SEO agencies in the United States
SEO has transformed remarkably—it has evolved from primarily a technical task handled by search engine optimization agencies to a strategic approach around quality content and user experience.
Only SEO firms that prioritize user-centric strategies and human-first content will thrive in today’s highly competitive, AI-driven market.
If you’re searching for the best search engine optimization agency to establish authority in your industry and build trust with your audience (the new performance indicators), you’re in the right place.
Our curated list features the best SEO firms with time-tested portfolios for business success. We carefully analyzed a variety of top-rated companies based on their client reviews, overall reputation, pricing, specialty, and more.
Follow our proven steps to shortlist the best SEO agencies, or use our advanced “Get Matched” feature to find the most suitable SEO company for you.
What is SEO?
A lot has changed in approaches to SEO, but it can still be defined as the practices, actions, and strategies used to improve a website’s visibility on search engine results pages (SERPs).
In the past, many SEO firms focused solely on ranking higher, often using black-hat techniques to trick algorithms. However, advanced algorithms have rendered these tactics ineffective. Modern search engines prioritize helpful, high-quality content.
While some believe SEO is less relevant in the age of AI, over 90% of online experiences still start with a search engine. That’s a massive audience, and capturing even a small portion of that can significantly impact a business.
Today’s search engines are highly sophisticated, going beyond keywords to interpret human intents. With AI, they can even understand implicit preferences—such as specific cravings—and recommend the best options based on location. It’s a lot for a business to manage, but this is where search engine optimization agencies can really make a difference.
What Do US-Based SEO Firms Do?
Good SEO service companies optimize your site to meet search engine guidelines, creating a strong connection between your brand and your ideal customer.
Their goal is to ensure that when someone searches for the solutions you offer, your website isn't just visible—it’s irresistible.
The success of SEO firms depends on delivering the most relevant, helpful, and user-friendly answers, often addressing unspoken queries or doubts.
Achieving this demands intuition, foresight, strategic planning, and experience-driven expertise—all of which are essential in today’s SEO landscape.
The process that good SEO firms follow can be divided into the following core tasks:
Audits:
Regular SEO audits can measure milestones and progress by identifying weaknesses, strengths, and opportunities to improve and adapt to algorithm changes.Keyword research:
An SEO service company will identify and analyze phrases that potential customers use to find your products or services.Competitor analysis:
Competitor analysis makes you more likely to outperform your competitors in search rankings through benchmarking and identifying gaps.Content marketing:
Content marketing, which involves publishing relevant and valuable content, can offer a user experience that results in six times higher conversion rates than those that don't leverage it.Off-page optimization:
The best SEO agencies strive to establish your website's authority through external methods like backlink building (one of Google's top three ranking factors) and social media engagement.On-page optimization:
Semrush’s on-page optimization checklist enables individual web pages to rank higher by using strategies such as optimizing meta tags, headers, and content structure. This can increase organic traffic by allowing users to easily find you when they need you.Technical SEO:
A one-second delay in page load time can lead to a 7% reduction in conversions. Through technical SEO, search engine optimization agencies can ensure your pages meet such search engine requirements as site speed, mobile-friendliness, and secure connections.Local SEO:
46% of all Google searches are seeking local information, so there’s a huge opportunity to optimize your online presence to attract more business from relevant local searches.Reporting and analysis:
The best SEO service companies will provide regular reports on SEO performance, including traffic metrics, keyword rankings, and ROI, to inform strategy adjustments. Utilizing analytics makes it 5 times more likely you will make better decisions.Mobile SEO:
Responsive, mobile-first designs that ensure a seamless experience across all devices can help you attract over 83% of Google searches that are conducted on mobile devices.
Why Should I Hire a Search Engine Optimization Agency?
Securing a top position in search rankings is incredibly valuable, with the #1 result on Google capturing about 39.8% of all clicks.
Modern search engine optimization agencies leverage pivotal trends that once seemed impossible.
For example, SEO firms can integrate AI into your marketing efforts to optimize your site for AI-driven search experiences like Google’s Search Generative Experience (SGE).
A more nuanced SEO strategy is essential in this landscape, and professional expertise can make all the difference.
Moreover, a professional SEO agency will bring the following to the table:
Expertise and experience:
The best companies for SEO offer specialized knowledge and stay up-to-date with the latest algorithm changes and industry trends.Time and resource efficiency:
Outsourcing SEO allows you to focus on core business activities while the experts handle optimization.Measurable ROI:
Choosing the best SEO agency can let you implement strategies that bring higher conversion rates and increased revenue, which you can track and measure.Access to advanced tools:
Sophisticated SEO tools and technologies can often be cost-prohibitive for individual businesses. Hiring an SEO agency gives you access to those tools at a fraction of the cost.
