You are an enterprise SEO director. You need to move your 500,000-page e-commerce site within 90 days, and ChatGPT isn’t showing your brand name in its zero-click response. Choosing the wrong agency means losing six months to regain lost organic traffic and having to justify a 40% drop in revenue to your board.
Many agencies can discuss the technicalities of SEO, but they get nervous when you bring up JavaScript rendering chains, global hreflang deployment, or optimization for Perplexity citations. And most don’t realize that Google’s Search Generative Experience and ChatGPT’s browsing feature have completely redefined how to rank in complex sites.
Enterprise SEO agencies vary greatly in their technical knowledge and generative search capabilities, and we review the 7 that work for large sites and generative engines. We rated each firm based on its ability to handle a site migration, expertise in generative engine optimization, past experience working with large-scale sites, direct communication with experienced professionals, and whether the firm prioritizes strategies that align with revenue growth.
Some firms focus exclusively on technical SEO analysis, while others are early adopters of new generative engine visibility tools. Here is a comparison of the top 7.
How to Shortcut this List
There are three types of enterprise SEOs: technical SEOs who dig into complex site architectures; AI search specialists who help brands build their presence on generative search engines; and the full-stack SEOs who combine both skill sets with content strategy.
- Technical-first rebuilds: Organic Hackers, SALT.Agency, Screaming Frog.
- AI search positioning leaders: Onely, iPullRank, Nectiv.
- Data-driven partnerships: Greenlane Marketing.
Top 7 Enterprise SEO Agencies
The agencies listed below have proven they can navigate multi-site websites, large-scale technical projects, or lead the way in AI search optimization. These are areas that require unique skills outside of a typical SEO strategy.
Organic Hackers
Organic Hackers is a tech-first SEO agency focused on large and complex websites. Its approach combines technical SEO with revenue-focused strategy to improve website visibility, traffic, and sales. The agency works on areas such as technical SEO, website migrations, ecommerce website structure, Core Web Vitals, and site architecture.
A key part of its model is working directly with internal or external development teams. Organic Hackers provides technical specifications for technologies such as Shopify Liquid, React/Next.js, and server configurations, helping development teams implement SEO recommendations accurately.
The agency also focuses on complex technical issues that can affect crawling, indexing, and search performance, including JavaScript rendering, crawl budget, international site architecture, and indexation. For ecommerce websites, its services include shopping experiences, website structure, and performance optimization.
Organic Hackers also offers SEO strategies for AI-driven search, including Google AI Overviews, ChatGPT, and Perplexity. Its approach includes adapting website architecture for easier retrieval by AI search systems and using custom monitoring dashboards to track performance. A free Tech SEO Audit session is also available.
- Technical SEO and developer guidance for large websites
- Expertise in migrations, JavaScript rendering, crawl budget, and indexation
- Ecommerce website structure and performance optimization
- AI search optimization for Google AI Overviews, ChatGPT, and Perplexity
- Free Tech SEO Audit session available
Onely
Onely is a technical SEO agency focused on complex enterprise websites. Its work covers technical audits, server log analysis, JavaScript rendering, information architecture, migrations, international SEO, and recovery from visibility drops.
The agency also works on generative engine optimization and AI search, applying its technical SEO expertise to how websites are discovered and represented across emerging search platforms.
Its services are suited to businesses managing large or technically complex websites where technical issues can affect crawling, indexing, and search visibility.
- Advanced technical SEO audits with server log and JavaScript analysis
- GEO & AI search optimization for generative engine visibility
- Site migration and international SEO specialization
- Visibility drop recovery when algorithm changes strike
iPullRank
iPullRank is an enterprise search agency covering technical SEO, content strategy, digital PR, and AI search optimization. Its Relevance Engineering approach combines search technology, information retrieval, content, and audience research to address how brands are discovered by both search engines and AI platforms.
The agency also provides GEO and content strategy services, with a focus on improving visibility across traditional and AI-driven search. Its broader approach combines technical optimization with content and digital PR for enterprise websites.
- AI Search optimization via proprietary Relevance Engineering methodology
- Audience Research and Digital PR for brand authority at scale
- 15 years delivering enterprise-grade Technical SEO
- Content Strategy designed for resonance, not just relevance
SALT.agency
SALT.agency specializes in technical SEO for large and complex websites. Its services include JavaScript rendering optimization, website architecture analysis, server log analysis, migrations, international SEO, and AI search optimization.
The agency works directly with development and marketing teams to support the implementation of technical recommendations. Its focus on technical SEO and AI search makes it relevant for enterprises managing large websites, complex architectures, and ongoing technical changes.
- Direct expert access eliminates consultant translation lag
- Pioneering AI search optimization for generative engines
- JavaScript rendering and server log analysis expertise
- Hands-on collaboration with dev and marketing teams
Greenlane Marketing
Greenlane Marketing is a digital marketing agency offering technical SEO, on-page optimization, link building, local SEO, UX, and performance analysis. Its approach focuses on building data-informed strategies around each client’s specific needs rather than using a standardized SEO model.
The agency works with both local and national brands and combines technical SEO with broader search, analytics, and UX services. This makes its offering suitable for businesses looking to connect technical improvements with wider marketing goals.
- 14 years delivering ROI-focused search strategies
- Holistic approach: technical SEO, content, analytics, and UX
- Local SEO and link acquisition expertise for multi-location brands
- Philadelphia-based team serving national enterprise clients
Screaming Frog
Screaming Frog combines SEO services with its well-known SEO Spider website crawling tool. Its technical SEO work covers areas such as broken links, duplicate content, site architecture, and website audits, while the crawler helps identify technical issues across large websites.
The agency also provides SEO, PPC, and link-building services. Its combination of technical SEO expertise and proprietary crawling software makes it relevant for businesses dealing with complex websites, audits, and migrations.
- 26+ years in the market with an agency and software dual model
- Proprietary crawler used by Apple, Google, Disney, Amazon
- Integrates with GA, Search Console, PageSpeed Insights natively
- Bulk licensing from $235/user/year for 20+ seats
- Free crawler version available for small-scale audits
Nectiv
Nectiv is a search acquisition agency focused on B2B and technology companies. Its services cover traditional SEO alongside AEO and AI search optimization, including technical SEO, content, off-page SEO, competitive analysis, and AI visibility.
The agency uses proprietary tools to monitor visibility across platforms such as ChatGPT, Perplexity, and Google AI search. Its approach also includes adaptive workflows that adjust priorities based on implementation effort, potential impact, and performance data.
- AI visibility tracking across 5+ generative engines
- Adaptive workflows adjust to performance data monthly
- B2B/tech specialist for $20M+ ARR brands
- Combines strategy and execution with proprietary tools
Conclusion
Enterprise SEO for large sites demands both technical expertise and AI search optimization. Here are seven top agencies that fit the bill.
These seven companies fall into two distinct categories: Technical SEO firms and holistic SEO firms. Technical firms are best suited for sites undergoing migrations or using frameworks like JavaScript. Holistic SEO firms are more suited for sites looking to do extensive audience research, as well as optimize content and UX at scale.
Ultimately, which firm you hire depends on whether you’re looking for highly focused technical support or a 360-degree strategic partnership. Start by asking for audits from two agencies in different camps and see how their diagnostic depth and AI search roadmaps stack up side-by-side. Whichever firm finds issues your current team doesn’t have answers for and presents a detailed GEO roadmap should be the one you hire.