency from Manchester, UK with other offices in London and Stockport, UK. The agency was established in 2003 and now has a team of 68 that works on web development, e-commerce development, mobile app development, and UX/UI design.

    Clients
    McGraw-Hill Education
    Mercuri International
    Royal Navy
    Manchester Central
    Industries
    Notable Project

    A government contractor previously had a website that was managed by one company and whose servers were hosted by another. They chose to consolidate all their website work at CTI Digital, who now hosts their servers, provides Drupal development, and updates the website and CRM.

    "The support is really great. The team that deals with support is absolutely brilliant...We have a very good two-way working relationship." — Project Manager, Government Contractor

  • 13
    Undisclosed
    10 - 49 Employees
    Soho United Kingdom

    IdeaWork Studios is a full-service advertising, development, and design agency founded in 1999. Headquartered in New York City, the company also has offices in Santa Barbara, CA and Las Vegas, NV. The team of more than 20 employees offers branding, web design, web development, and other marketing and design services such as logo and packaging design and email marketing.

    Clients
    Hard Rock Cafe
    Caesar's Entertainment
    Yahoo!
    MGM Resorts
    Industries
    Notable Project

    After a wellness resort was acquired by another company, it needed to rebrand and hired IdeaWork Studios. The project included creating a new name and logo for the resort, updating its website to reflect the new branding, and launching an advertising campaign.

    "The level of creativity they showed for a complete rebranding was impressive. We needed to take the resort in a completely different direction, and they did it very quickly. It was impressive what they understood about the brand and what they put forward from a presentation standpoint." – Director of Sales and Marketing, Wellness Resort

  • 14
    $5,000+
    2 - 9 Employees
    London United Kingdom

    Digital product studio Series Eight is located in London. Since the company's founding in 2014, their small team of five has specialized in web design and development, UX/UI design, branding, and more with primarily small and mid-market businesses.

    Clients
    Kuoni
    Cardconnect
    Trōv
    Flowhub
    Industries
    Notable Project

    A skiing electronics company hired Series Eight for a complete website redesign. They wanted to optimize user experience and increase sales. Since the website's launch, conversion rates have increased. 

    "They have been absolutely excellent. Despite both our team and their team being remote, we’ve managed to maintain outstanding communication."–CCO, Skiing Electronics Company 

  • 15
    $1,000+
    10 - 49 Employees
    London United Kingdom

    Zesty is a full-service digital agency based in Dublin, Ireland, with additional offices in Belfast, Northern Ireland and London, England. Zesty was founded in 1996 and has 37 employees. Services offered by Zesty include web development, web design, and digital strategy.

    Clients
    Ulster Orchestra
    talkSPORT
    EY Financial Services
    Industries
    Notable Project

    Zesty was responsible for web design and development for a tourism board. The project included developing a brand new website with an engaging design, along with transferring pre-existing data from the old platform to the new one. The client reports that the new site has led to double-digit growth in page views.

    "I was impressed by their ability to relate to us, understand our needs, and work towards the bigger picture." - CEO, Tourism Board

  • 16
    $25,000+
    10 - 49 Employees
    London United Kingdom

    Theodo UK, founded in 2015, is a consultancy and digital development agency headquartered in London with an additional location in Paris. With a team of over 30 employees, they mainly provide mobile app development, web development, and custom software development services.
     

    Clients
    Admiral
    Cleo.
    BNP Paribas
    Voodoo
    Industries
    Notable Project

    Theodo UK developed the platform for an online marketplace after the previous developer proved unsatisfactory. The team took wire frames and a prototype provided by the client to build a minimum viable product, using AWS, React, Python, and Django for the framework. The client spoke highly of the engagement.

    “They’re extremely knowledgeable and work closely with us to make sure we know what’s going on. Their team is phenomenal and have both dev and interpersonal skills.” — Executive, Digital Office Marketplace

  • 17
    $5,000+
    10 - 49 Employees
    London United Kingdom

    White Label Coders is a software house founded in 2011 and located in Gliwice, Poland. They employ 15 industry professionals specializing in Magento e-commerce and custom business web application development. They work primarily with international companies, providing innovative solutions for WordPress, e-commerce, and custom software.

    Clients
    HomeKoncept
    DrOmnibus
    Adexbud
    Industries
    Notable Project

    White Label Coders developed and managed a custom software solution to manage all business operations for a computer hardware company. They worked quickly and effectively, implementing a job management system, inventory management, a CRM, and integration with VoIP. The system is the functional foundation of the business, integral to all daily operations.

    “This system runs the entire backend of our company. Without it, we wouldn't be able to get done what we need to get done. They’re also a great team to work with. They've always delivered exactly what I needed.” – CEO, Computer Hardware Company

  • 18
    $10,000+
    10 - 49 Employees
    London United Kingdom

    Solar Digital is a development-focused digital agency based in Odessa, Ukraine. Founded in 2016, Solar Digital has a team of 28 employees. They provide branding, UI/UX design, web development, and mobile app development services to a diverse and global client base.

