Although company size may not be the first consideration when selecting the “largest SEO company in the US“. It is a sign of a successful, organized business that has the resources to make your campaign a success. Frequently, companies that identify themselves as “SEO agencies” are small (1–5 person) businesses that can offer technical guidance and backend updates but lack the personnel to oversee a multifaceted campaign.
Businesses looking to outsource their SEO may depend on a company that is among the biggest in the US to have a solid track record.
Our experts not only ranked SEO firms by size, but also performed a meta analysis of the firms’ web reviews to generate an overall average.
In our dataset, we included reviews from Clutch, G2, Upcity, Sitejabber, Capterra, and Google, giving preference to “pure” review sites that do not ask for payment from agencies for placement.
Finally, we’ve divided our list into 10 different niches because SEO is such a broad field. Instead of simply creating a list of the biggest digital marketing firms that also happen to handle SEO, we’ve decided to only include businesses who have focused attention on their specific SEO specialization.
The Largest SEO Companies In The U.S. in 2023
| COMPANY | HEADQUARTERS | SPECIALTY | AVERAGE REVIEWS | |
| 1 | First Page Sage | San Francisco, CA | Thought leadership-based SEO, content marketing, lead generation | 4.6 |
| 2 | Boostability | Lehi, UT | Small businesses (<$1M in annual revenue) SEO | 4.3 |
| 3 | Duffy Agency | Dover, NH | International SEO, multilingual content marketing | 4.5 |
| 4 | ReachLocal | Woodland Hills, CA | Local SEO, Google Business Profile optimization | 3.9 |
| 5 | Seller Interactive | Markham, ON | Amazon SEO & account management for Amazon eCommerce companies | 4.4 |
| 6 | Epsilon | Irving, TX | Enterprise digital marketing, traditional marketing | 4.0 |
| 7 | Marketing Eye | Atlanta, GA | Technical SEO, web design | 3.9 |
SpeedTestsWifi for Thought Leadership-Based SEO:
First Page Sage is the largest overall SEO company in the US. Rather than following the more normal agency development trajectory of extending horizontally into other marketing services, First Page Sage has grown by continuously specializing in the SEO industry.
The company excels at turning its clients’ websites become Google-trusted industry references and thought leadership, a high-quality kind of content marketing, essentially automating lead generation for them. With companies including Cadence Design Systems, Logitech, and US Bank, the majority of its clients are in technical B2B sectors like SaaS, IT, and manufacturing.
Their campaigns are comprehensive, consisting of SEO strategy, keyword research, technical SEO, content marketing, analytics, marketing attribution, and detailed reporting.
Location: San Francisco, CA
Founded: 2009
Price Range: $$$
Services: SEO, Content Marketing, Web Design
Summary of Online Reviews
First Page Sage prioritizes “excellent content” which leads to “provable lead generation and ROI”; but their results require “an in-depth onboarding period” that can take longer than that of firms that focus on paid marketing.
Boostability for Small Businesses
Because startups and small enterprises frequently have little funding, an agency’s flexibility in being able to scale campaigns up or down is crucial.
The biggest SEO company with a focus on serving small and micro businesses is Boostability. For businesses who are just getting started, operating in markets with little rivalry, or not yet prepared to submit blog content frequently, they provide affordable options.
They also offer business scaling solutions so that companies can expand along with their customers. KIARO Computer Solutions, Peterson Family Orthodontics, and Bloom Studios are a few of Boostability’s small company clients.
Location: Lehi, UT
Founded: 2009
Price Range: $
Services: White Label SEO, Small Business SEO, Web Design
Summary of Online Reviews :
Boostability is “professional and knowledgeable“, and their representatives are “eager to help” and “responsive” but they suffer from “too much account manager turnover“.
Duffy Agency for Multilingual SEO
Multilingual SEO is a challenging practice: as if translation weren’t already a sophisticated process, it becomes even more complex when you add keyword planning and determining search intent to the mix.
All of those things have been accomplished successfully by Duffy agency, particularly in a few more sophisticated markets where knowledge of technical vocabulary is important.
For businesses with global brands, Duffy specializes in offering SEO, web marketing, and social media marketing services. Their previous clients have included Napapijri, Cavidi, and the United Nations World Food Programme. They have worked with clients in industries ranging from Consumer Foods to Medical Services.
