London has one of the deepest pools of digital marketing talent in the world. Within a few Tube stops you can find global media networks, private equity backed performance groups, employee-owned independents and specialist search shops. That choice is useful, but it also makes shortlisting hard, because almost every agency now claims to cover SEO, paid media, social, data and AI search.
This list focuses on digital marketing agencies in London that run search and paid media as core, day-to-day services rather than add-ons. We checked each firm against its own website for a London office address, for SEO and paid media in its service line-up, and for verifiable work such as named case studies, awards or certifications. No company paid to appear, and the order reflects our view of strength and fit for typical London buyers.
If you are comparing specialists as well as integrated agencies, our London services hub links to related lists, including SEO, PPC and social media agencies in the capital.
London Digital Marketing Agencies At A Glance
Agency
London Base
Best For
Core Services
Brainlabs
Old Street, EC1Y
Data-led brands with large media budgets
Paid search, paid social, SEO, programmatic, retail media, data
Croud
Shoreditch, EC2A
International brands needing scale across markets
Media buying, paid search, paid social, creative, commerce feeds
Found
Hatton Garden, EC1N
Retail, hospitality and e-commerce brands
SEO, PPC, paid social, digital PR, data and AI
Impression
Borough, SE1
Mid-market and enterprise brands wanting integrated search
SEO, paid media, digital PR, social, CRO
ROAST
Soho, W1D
Brands wanting an award-winning independent
SEO, PPC, paid social, programmatic, data, web
Journey Further
Holborn, WC2B
Consumer brands focused on discovery and growth
Paid media, organic media, marketing science
Harvest Digital
Fitzrovia, W1T
Brands wanting an employee-owned media partner
Paid search, paid social, programmatic, DOOH, CTV, SEO
Semetrical
Old Street, EC1V
Data-heavy and multi-market organisations
SEO, GEO, paid media, analytics, content
Hallam
King’s Cross, N1C
B2B and complex-sale organisations
Paid media, organic and AI search, ABM, web, data
DEPT
Old Street, EC1Y
Enterprises combining marketing and technology
Brand and media, commerce, CX, tech and data, AI
Best Digital Marketing Agencies Options In London
1. Brainlabs — Independent Performance Agency With Experiment-Led Media
Brainlabs is an independent, founder-led performance agency whose London office sits in the White Collar Factory on Old Street, EC1Y. It runs a broad media and search line-up: paid search, paid social, programmatic and CTV, retail media, SEO, AI visibility, influencer marketing, performance creative and site experience work, supported by a data team that handles attribution, incrementality testing and marketing mix modelling.
The agency is known for its testing culture. Its site describes a “Test and Earn” approach and an internal knowledge base of more than 2,500 logged experiments that feeds its AI tooling. Brainlabs also says it publishes fully loaded rate cards upfront, which is useful for procurement teams that want pricing clarity before a pitch.
It suits retail and e-commerce, financial services, travel, consumer tech, B2B SaaS and healthcare brands with meaningful media spend and an appetite for measurement. Brainlabs holds ISO/IEC 27001 certification, and its site lists partnerships with Google, Microsoft, Meta, TikTok, LinkedIn and The Trade Desk.
2. Croud — Independent Media Agency With A Global On-Demand Network
Croud was founded in 2011 by Ben Knight and Luke Smith and has its London office in The Bard Building on Curtain Road, Shoreditch. It describes itself as an independent global media, creative and data agency, and it organises its work into four suites covering audience, creative, media and commerce, all run on its own CroudOS technology platform.
What sets Croud apart is its model. Alongside more than 600 in-house specialists, it draws on an on-demand network of around 2,900 freelance marketers, which it calls Croudies, to cover languages and markets. The agency says it works in 118 markets. Campaign named Croud Global Independent Media Agency of the Year 2025, and published case studies include a 55% rise in enquiries for workspace provider IWG.
Croud fits brands that sell across many countries and want one partner for media, feeds and creative testing. The wider Croud Group also includes social agency Born Social and luxury specialist Croud Luxe, which helps if you want related services under one roof.
3. Found — Hatton Garden Search And Media Agency With Its Own AI Visibility Platform
Found is a London-based digital marketing agency in the Johnson Building on Hatton Garden, with a second office in New York. It is part of Tomorrow Group, which also includes data and AI consultancy Braidr. The service menu is wide but tightly linked to search: technical, e-commerce and international SEO, PPC, paid social, programmatic, digital PR, content, CRO and analytics.
