Companies · category

Top IT Service Providers for JavaScript in the UK

8 IT service providers ranked by rating, review volume and listing quality.

JavaScript spans more ground than any other language on this list. It runs in every browser, on servers through Node, and inside mobile and desktop applications, so a firm listing it may be doing front-end interface work, back-end services, or both.

The useful clarification is which part of the stack, and with what. Front-end work is dominated by a handful of frameworks and the choice affects hiring for years afterwards. Back-end JavaScript competes with other server languages and is chosen for good reasons and bad ones. Ask why they would pick it for your project specifically — a clear answer indicates a team choosing tools, and a vague one indicates a team using whatever they already know.

Want your company here?

Between them, the 8 IT service providers on this page cover web design (7), mobile app development (5), PHP (5) and android (5). 8 of them have written a profile you can read before you get in touch.

We list more than 450 IT service providers in the UK listed for JavaScript development. The order comes from what each firm publishes and what has been verified about it, never from payment — at the top right now: Zepto Systems ltd, Marzee Labs and Webcurl LTD.

Before you shortlist, check

Which frameworks they use, and why for your project
Automated tests and code review as standard
Performance and accessibility targets agreed up front
How dependencies are kept up to date after launch

Filter by fitbudget, engagement, size and more

Listings marked Sponsored are promoted by TrustList. They are scored like every other listing and keep the position they earn.

Zepto Systems ltd
Sponsored
Mobile App Development · Custom Software Development · Web Development · Also in London and Islamabad
We are an IT service company providing full-scale Software Development, Bespoke Solutions, Cyber Security, Managed Project Development and Remote Developers to our clients…
Write a review
CaJSoft
Mobile App Development · Custom Software Development · Web Development
CaJSoft Ltd is a small web and software development company in Glasgow, Scotland.
Write a review
SwarmOnline Ltd
Mobile App Development · Web Development · UI/UX Design
SwarmOnline Ltd is a software developer based in Scotland that builds bespoke cloud and mobile applications.
Write a review
Toru Digital
Mobile App Development · Web Development · Web Design
Discovery, UX/UI Design, Branding, Consultancy, Web Development, Apps, Integrations, Cloud, Analytics, SEO, Support and Maintenance, KPI Optimisation.
Write a review
DataMatters Ltd.
Web Development · Web Design · Software Development
DataMatters Ltd. is a software company that provides MultiValue and Pick application software and consulting.
Write a review
Logic Room
Web Development · Web Design · UI/UX Design
Logic Room is a UK consultancy that works on JavaScript and TypeScript applications. Pete Heard started it in 2017.
Write a review
didge.io
Web Development · Web Design · UI/UX Design
didge.io is a small digital studio that designs, engineers and delivers digital products and transformation projects.
Write a review
RS
Red Sequence
Mobile App Development · Web Development · Web Design
Red Sequence is a software firm specialising in Azure, .NET, full-stack JavaScript and related web technologies.
Write a review

For vendors

Want to see your company here?

The order is earned on evidence: client reviews, vetting, awards and the facts a business states on its own website, which we read and date. Nobody can pay to move up. Add reviews or verified facts to your free profile to move up at the next edition; there are two ways to stand out now, and each one says what it is.

Not on TrustList yet? Add your company or claim its listing, free.

Get vetted

Free

We check your registration, your website and your clients
Approved listings show the Verified badge here and on their profile
It earns a rank number and counts towards the TrustList Score; renewed yearly

Apply for vetting How vetting works

Sponsor the JavaScript ranking

Paid · always labelled

A Sponsored card above the JavaScript ranked list
Marked Sponsored, and it never changes the order
Booked by the month; cancel any time

Book a spot See prices

How is this ranking worked out?

The order comes from what each firm publishes and what has been verified about it, and never from payment:

Profile completeness: the details a buyer needs to judge a firm — what it does, who it serves, how it prices, who it has worked for
Earned trust: verification, awards and the other checks a firm has actually passed
Client reviews, where they exist: the rating is smoothed, so one five-star review cannot outrank a firm with a hundred good ones, and volume counts with diminishing returns

Client reviews are still rare across this catalogue, so on most lists today the order is set by the first two. A firm near the top is the best-documented and best-verified one we hold, which is not the same claim as the best one to hire. Use the list to build a shortlist, then check the firms yourself.

Sponsored listings are labelled and shown apart from this list. How rankings work

Only firms whose profile names the UK are counted here, so a firm that lists a town but no country is not yet included.

Where else can I look?

The same list elsewhere: USA (762) · India (392) · Germany (214) · Ukraine (145).

Other specialisms in the UK: UI/UX design (941) · e-commerce (854) · Android app development (812) · iOS app development (800) · WordPress (752).

Every IT service provider in the UK: the full list.

Every category in the UK: the UK country page.

Other services in the UK

Same subject

More it service providers rankings

Every other way we rank it service providers, by what they do and where they are.

All 216 rankings

Articles

More categories

Jump to another ranked category.

All categories

Keep exploring

More on TrustList

Everything here links back to the same verified catalogue. Pick your next stop.

Top IT Service Providers for JavaScript in the UK

Zepto Systems ltd

CaJSoft

SwarmOnline Ltd

Toru Digital

DataMatters Ltd.

Logic Room

didge.io

Red Sequence