Company lists · Data refreshed September 2026
Top 25 Cross-border SEO agencies based in Spain
RevenueBase identified 364 cross-border SEO agencies headquartered in Spain as of September 2026 and tracks 1,699 professional contacts across them, including 305 with verified work emails. Barcelona is the largest hub.
This list covers cross-border SEO agencies headquartered in Spain, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 27, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest cross-border SEO agencies based in Spain
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 108 contacts → | ||||
Partial evidence “En nuestra agencia SEO en Barcelona somos unos apasionados del posicionamiento web.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 89 contacts → | ||||
Indirect evidence “ATLS is the strategic partner that drives business expansion into international markets, combining advanced technology, content localization, and multilingual digital marketing.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 85 contacts → | ||||
Indirect evidence “Royal Comunicación es una empresa dedicada al Marketing online teniendo como fin principal optimizar y rentabilizar los recursos de las empresas en la red.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 83 contacts → | ||||
Indirect evidence “SÚMATE es una agencia de marketing online orientada a resultados medibles.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 71 contacts → | ||||
Indirect evidence “Since 2012, at Interamplify, we have become strategic partners for brands and companies seeking to expand digitally on a global scale.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 38 contacts → | ||||
Indirect evidence “Esta empresa se creó para dar respuesta a una necesidad cada vez más demandada: el posicionamiento web.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 38 contacts → | ||||
Indirect evidence “Keyweo is a digital marketing agency founded in 2018 and based in Barcelona.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 31 contacts → | ||||
Indirect evidence “Since 2001, we've been boosting the online discoverability of leading international companies and media outlets.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 23 contacts → | ||||
Partial evidence “Convertix is an International SEO & Performance Marketing Agency with offices in Madrid and Milan serving clients in 20+ markets and 10+ languages.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 22 contacts → | ||||
Partial evidence “Posicionamiento Web SEO, Marketing Online y diseño de páginas web en Marbella.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 21 contacts → | ||||
Indirect evidence “Liten Lemon es una agencia de marketing digital ubicada en Madrid, España.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 20 contacts → | ||||
Partial evidence “Sembi Communication is a Digital Marketing Agency experts in SEO (Search Engine Optimization),(Search Engine Marketing), Media Digital Content, Web Design, Community Manager &…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 15 contacts → | ||||
Indirect evidence “Services of Digital Strategy, Online Marketing and Development of websites and applications in web environment and mobile applications.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 15 contacts → | ||||
Partial evidence “Seocoaching es una empresa especializada en posicionamiento web con resultados comprobados y servicios SEO garantizados.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 14 contacts → | ||||
Indirect evidence “Novaigrup, agencia de ingeniería web y marketing en Internet.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 13 contacts → | ||||
Indirect evidence “Estudio34 is an online marketing agency based in Barcelona (Spain) that provides digital marketing services to businesses that either need to improve their online visibility or…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 13 contacts → | ||||
Indirect evidence “In Optimanova we understand Web Optimisation as a way to take the best advantage from your website.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 11 contacts → | ||||
Indirect evidence “With roots and inspiration in Barcelona's iconic Pueblo Seco, Palo Seco is a digital marketing agency that empowers businesses like yours to achieve their online goals.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 11 contacts → | ||||
Indirect evidence “AGENCIA SEOCLIC Somos una Agencia especializada en posicionamiento online, y que cubrimos diferentes servicios relacionados con el Marketing Digital.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 10 contacts → | ||||
Partial evidence “De la mà d’Eva Olivares i Xevi Sañé neix la primera agència 100% SEO a Girona.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 10 contacts → | ||||
Partial evidence “Agencia especializada en el mundo del marketing online: SEO, CRO y Analítica Web.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 9 contacts → | ||||
Partial evidence “Lacomunicación es una agencia de Marketing Digital en Valencia pionera en la consultoría SEO y el marketing digital, servicios que llevamos prestando desde 2004.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 9 contacts → | ||||
Partial evidence “SEOLeverage is an International e-commerce SEO agency with over 20 years of SEO experience.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 9 contacts → | ||||
Indirect evidence “Optimizamos sitios Web de empresas para que incrementen su tráfico desde buscadores y les ayudamos a implementar Google Analitycs para controlar sus inversiones de marketing…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 9 contacts → | ||||
Partial evidence “Nuestra agencia de Marketing Online 360º, forma parte del Grupo QDQ: posicionamiento web en buscadores SEO y SEM, analítica web y conversión.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: cross-border SEO agencies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names cross-border SEO agencies.
- Partial evidence
- Its own public description names part of cross-border SEO agencies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name cross-border SEO agencies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 364 cross-border SEO agencies based in Spain
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Cross-border SEO agencies based in Spain at a glance
As of Sep 27, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for Spain, so it is reported there. Company counts and contact totals on this page are exact for Spain, over 364 companies.
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among cross-border SEO agencies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in Spain whose own description of what they do matches “cross-border SEO agencies”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names cross-border SEO agencies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among cross-border SEO agencies, and records with no verified work email. Companies headquartered outside Spain are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 305 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 27, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Cross-border SEO agencies by metro
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names cross-border SEO agencies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many cross-border SEO agencies are there based in Spain?
RevenueBase identified 364 cross-border SEO agencies headquartered in Spain as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
Bigseo, headquartered in Barcelona, tops this list with the largest team on record.
Which city has the most cross-border SEO agencies?
Barcelona leads with 57 headquartered companies, followed by Madrid (57) and Valencia (22).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 305 verified decision-maker contacts tracked across these 364 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 27, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
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