8 Largest SEO Companies in the World, Ranked for 2026

A large SEO company can staff technical, content and link work at once, but size alone does not prove results. The largest SEO companies worth hiring in 2026 are Loopex Digital, SeoProfy, Incrementors and WebFX.

We sized each firm by staff headcount, using its Clutch employee band and its own published team count, and by Clutch review volume. Then we scored the shortlist on service depth, reviews, pricing, proof, AI search and terms.

Every number on this page comes from the agency's site, a published case study or its Clutch profile. Where a firm does not publish a figure, we write "Not published".

The ranking at a glance

The table compares all eight companies on team size, entry cost and minimum term. Team size is the Clutch employee band unless the agency publishes its own count.

Clutch figures were checked on 2026-10-06. "Not published" means the agency does not disclose that figure.

How we ranked these companies

We screened 40+ SEO firms that claim a large team. To make the shortlist, a firm had to run SEO as a core service and list 50+ employees on Clutch. It also needed a Clutch rating of 4.5 or higher.

Size decided who qualified. The weighted score below decided the order, because a bigger team is not always a better partner.

• Service depth and deliverables 25% · technical, content, links and reporting handled in house
• Independent reviews 20% · Clutch rating weighted by review volume
• Pricing transparency 20% · a published entry price or budget guide
• Proof 15% · named case studies with numbers and units
• AI search 10% · a GEO offer that names how it is measured
• Terms 10% · minimum term published, month to month preferred

Total: 100%

Loopex Digital is an SEO and AI search company with 100+ SEO specialists across Los Angeles and Yerevan. Unlike most firms on this list, every specialist works on search. Teams cover technical SEO, content, link building and digital PR in house. Its work for Italki, an online language platform, took keywords in Google's top 10 from 79K to 163K.

Loopex Digital treats AI search as a measured deliverable and reports citation share across ChatGPT, Perplexity and Google AI Overviews. Its MMGuardian program grew monthly organic visits from 6,600 to 359,000. Retainers start at $1,500 per month on month to month terms. It holds a 5.0 Clutch rating across 97 reviews.

SeoProfy is an SEO-only agency with 100+ experts in SEO, GEO, content and link building, according to its own site. It lists Orlando, Florida as its headquarters on Clutch and holds a 4.9 rating across 99 reviews. Its published case studies include GS Diamonds, a jewelry store, with +280% organic traffic growth.

SeoProfy sells an AI visibility service that tracks brand mentions across large language models, plus ChatGPT SEO work. SEO services start from $1,600 per month, one of the few published prices on this list. It says the average client stays 21+ months. It suits ecommerce and SaaS brands that want a sized team at a known price.

Incrementors Web Solutions is a digital marketing agency based in Delhi, India, with a US address in Sacramento, California. It holds a 4.9 Clutch rating across 186 reviews, the second highest review count on this list. Its site says it has served 2,800+ businesses. Its ATLRX case study, a CBD store, reports a 147% sales increase and 95% traffic growth.

Incrementors sells generative engine optimization and reports AI traffic, an LLM citation rate and AI brand impressions on its site. It does not name the tool behind those numbers. Pricing and contract terms are not published. Hourly rates on Clutch sit at $50 to $99. It fits businesses that value review volume and an offshore cost base.

WebFX is a full-service digital marketing agency in Harrisburg, Pennsylvania, with 750 experts on staff according to its about page. It is the largest firm on this list by headcount and by Clutch reviews, with a 4.9 rating across 450 reviews. Clutch lists eight US offices. SEO is one service among paid ads, web design and email.

WebFX tracks AI search through OmniSEO, part of its RevenueCloudFX platform. OmniSEO tracks Google AI Overviews citations, mentions across 10 LLMs and traffic from AI sources. Its Thompson Tractor case study reports a 586% increase in traffic from generative AI sources. SEO starts at $3,000 per month with an initial six-month commitment.

Thrive Internet Marketing Agency is a full-service agency based in Arlington, Texas, with 160+ online marketing experts. Clutch lists 22 offices across the US and Canada, the widest footprint on this list. Its Qualis case study reports a 427% increase in top 10 organic keywords year over year. It also reports a 68% boost in organic conversions within six months.