The agency positions itself as an “Everysearch” business and runs Luminr, its own AI-powered visibility platform for tracking how brands appear across search and AI answers. Found won Standout PPC Agency of the Year at the UK Digital Excellence Awards 2026, holds Google Premier Partner status and ISO 27001 certification, and reports a 40% year-on-year uplift in a Toolstation case study.
Client logos on its site include Toolstation, Puma, Peacocks, Ennismore and Clermont Hotel Group, so Found is a natural fit for retail, hospitality and multi-site brands that want search, paid media and PR planned together.
4. Impression — B Corp Certified Integrated Search And Performance Agency
Impression started as a small team in Nottingham and now has offices in Nottingham, London, Manchester and New York. Its London base is The Typewriter Building on Borough High Street, SE1. The agency has more than 120 staff and is a Certified B Corporation.
Services cover strategy, SEO, paid media, PR and social, media solutions and digital experience work. Impression has a strong awards record: its site shows Independent Agency of the Year and Integrated Agency of the Year badges for 2026, and it won Best UK SEO Campaign at the 2026 Global Search Awards. It also appears in The Drum’s Top 100 Indie Agencies for 2026.
Published case studies include work for Wizz Air, Norse Atlantic Airways, Tensar and Queensmith, and logos on its site include Specsavers, Clarins and Cancer Research UK. Impression suits organisations that want SEO, paid media and digital PR run by one accountable team with a robust reporting culture.
5. ROAST — Soho Independent Agency And Certified B Corp Founded In 2015
ROAST was founded in 2015 and runs from Frith Street in Soho, with further offices in Cape Town and New York. It is a Certified B Corporation with a score of 91.1 and holds Google Premier Partner status for 2026. The agency was named Independent Agency of the Year at the UK Agency Awards 2026.
The service line-up is genuinely full-funnel. Organic performance covers technical SEO, content, ASO, GEO and digital PR. Paid media spans PPC, paid social, programmatic, audio, out-of-home and TV. ROAST also offers data and measurement, web development, UX and CRO, plus a dedicated B2B practice. It has built its own tools, including ROASTWriter and ROASTPulse.
Clients and case studies on its site include Experian, Rightmove, Skyscanner, The Independent, AJ Bell, Hyperoptic and The National Lottery. ROAST reports a 93% client retention rate, which suggests it suits brands looking for a long-term partner rather than a project shop.
6. Journey Further — Performance Agency Built Around Search, Social And AI Discovery
Journey Further was set up in 2017 and has offices in Leeds, Manchester, London and New York. Its London office is at 88 Kingsway in Holborn. The agency groups its work into marketing science, organic media and paid media, presented together as a “Discovery System” for how customers now find brands across search, social and AI platforms.
The agency has grown quickly. Its timeline notes repeat appearances on Adweek’s Fastest Growing Agencies list and Campaign’s Global Performance Marketing Agency of the Year, plus the 2025 acquisition of influencer and talent agency Saulderson Media. It publishes a Brand Discovery Index based on a survey of 400 senior brand marketers in the UK and US, and has built its own tools such as Salient and a Relative Discovery Score.
Testimonials on its site come from Adobe, La Redoute, Sofa.com and Boots Hearingcare. Journey Further is a sound pick for consumer brands that want paid and organic teams working to a shared growth target.
7. Harvest Digital — Employee-Owned Independent Media Agency In Fitzrovia
Harvest Digital is an independent, employee-owned media agency based at 75 Newman Street in Fitzrovia. It describes itself as one of the largest independent media agencies in the UK and says it has managed more than £500m of media investment since launch.
The agency covers paid search, paid social, programmatic display, digital out-of-home, connected TV and retail media, alongside SEO, CRO, data and analytics and integrated strategy. Its own Receptivity model shapes how it plans media around when audiences are most open to a message. Harvest is a Google Premier Partner, and its site points out that it is not tied to the centralised buying policies of holding company networks.
One published example is a summer DOOH campaign for THE OUT that the agency says drove a 40% uplift in brand searches. Harvest suits brands that want joined-up planning across online and offline digital channels with the independence of an owner-run business.
8. Semetrical — Data-Led Search And Analytics Agency Founded In 2013
Semetrical was founded in 2013 and is based at 124 City Road, near Old Street. It combines digital marketing with a strong data and technology arm. Marketing services include SEO, generative engine optimisation, paid media, content marketing and AI consultancy, while the data team handles analytics implementation, insight and strategy, predictive analytics and analytics training.
