The best SEO link building agencies in 2026
Comparison of 8 SEO link building companies.
A guide to the top SEO link building agencies in 2026, comparing outreach expertise and digital PR capabilities to help you find the right organic growth partner.
Our SEO link building agency comparison guide
Link building is a major driving factor in organic rankings; quality matters more than quantity, with earned media (gained through genuine authority and trust) offering far more lasting value than paid placements.
In this guide, we review the top SEO link building agencies based on how they build authority through earned links - such as digital PR, expert commentary, and strategic outreach - versus paid methods like guest posting and niche edits.
Overview of the leading SEO link building agencies
We've summarised key information about the leading SEO link building agencies in 2026 in an easy-to-scan comparison table, helping you quickly identify the right partner.
Best SEO link building service offerings
We reviewed eight agencies, comparing the SEO link building services they offer.
The top 8 SEO link building agencies in 2026
1. Reboot Online
An award-winning search marketing agency that uses advanced link building techniques to secure genuine, high-authority earned links. Reboot is also a highly regarded digital PR agency, using data-driven digital PR and AiPR™ campaigns, expert outreach, and innovative hyper-relevancy projects to secure top-tier placements from reputable publications.
Location
Remote (UK)
Why they stand out as a leading SEO link building agency
- Multilingual digital PR specialists deliver global coverage across the UK, EU, APAC, and the Americas
- Over 48,000 backlinks for clients worldwide across competitive sectors
- Data-backed campaigns led by PhD-level analysts
- Free digital PR cost calculator offering transparent pricing
Awards in 2026
- Best Large SEO Agency - Global Search Awards 2025
- Best Use of Search (SEO): B2B (Large) - UK Search Awards 2025
Ideal for
Ambitious brands looking for a proven partner to help them dominate organic search and maximise ROI through data-driven strategies.
2. Hallam
Hallam is a full-service digital agency with offices in Nottingham and London. They offer SEO supported by integrated digital PR and content marketing strategies designed to attract high-quality backlinks from relevant publications. Their approach focuses on long-term authority growth through data-led campaigns and creative outreach.
Location
Nottingham (UK) and London (UK)
Why they stand out as a leading SEO link building agency
- Integrated digital PR and SEO teams delivering campaigns designed to earn editorial links
- Experience running authority-building campaigns for enterprise and B2B brands
- Data-led digital PR campaigns
Awards in 2026
- Best Large Agency - UK Agency Awards 2025
- Best Use of Search (B2B/PPC): Large - Global Search Awards 2025
Ideal for
B2B brands looking for a data-driven organic growth partner for long-term growth.
3. Seeker Digital
Seeker Digital is a Bristol-based agency known for successful manual outreach and content partnerships that generate natural, contextual links from high-authority domains.
Location
Bristol (UK)
Why they stand out as a leading SEO link building agency
- Proven track record of successful outreach
- Transparent reporting and clear campaign performance tracking
- Combines AI-powered efficiency with human creativity to create scalable processes
Awards in 2026
- N/A
Ideal for
Brands looking to maximise ROI through scalable organic search.
4. UK Linkology
UK Linkology focuses exclusively on link building, with a particular emphasis on quality and relevance. Their process combines manual outreach and contextual placements supported by SEO performance data.
Location
Derby (UK)
Why they stand out as a leading SEO link building agency
- Specialist focus on outreach-based link acquisition
- Emphasis on contextual placements and topical relevance
- Processes designed to deliver scalable and compliant link building
Awards in 2026
- N/A
Ideal for
Companies wanting high-authority, low-risk link profiles delivered quickly.
5. Seeders
Seeders is a cross-border marketing and SEO agency that bridges local and global link acquisition. Their multilingual link building and international outreach network make them a go-to for brands targeting multiple markets.