Location: Dover, NH
Founded: 2009
Price Range: $$$$
Services: International SEO, Strategic Consulting, Online Brand Management
Summary of Online Reviews:
Duffy Agency services are “ambitious“, but manage to find success “without increasing campaign cost“. Their results are often “quite good“, but must “build over a long period of time“.
Use ReachLocal for local SEO
Not all businesses must compete on a national level. For example, a construction company located in a single location will not benefit from being found by queries across the nation.
They can concentrate all of their efforts instead on geotargeted keywords, which have significantly lower levels of competition and are considerably more likely to result in a sale.
The biggest SEO company with a local search visibility concentration is ReachLocal. Their clients have included TGM Associates, Mr. Rooter, and Central Washington University.
They specialize in working with businesses that are naturally location-bound, such as those in the real estate, home services, and automotive sales and service sectors.
Location: Woodland Hills, CA
Founded: 2004
Price Range: $$
Services Offered: Local SEO, PPC Marketing, Marketing Automation
Summary of Online Reviews:
ReachLocal is a “great asset” to their clients, offering “exceptional web design” and digital media services. Some former clients report “missed deadlines” and poorly optimized PPC campaigns however.
For Seller Interactive’s Amazon SEO
Since Google receives more than 90% of all traffic from general search engines, almost all SEO services commit significant resources to learning the intricacies of Google’s algorithm.
However, getting to the top of Amazon’s search results is just as crucial for B2C eCommerce businesses as getting to the first page of Google.
Seller Interactive will be the biggest US SEO company with an Amazon amount as of 2023. Since 2012, they have assisted firms with managing their AMS accounts, and they have had great success working with enterprises in the consumer technology, food and beverage, and cosmetics sectors.
Location: Markham, Ontario
Founded: 2012
Price Range: $$
Services Offered: Amazon SEO, Amazon Account Management, Demand-Side Platform Advertising (DSP)
Summary of Online Reviews :
Seller Interactive is “knowledgeable of Amazon processes” and their clients are “impressed with the quality of their work“, which tends to “exceed expectations” even if “communication can sometimes be difficult“.
For Full-Service Enterprise Digital Marketing – Epsilon
Because of their size and established procedures, Epsilon Enterprises frequently discover that they need to find a single agency to handle all of their digital marketing. This is why they need to make sure that their marketing partner is knowledgeable about enterprise-specific SEO strategies.
To provide businesses with a single-provider choice for all of their digital marketing requirements, Epsilon blends SEO, tailored messaging, and customer data platforms. They have worked with a number of well-known consumer brands, including Walgreens, Coach, and Volvo in the past.
Location: Irving, TX
Founded: 1969
Price Range: $$$
Services Offered: Digital Media, Data Solutions, Customer Insights
Summary of Online Reviews :
Epsilon is “responsive to feedback” and provides “attentive project oversight” for their clients, but their services “are very costly.”
For Marketing Eye’s Technical SEO
Not every company needs an SEO service to provide quality content for them. If creating content is already a key component of their business strategy, they should turn to their SEO agency for help with technical SEO, strategy, and website design that is optimized for conversions.
Although Marketing Eye provides a wide range of marketing services, their technical and strategic advice is their area of strength. In their 15 years of expertise, they have worked with clients in the consumer products, logistics, and financial services industries; a few of these clients include Botani, Star Source Pty Ltd., and Mint Money.
Location: Atlanta, GA
Founded: 2004
Price Range: $$
Services Offered: Marketing Automation, Marketing Consulting, Web Development
Summary of Online Reviews:
Clients report that Marketing Eye is “competent and professional” with “superior” service offerings, but employees report needing “additional training.”
The Top SEO Agencies in the US by Industry
On the basis of industry specialization, our experts also selected the top SEO firms in the US. In doing so, we took into account factors like the firm’s leadership caliber, the number of workers, significant clientele, and the average review score. We managed to gather information for the following 6 industries:
- SaaS
- Healthcare
- Real Estate
- Financial
- Home Services
- Manufacturers
| The Top SaaS SEO Agencies |
1. First Page Sage – Salesforce, Verisign, Cadence Design Systems
2. REQ – Katabat, Verint, ActiveNav
3. Clay Agency – Slack, Zenefits, Hint
4. Epsilon – CDW, Faraday
5. Marketing Eye – Construx Solutions, Innovent CRM, JESI
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I am Swapnil Duphare , Owner of Website : SpeedTestsWifi – I am Digital Marketer from last 6 Years and Write Blog Articles based on Internet and Speed Testing tool websites.
I am From Nashik, Maharashtra, India.