Big companies rarely struggle with SEO because of a missing keyword list. The trouble usually starts at scale: thousands of product or service pages, several markets and languages, a CMS owned by another department, and a leadership team that wants search tied to revenue.
That changes what a good SEO partner looks like. A firm that runs a tidy program for a 200-page site may stall when every technical fix needs a ticket, a sprint slot, and sign-off from legal. AI answers in Google, ChatGPT, and Perplexity add one more layer to track. Below are the six best firms that can cover those needs and more for large brands.
How We Selected These SEO Firms
We started with a longer list of firms that openly market enterprise or large-brand work. Then we reviewed each company’s website, service pages, case studies, and third-party recognition in September 2026. Firms that shared only vague claims and no measurable results didn’t make the cut.
We also looked for proof that each firm can handle enterprise conditions. Every firm was compared on the same factors:
- Enterprise strength: What it does well once a site gets big and complex.
- AI search work: Whether it has a defined offer for AI Overviews and LLM answers.
- Public proof: A specific, published result or independent award.
- Scope: How much of the work the firm covers beyond organic search.
We didn’t rank on price. Most enterprise firms quote custom scopes, so published numbers rarely compare like-for-like.
The Best SEO Firms for Large Companies
Here’s a quick overview before the detailed reviews:
1. SeoProfy
SeoProfy is an ROI-driven SEO partner that treats organic search as a revenue channel with forecasts attached. Its enterprise program covers technical and content audits, keyword mapping by business segment, on-page and off-page work, international campaigns, governance, and reporting. AI search visibility sits inside the same program rather than in a separate contract.
The company has 13+ years in international SEO, a team of 100+ specialists, and experience in 45+ countries and 15+ languages. Clients stay for 21 months on average. Published results include 329% traffic growth for forex broker FXTM across six priority markets, from 43.6K to 186.9K monthly visits; 509% organic traffic growth for crypto exchange Changelly within nine months; 181% more AI citations for trading analytics platform ATAS.
SeoProfy also publishes price guidance, which is rare at this level. Enterprise work usually starts at $7,000 to $8,000 per month and reaches $15,000 to $20,000+ for multi-market campaigns.
Keep in mind: The firm expects clients to have in-house dev and marketing capacity for implementation, and it’s upfront that meaningful growth takes 6 to 12 months.
2. Seer Interactive
Seer Interactive, founded by Wil Reynolds in 2002, is known for treating SEO as a data problem. Its SeerSignals platform draws on 8.2 billion rows of SERP data, and the team builds reporting with Google Cloud and Looker.
The firm works with 130+ enterprise clients, reports 92% client retention, and holds B Corp certification. Its original research on AI Overviews, including a finding of a 67% organic CTR decline when a brand isn’t cited, gets picked up by major marketing publications.
Keep in mind: Seer also sells paid media, analytics, and CRO, so confirm how much of your budget goes to organic search.
3. Amsive
Amsive is a performance marketing agency with a strong technical SEO team. In 2025, it won Agency of the Year for SEO and Best Overall SEO Initiative for Enterprise at the Search Engine Land Awards. Both wins came from its MSN project, which recovered global visibility and drove 825 million clicks without a single content edit.
That kind of result matters for publishers and large content sites where the fix sits in the code, templates, and indexing rules. Amsive also serves healthcare, financial services, insurance, and education brands.
Keep in mind: SEO is one part of a broader media and audience business, so ask who leads your account day to day.
4. Siege Media
Siege Media builds organic growth through content, design, and digital PR. Founder Ross Hudgens wrote a book on generative engine optimization and the firm now sells full-service GEO
Its client list includes Airbnb, Zapier, Zendesk, and Instacart. For Zapier, Siege reports a $7.2M increase in traffic value and a 290% growth in monthly organic traffic. For Instacart, it reports 46.5K citations in LLMs and a 356% rise in traffic value.
Keep in mind: The model leans on content and links. Companies with deep technical debt may need a separate technical partner.
5. Go Fish Digital
Go Fish Digital is a Raleigh-based firm with 20 years in search and offices in Boston, DC, Phoenix, San Diego, and Jacksonville. It combines SEO and GEO with digital PR, reputation management, paid search, and social commerce.
The team built its own research tool, Barracuda, along with Chrome extensions used by many SEO specialists. On the results side, MoneyGeek saw clicks grow from 67.5K to 118K, and SimpleTexting reported a 500% YoY rise in organic SQLs.
Keep in mind: Several highlighted case studies focus on TikTok Shop and paid channels, so ask for enterprise SEO examples close to your industry.
6. Directive
Directive focuses on B2B technology companies and measures marketing by qualified pipeline instead of lead counts. It has served 420+ brands, including Adobe and Calendly, and tracks AI visibility through its own Stratos platform.
Its SEO work combines technical fixes, content, and link building with GEO and AI Overview optimization. For Sumo Logic, a content program around cloud security topics brought a 38% lift in impressions, or 4.3 million additional impressions within a quarter.
Keep in mind: Directive is a strong match for B2B SaaS. Retail and consumer brands will likely find better fits above.
What Big Companies Need From an SEO Partner
At the enterprise level, most of the SEO effort goes into getting work shipped inside a large organization. A single template change can affect 50,000 pages at once, for better or worse. That’s why process and communication often decide results.
Most large brands need a partner that can handle four things well:
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Technical scale: Crawling, indexing, site migrations, and internal linking across huge URL sets.
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Governance: Clear rules for how regional and product teams publish pages without creating duplicates.
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Measurement: Reporting tied to revenue, pipeline, or leads, not only rankings.
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AI visibility: Tracking how often the brand appears in AI Overviews and chatbot answers.
The size of the firm matters less here than senior people on the account and a realistic plan for implementation.
How to Choose the Right SEO Firm for a Big Company
A shortlist is only useful if you test it against your own site. Start by listing the constraints that slow SEO down internally. Developer capacity, content approvals, and regional teams often matter more than any tactic.
Then ask each firm the same questions:
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Which enterprise projects look most like ours in size and industry?
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How do you forecast results, and what happens if targets slip?
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Who implements technical changes, and how do you work with our developers?
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How do you track visibility in AI Overviews and LLM answers?
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What does reporting look like for our CMO or CFO?
Technical depth deserves extra attention for sites with hundreds of thousands of URLs. Google’s own guide to managing crawl budget applies to sites with a million or more pages, and a strong partner should explain how they handle crawling and indexing without reaching for jargon.
Finally, look at how long clients stay. Enterprise SEO takes months to compound, and high retention usually signals that a firm delivers steady business results over time.