How Do I Choose an SEO Agency For My Business?
When hiring an SEO agency, ensure that it prioritizes E-E-A-T (Experience, Expertise, Authoritativeness, and Trustworthiness).
Google's latest guidelines clarify that while AI-enhanced content isn’t penalized, it must embody these attributes.
There’s a strong shift toward a new standard of user-centric content, with valuable, comprehensive, human-first material for meeting user intent and boosting engagement.
A well-executed strategy from SEO firms remains essential for sustainable growth.
That’s why selecting the best company for SEO has to be a well-thought-out decision. Follow these steps:
Check Semrush’s ranking:
Semrush rankings are based on client reviews, service offerings, and overall performance. We take into account the agency’s portfolio and prior success stories. Our insights match you with the best-fit, top-performing marketing and SEO agencies.Check Google Reviews:
Google Reviews is a reliable, unbiased, and publicly-vetted place to gauge client satisfaction and reliability. Positive reviews and high ratings are indicators of trustworthiness and quality of service.Consider location:
A local agency allows for face-to-face interactions, while a remote agency can often meet your needs in ways that local SEO companies can’t.Review the agency's website:
Is your search engine optimization agency doing its own SEO? Is their website professional and responsive? Does it demonstrate evidence of expertise? The best companies for SEO should have a well-designed website, demonstrating their own commitment to quality and attention to detail.Read client testimonials and review case studies:
Past successes, particularly with similar businesses, can indicate legitimacy. In the same way, case studies that show proven improvements in search rankings or traffic can be very instructive.Evaluate success stories:
To find the best company for SEO, study their clients’ accounts of how the agency delivered better results for them. Authentic and well-presented success stories should demonstrate their problem-solving abilities and strategic approaches.Submit a Request for Proposal (RFP):
When you reach out to search engine optimization agencies with specific project requirements, they should send you a tailored proposal. This will show how well the SEO firms understand and will address your needs in their proposed solutions.Use matching services:
If the selection process seems overwhelming, consider using services that match businesses with the best company for SEO. Semrush offers curated lists and matching tools to simplify your search with a single click.
What Red Flags to Watch Out for When Hiring An SEO Service Company?
Choosing the wrong SEO service company for your needs can put you back several months or even years. Potential risks, poor service, or unethical practices can ultimately lead to penalties, so be mindful of the following warning signs when selecting an SEO agency:
Not offering SEO audits
A professional SEO agency audit will assess your current online presence, website structure, content, and technical aspects that affect search engine rankings. If an SEO service company skips this step, they are probably not committed to personalization.Guaranteeing results
Agencies that guarantee first-page rankings or specific outcomes can be a red flag. While a reputable SEO service company can provide strategies to improve rankings, it cannot promise specific positions, as search engine algorithms are constantly evolving.Lack of transparency
SEO agencies that are unwilling to share their methods or provide clear explanations about their strategies should raise suspicion. The best companies for SEO will communicate openly about the strategies they are using, the tools they employ, and the progress they have made.Black-hat tactics
Black-hat SEO has long been considered a big no-no—keyword stuffing, cloaking, or using private link networks are bound to fail. Always choose an SEO service company that adheres to white-hat, ethical SEO practices.Outdated or low-quality content
If an agency offers low-quality, outdated content, or focuses on quantity over quality, it could negatively impact your site's ranking. A good SEO firm will align with current SEO best practices.Lack of case studies or testimonials
Without solid case studies or testimonials, you cannot be sure that the agency can deliver results as impressive as they claim. Find a company with proven success in your industry.Overemphasis on link building
Focusing too much on link-building can backfire. The best companies for SEO will balance link building with other tactics for a holistic SEO strategy.No clear reporting or analytics
The best SEO agencies will offer detailed reports and analytics, including such metrics as organic traffic, keyword rankings, conversion rates, and other KPIs. Lack of reporting or overly vague reports are signs that the agency may not be delivering measurable results.
What Are the Key Success Metrics for the Best SEO Companies?