Location
Zwolle (NL), Antwerp (BE), Düsseldorf (DE), Barcelona (ES), Lyon (FR), Warsaw (PL), Shanghai (CN), Kigali (RW)
Why they stand out as a leading SEO link building agency
- Multilingual outreach teams capable of securing links across international markets
- Integration of digital PR, content marketing and link building
- Experienced in building global backlink profiles for growing brands
Awards in 2026
- Included in the Top 250 Growth Companies 2025 (Top 250 Groeibedrijven) list in the Netherlands
Ideal for
Brands of all sizes that want to focus specifically on international link building and company growth.
6. Eskimoz
Eskimoz is a European SEO and full-service digital agency specialising in organic growth strategies that include link building, digital PR, and content performance optimisation.
Location
London (UK), Paris (FR), Madrid (ES), Milan (ITA), and Düsseldorf (DE)
Why they stand out as a leading SEO link building agency
- Established presence across several European markets
- Integrated SEO and content campaigns designed to earn editorial links
- Experience supporting fast-growing eCommerce and digital brands
Awards in 2026
- Best Digital Acquisition (Gold) - Cas d’Or Awards 2026
Ideal for
Startups and DTC brands maximising revenue through organic search.
7. Reposition
Reposition delivers ethical, white-hat link building using tailored outreach to secure placements in authoritative and industry-relevant publications. Their campaigns focus on long-term authority rather than quick wins.
Location
London (UK)
Why they stand out as a leading SEO link building agency
- Manual outreach approach focused on editorial placements
- Strong emphasis on topical relevance and authority
- Experience delivering link building strategies for competitive industries
Awards in 2026
- N/A
Ideal for
Businesses focused on links in highly relevant, targeted publications.
8. Pearl Lemon
Pearl Lemon is a global agency offering end-to-end SEO link building services through digital PR, HARO link placements, and strategic partnerships. The team tailors each campaign to each client’s industry and growth stage.
Location
London (UK)
Why they stand out as a leading SEO link building agency
- Flexible link building strategies combining PR and outreach
- Experience supporting startups, SaaS companies and SMEs
- Integrated search marketing expertise across SEO, PPC and content
Awards in 2026
- N/A
Ideal for
SMEs and fast-growing startups that require agile link building and wider search marketing strategies.
Why link building matters in AI search
AI search - including AI Overviews (AIOs) and LLMs like ChatGPT, Claude, and Gemini - has changed the way people find information online. Gone are the days when we would type a query into Google, then simply choose from a list of relevant web pages. Today, AIOs appear on 21% of all keywords and 46% of search queries over seven words. That means users are presented with a fully formed answer before seeing any web pages. On top of this, an increasing number of users are turning straight to LLMs for their answers. If your business isn’t being mentioned, you risk becoming invisible to a growing audience.
Hiring a GEO agency helps you stay visible in the future of search. Generative Engine Optimisation (GEO) is the process of optimising your site to appear in AI-generated answers. Link building, particularly with an AiPR™ agency, is the best way to signal the authoritativeness and credibility of your site to AI platforms. As a result, they see you as a trustworthy site to pull information from.
Questions to ask your SEO link building agency
How do you ensure links are earned ethically and within Google's guidelines?
Reputable agencies focus on earning links through digital PR, expert commentary, and outreach rather than paid placements. This ensures links are placed because of genuine value and are compliant with search engine guidelines.
What types of publications or websites do you typically secure coverage from?
Quality link building targets authoritative websites with relevant content. This could be news publications, industry-related websites or trusted blogs.
How do your link building strategies tie in with technical SEO and content?
Link building works well alongside wider SEO strategies, like technical and on-page SEO. Find out if your prospective agency has the capabilities to manage this.
What metrics or KPIs do you use to measure the effectiveness of your link building campaigns?
Link building success is often measured by the number of links earned. But what does this actually mean for your business? A strong agency will report additional metrics, such as keyword ranking improvements and increases in organic traffic, as well as the impact on leads, sales, and revenue.