    Clients
    Stark Research
    Kassir 24
    Olir
    Klazz
    Industries
    Notable Project

    A shipping company on the Black Sea hired Solar Digital to design and build a CRM platform. The product needed to be able to handle a considerable flow of data from large cargo operations, including bulk shipping that does not use containers. Solar Digital created a system for tracking and managing shipments and port facilities, which automated many steps in the client's process.

    "Our work and our financial returns have increased 3 times since 2014." –Commercial Director, Ukrainian Shipping Firm

  • 19
    $25,000+
    50 - 249 Employees
    London United Kingdom

    Box UK is an enterprise software development company based in Cardiff, UK, with an office in London. The company, founded in 1998, has more than 50 employees who provide, among others, custom software development, web development, and enterprise app modernization services to various businesses. 

    Clients
    OKdo.com
    RS Components
    ateb
    BMJ Best Practice
    Industries
    Notable Project

    Box UK was hired by an Employee Benefits Service to oversee and advise on the Service's new e-commerce platform. But their service was expanded to include the development of the platform, rewriting some parts in Symfony from the original CakePHP. The client was so satisfied with the work that Box UK is still onboard to supply new features on the platform as needed. 

    "Box UK has a very modern, agile approach and is good at looking at new methods of working." - Project Manager, Employee Benefits Service 

  • 20
    $25,000+
    10 - 49 Employees
    London United Kingdom

    Purr Digital is a software development agency that has been offering web development, mobile app development, and custom software development to their small business and mid-market clients in the hospitality, arts and entertainment, and consumer products and services industries since 2013. Their 50 employees are based out of their London and Birmingham, UK offices. 

    Clients
    Adplan
    A Team Insight
    Maison de Fleurs
    Industries
    Notable Project

    An internet services company partnered with Purr Digital for a technical solution and software platform for their mobile app. They provided the client with design, software development, and backend support for the mobile application. This resulted in a 35% conversion in regions that received 400 transactions the first two weeks.

    ”Their team has made constructive suggestions for features that we didn’t even think about, which has been quite crucial actually. They did a fantastic job. No one on my team is highly technical and Purr Digital guided us through the whole process.” — Director, Internet Services Company

  • 21
    $25,000+
    50 - 249 Employees
    London United Kingdom

    Mobile app development company Tapptitude has offices in Romania, the US, and London. The team of 40+ employees specializes in iOS and Android app development and offers UX/UI design, IT strategy consulting, and web development. Founded in 2013, Tapptitude mainly works with small businesses and startups in the real estate, automotive, and arts and entertainment industries.

    Clients
    Honda
    Vias Wine
    SmartDreamers
    Dine Market
    Industries
    Notable Project

    Tapptitude developed an app prototype for a food ordering company. They executed the food ordering company’s vision perfectly and were retained to develop the full product. Some app features Tapptitude developed included platform signup, payment systems, and restaurant menu integration.

    “The proof that I’ve been happy with Tapptitude is that we’ve continued working long-term, even though I’ve had the option to use in-house developers. I felt that the communication was great and, most importantly, the quality Tapptitude provides is amazing, as is the communication.” – CEO, Food Ordering App

  • 22
    $5,000+
    10 - 49 Employees
    London United Kingdom

    Marzee Labs is a web development company that has been offering web design, web development, ad e-commerce development services to their clients since 2013. Their 10 employees are based out of their Porto, Barcelona, London, and Setúbal, Portugal offices.

    Clients
    ARTE GEIE
    Branded Entertainment - BEN Group
    , Portuguese Catholic University
    Industries
    Notable Project

    Marzee Labs recently worked on multiple web designs for a TV station. They provided Drupal development and worked on the main websites and the project was successful.

    “Their ability to always find new talents and recruit some good developers impressed me.” – Project Manager, TV Station

  • 23
    $5,000+
    10 - 49 Employees
    London United Kingdom

    Ester Digital is a web design agency based in Tallinn, Estonia. Founded in 2015, the team of 7 specializes in web design, graphic design, and logos. They work mostly with small business clients, and primarily work within the advertising and marketing, information technology, and business services industries.

    Clients
    Tappi
    Adzoola
    Terve
    Clinic 77
    Industries
    Notable Project

    Ester Digital worked with a tech startup to redesign their logo and develop its company website. The client was amazed by the graphic design skills of Ester Digital’s team and started to use the new logo for all its marketing.

    “We are proud of how the new logo represents us. We currently use the logo and guidelines to create new marketing materials.” – Head of Marketing, Tech Startup

  • 24
    $25,000+
    50 - 249 Employees
    London United Kingdom

    Located in Ahmedabad, India with additional offices in the US and UK, Innovify has been delivering high quality solutions since 2011. Although the team of nearly 130 specializes in mobile app development, they also engage in growth hacking, consulting, and UX design.

    Clients
    Microsoft
    BBC
    The Wall Street Journal
    HSBC
    Industries
    Notable Project

    One of Innovify’s clients, an on-demand delivery platform, wanted to streamline how merchants and businesses placed orders and how they assigned drivers. Innovify developed an Android app and website and helped with marketing and strategy.