The agency builds its own tools, including Tomo, a free robots.txt tool, Dexter for tracking published and updated articles, and Ogorki5 for automated technical checks. Featured case studies include improving paid search across 19 markets, and a testimonial from FDM credits Semetrical’s integrated international strategy with contributing to a record year.
Logos on its site include Stripe, Cloudflare, Ticketmaster, LexisNexis, Sotheby’s and The Spectator, a mix of publishers, tech firms and B2B brands. Semetrical is a good fit for organisations whose growth depends on solid tracking, technical search and data that leadership can trust.
9. Hallam — B Corp Digital Agency With A King’s Cross Office And B2B Depth
Hallam is a Certified B Corp digital agency with offices in Nottingham and at The Gridiron Building, 1 Pancras Square, King’s Cross. Its services are grouped into brand, reach, experience and data, covering creative campaigns, digital strategy, paid media, organic and AI search, account-based marketing, digital PR, content, web design and development, CRO and analytics.
The agency has a solid awards record, including a Global Search Awards 2024 win and Marketing Week Campaign of the Year 2024, and it holds a Drum Recommends score of 8.9. It also runs Better B2B, an online community for B2B marketers, and uses its own Elements diagnostic framework at the start of engagements.
Case studies and testimonials come from Lattice, Workbooks, Hitachi Solutions, Infodesk and Holcim UK. Hallam stands out for B2B companies that need paid media, search and ABM tied to pipeline, though its integrated model also works for consumer brands that want web and marketing under one team.
10. DEPT — Global Marketing And Technology Group With A City Road Office
DEPT is a global marketing and technology company with its London office in the Featherstone Building at 66 City Road, EC1Y. Its site lists 36 offices worldwide, 19 of them in Europe, and shows B Corp and Climate Label logos.
Rather than a pure media agency, DEPT combines brand and media work with commerce, customer experience, technology and data, plus AI transformation. That mix suits organisations where digital marketing depends on platform work, such as replatforming a commerce site, building data pipelines or rolling out marketing automation. Its listed technology partners include Adobe, Google, Optimizely, Salesforce and Shopify.
DEPT focuses on banking and financial services, consumer goods, health, retail and commerce, and tech, media and telecoms. It is best suited to larger brands that want marketing, engineering and data specialists in a single partner, rather than smaller companies looking for a lean campaign team.
How To Choose A Digital Marketing Agency In London
Do You Need An Integrated Agency Or A Specialist?
Integrated agencies such as ROAST, Impression and Found can run SEO, paid media and PR as one plan, which reduces hand-offs and conflicting reporting. Specialists can go deeper in one channel. If most of your growth comes from one channel, a specialist may serve you better; if you need several channels to work together, start with the integrated firms above.
What Proof Should You Ask For?
Ask for case studies in your sector with named results, references from current clients, and examples of how the agency reports. Certifications such as Google Premier Partner, ISO 27001 for data security, or B Corp status are useful signals, but they do not replace evidence of commercial results such as revenue, leads or return on ad spend.
How Are London Agencies Usually Priced?
Most London agencies charge a monthly retainer for ongoing work, a project fee for audits or migrations, or a percentage of media spend for paid campaigns. Pricing depends heavily on scope and media budget, so ask for a rate card or a breakdown by role and hours. Brainlabs, for example, says it shares fully loaded rate cards upfront. Our guide to how much SEO costs covers typical search fees in more detail.
Does Being In London Matter?
For many buyers, yes. A London office makes in-person workshops, quarterly reviews and creative sessions easier, and London teams tend to know the UK media landscape well. If you mainly need execution and are comfortable with remote working, the strongest firms on this list all run hybrid teams across several offices.
How Should You Run The Selection Process?
Shortlist three or four agencies, share a clear brief with goals, budget and timelines, and ask each for a short strategic response rather than a full free pitch. Meet the people who would actually run your account, and agree measurement and reporting before you sign. Our guide on how to choose a digital marketing agency in London walks through each step.
The best digital marketing agencies in London combine channel expertise with clear measurement. Brainlabs and Croud bring scale and testing discipline for large media budgets, ROAST, Impression and Found offer award-winning integrated search and media, and Journey Further, Harvest Digital, Semetrical, Hallam and DEPT each bring a distinct strength, from employee ownership to data engineering and B2B depth.
Start with your growth goal and budget, then shortlist the two or three firms whose strengths match. For related specialists across the capital, see the London and UK lists above.