Any good SEO service company must track
Organic traffic
Their key focus should be driving more organic traffic. Higher organic, quality traffic means more relevant visitors are discovering your business through unpaid search results.Keyword rankings
The best SEO agencies will aim to improve rankings for high-volume, relevant keywords that attract qualified leads to your website.Click-Through Rate (CTR)
The quality of your snippets, titles, and tags determines your CTR, which measures the percentage of people who click on your website’s link after seeing it in search results.Referring domains
The more high-quality referring domains you have, the more authoritative your website appears to search engines.Pages per session
Organic search visitors visit up to 3.5 pages per session. Google likes it when your users switch from one page to another on your site in a single session, and this is something your SEO service company should be measuring.Average session duration
A longer session duration suggests that users find your content valuable, which can lead to better rankings and a lower bounce rate.Time on page
If users spend a significant amount of time on your pages, it indicates that your content is relevant and engaging.Bounce rate
The top three domains have an average bounce rate of 49%. A high bounce rate may suggest that your landing pages aren’t optimized for what users expect.Exit rate
SEO firms should track and fix high exit rates. These suggest that your content isn’t compelling enough to keep users on the site.Core Web Vitals
Core Web Vitals are a set of metrics related to the user experience of a website that are used by the best SEO agencies. They include metrics such as loading performance and visual stability.Indexed pages
The best search engine optimization agencies will ensure that all important pages of your site are indexed properly for maximum visibility.Organic traffic conversions
It is no good to have 100,000 visitors if they don’t become your customers. That’s where a good SEO agency will distinguish performance instead of claiming numbers without an impact. Monitoring conversion rates will allow you to see whether increased traffic is translating into real business results.
What Questions Should I Ask the Best SEO Agencies Before Hiring One?
Relevant Background
Have you worked with businesses in our industry before?
SEO firms’ familiarity with industry-specific challenges and opportunities can streamline results. Ask for examples and assess their understanding of niche market dynamics.Can you provide case studies or examples from similar clients?
Case studies that showcase measurable outcomes, such as improved rankings, traffic, or conversions, will demonstrate the agency’s expertise. Try to find specifics in their strategies and results.Does your team hold SEO-related certifications or accreditations?
Certifications like Google Analytics or HubSpot indicate that the best SEO agencies stay up-to-date on industry standards.How do you define and measure success in SEO?
What you can’t measure can’t be improved. Your best SEO agencies must focus on tracking success. Organic traffic growth, improved rankings, and ROI are some solid indicators.What is your pricing model, and what are your payment terms?
Transparent pricing helps avoid hidden costs. Understand whether their model is project-based, retainer-based, or hourly, and check if it falls within your budget.
Services and Processes
What specific SEO services do you offer, and do you provide complementary services such as PPC or performance marketing?
You should investigate if your SEO service company is effective at offering related services. If not, you might find yourself having to hire another marketing company to deliver those services.How do you approach keyword research and how will you create an SEO strategy tailored to our business?
Keyword research seems simple with Semrush, but it has to have a clear goal, a strategy, some foresight, and intuition, which comes with experience.What is your methodology for link building, and how do you ensure the quality of backlinks?
Avoid SEO firms focusing solely on quantity. They should prioritize authoritative and relevant backlinks to avoid penalties.How frequently will we receive reports, and what metrics or insights will they include?
Expect regular reporting (monthly or bi-weekly) with clear insights into traffic, rankings, and campaign progress.Which tools and platforms do you use for SEO, and can we access them if needed?
Search engine optimization agencies that use industry-standard tools such as Semrush are more likely to provide accurate data. Transparency in tool usage is a must-have.How do you keep up with search engine algorithm updates and industry trends?
Continuous learning and adaptability can be stressful but are very important here for long-term success. Ensure that your shortlisted search engine optimization agencies are capable of proactive responses to algorithm changes.
Project-Specific Questions
How will you tailor your SEO strategies to align with our business goals?
Generic, pre-made templates and packaged solutions might not be your best bet. Your objectives and target audience should be unique, and so should your approach.Which SEO tactics do you believe will be most effective for our brand, and why?
Listen for a mix of technical, content, and off-page strategies, backed by reasoning and past successes.What is the expected timeline for seeing measurable results from your efforts?
Genuine agencies set realistic expectations, typically 4–6 months, for noticeable progress.Who will be managing our account, and what is their level of expertise?
Talk to your project manager and ensure you are on the same page. Take note of how well you can communicate with them, and what experience they have when it comes to handling SEO accounts.How will you keep us updated on progress, and which communication channels will you use?
The best companies for SEO should offer clear communication channels and regular updates to ensure you stay informed and involved.What role should we play to ensure the success of our SEO strategy?
Collaboration is essential. The best companies for SEO should outline the type of input or resources they’ll need from you.
Choose Your Agency Now
The right SEO firm for you might have a higher price point than more affordable search engine optimization agencies, but it could still be worth the investment.
In fact, 49% of marketers believe organic search delivers the best ROI among all marketing channels.
If your SEO service company consistently generates measurable results, you’re in good hands.
Use this guide to take the next step in your company’s digital success, and explore the best digital marketing and SEO agencies in the United States listed on this page.