    “I have worked with a couple of these companies before, but they haven’t been as process-oriented as Innovify. They have good processes in place and everything was good for me.” – Founder, Logistics Company

  • 25
    $5,000+
    2 - 9 Employees
    London United Kingdom

    Appetite Creative Solutions is a creative digital marketing agency in London, England – with offices in Madrid and Dubai, too. Established in 2015, Appetite Creative Solutions has a team of 25 employees. They offer logo, web design, games development, and social media marketing services.

    Clients
    Starbucks
    Bacardi
    Coca Cola
    Tetra Pak
    Industries
    Notable Project

    Appetite Creative Solutions developed a marketing campaign for a digital sales company to increase exposure. They created mockups, high-impact ads, and eye-catching marketing games. The clients' were pleased with the innovative designs.

    "They’re hands-on, accommodating, and creative." – Marketing & Advertising Professional, Digital Sales Company

  • 26
    $10,000+
    10 - 49 Employees
    London United Kingdom

    Tech Alchemy was founded in 2016 and has two locations in London. Their team of nearly ten employees provides web development, mobile app development, and UX/UI design services for small businesses.

    Clients
    TOAD
    Copofi
    Tona
    Triptalk
    Industries
    Notable Project

    Tech Alchemy developed a new UX for an existing cross-platform mobile app prototype for a health startup using Flutter. The team went through three sprints to deliver the product. Their work helped the client simplify a complex app.

    "We were able to drastically simplify a complex app and release it to our corporate clients." –CTO & CPO, Health Startup

  • 27
    $25,000+
    50 - 249 Employees
    Sutton United Kingdom

    Geeks is a software development company in London. Founded in 2007, Geeks' team of 85 specializes in custom software development, web development, and mobile app development, primarily for midmarket clients in media and govenment.

    Clients
    easyJet
    Aesseal
    Houses of Parliament
    BBC
    Industries
    Notable Project

    An online history encyclopedia hired Geeks to build a web app for extracting content from other websites. The client's key challenge was ensuring that the web app could handle a high volume of data. Geeks developed custom software featuring a user-friendly frontend and a backend capable of extracting significant amounts of data. Finally, Geeks created a JavaScript library that the client can sell to other businesses. The client appreciated Geeks' creativity and innovation.

    "Our visualization engine can generally handle ten times more data and the average JavaScript library. We’ve had no problems with the stability of their code. The server has always been perfect." - Co-Founder, Online History Encyclopedia

  • 28
    $10,000+
    10 - 49 Employees
    London United Kingdom

    Made Tech is a London-based software services provider that was founded in 2010. The company employs a team of 33 that provides e-commerce development, web development, custom software development, and conversion optimization services to mid-size and small businesses.

    Clients
    Rocket Internet
    Finery London
    Byron Hamburgers
    On Running
    Industries
    Notable Project

    A fashion retailer was trying to create a website from scratch for the first team and needed to outsource the development. Made Tech worked from wireframes and graphics to develop the backend of a customized e-commerce website.

    "We’ve got a best-in-class conversion rate across multiple devices, so I think that’s testament to the fact the site works well...From a project management perspective, they’ve been very good. It’s been a very collaborative effort." — Founder & CEO, Fashion Retailer

  • 29
    $5,000+
    10 - 49 Employees
    London United Kingdom

    DEGO is a web services development agency based in Riga, Latvia with an additional office in Moscow. Founded in 2005, DEGO has fewer than ten employees, and provides e-commerce development, UX/UI design, web development, and mobile app development capabilities to small and midmarket businesses.

    Clients
    Jaguar XE
    Ina Vokich
    Bio2you
    Aspazija Museum
    Industries
    Notable Project

    DEGO worked with a spirits supplier to assist with its brand activation campaign, which included site development, promotional video production, and the creation of a VR app for iOS. They redesigned the site's UI, filmed a promotional video, and worked with Google Cardboard for the VR app; DEGO made sure to implement offline capabilities in the mobile app, and included an intuitive interface for staff and users alike to use without directions.

    "We appreciated DEGO’s quick turnaround." - Marketing Manager, Spirits Supplier

  • 30
    $10,000+
    2 - 9 Employees
    London United Kingdom

    Browser London is a digital product agency based in London, United Kingdom. This company has 11 employees and was founded in 2008. Services offered by Browser London include UI/UX design, web design, and custom software development for companies of all sizes.

    Clients
    Gov.uk
    Mayor of London
    Lightning API
    Industries
    Notable Project

    Browser London provides ongoing development work and UX design with a creative agency. Their work involves JavaScript coding, UI/UX design, and additional aspects of technical development.

    "They’re a knowledgeable team. Using their modern, forward-thinking outlook, they delivered a beautiful product. They’re experienced and dedicated, allowing them to ensure that the project is spot-on." Strategy Director, Creative Agency

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Based on your budget, timeline, and specifications we can help you build a shortlist of companies that perfectly matches your project needs. Schedule a free consultation with a Manifest Analyst.

TELL US ABOUT YOUR PROJECT