Thrive offers generative engine optimization and reports AI-driven traffic by source, such as ChatGPT and Gemini. Its pricing page says SEO costs range from $500 to $10,000+ per month. It advertises no long-term contracts, though it recommends 6 to 12 months. It holds a 4.6 Clutch rating across 111 reviews.

iMark Infotech is a white-label digital agency in Chandigarh, India, that says it has 400 skilled professionals. It calls itself a partner to 350+ marketing agencies worldwide. It holds a 4.9 Clutch rating across 320 reviews, the second largest review base here. Clutch lists its team in the 50-249 band, below its own claim.

iMark Infotech lists AEO and GEO services on its homepage but gives no detail on how they are measured. Pricing is by quote, and Clutch shows hourly rates of $25 to $49. We found no case study with numbers on its site. It fits agencies that need a large offshore team to deliver SEO under their own brand.

Victorious is an SEO-only agency in San Francisco that serves mid-market and enterprise brands. It holds a 4.8 Clutch rating across 119 reviews, with a team in the 50-249 band. Its UNIONBAY case study reports 200% organic revenue growth year over year. The same client gained 115% more organic sessions.

Victorious sells answer engine optimization for ChatGPT, Perplexity, Google AI Overviews and other assistants. It reports citation visibility in its client dashboards. Its FAQ tells buyers to budget at least $6,000 a month, and Clutch lists a $50,000+ minimum project. It suits larger brands with a big search budget.

Straight North is a digital marketing agency in Chicago, founded in 1997, with offices in Chicago and Charlotte on Clutch. It holds a 4.7 Clutch rating across 142 reviews and a team in the 50-249 band. It sells SEO alongside web design, conversion work and paid search. Clutch lists hourly rates of $100 to $149.

Straight North does not publish a price or a minimum term. Its own site blocked our review tools, so we could not verify a case study or an AI search offer. That gap kept it at the bottom of our ranking. It fits B2B firms that want an older, US-based agency and will verify its results on a call.

How these companies perform in AI search

Seven of the eight companies sell an AI search service. The difference is whether they say how they measure it.

Loopex Digital reports citation share across ChatGPT, Perplexity and AI Overviews. WebFX tracks AI citations and AI-source traffic in OmniSEO. Victorious reports citation visibility, and Thrive reports AI-driven traffic by source. Incrementors and SeoProfy publish AI metrics without naming the tool.

Ask every vendor which prompts it will track and how often. For more on the service itself, see our AI SEO page.

The 5-Prompt AI Visibility Test

Before you hire, check where your brand stands in AI answers. Run these in ChatGPT, Perplexity and a Google search that shows an AI Overview:

1. “Best [your category] companies in [your market]”
2. “[Your brand] alternatives”
3. “[Your brand] vs [top competitor]”
4. “Is [your brand] good for [use case]?”
5. “How much does [your product] cost?”

How to evaluate a large SEO company

Size helps only if the people on your account are senior and focused on search. Check these five things before you sign.

1. Ask how many staff work on SEO, not on the whole agency.
2. Ask who runs your account and how many other accounts that person holds.
3. Ask for two case studies with numbers, units and dates in your industry.
4. Check the Clutch rating and the review count, then read the three lowest reviews.
5. Confirm the minimum term and the notice period in writing.

Red flags when choosing

• Headcount claims that do not match the Clutch employee band.
• Case studies with percentages but no dates or starting numbers.
• A senior team in the pitch and a junior team on the account.
• AI search sold as a feature with no metric behind it.
• Contracts of 12 months or more with no exit clause.

Which large SEO company fits your business

Match the firm to your budget and the services you need. Use this table to build a shortlist of two or three.

What large SEO companies cost in 2026

Five of the eight companies publish a starting price or budget guide. They range from $500 per month for Thrive's local SEO to about $6,000 per month at Victorious.

Only Loopex Digital, Thrive and WebFX state their contract terms. For what each budget tier usually buys, see our SEO pricing guide.

FAQ

Which is the largest SEO company in the world?

On this list, WebFX is the largest by headcount, with 750 staff on its about page and 450 Clutch reviews. It is a full-service agency, so not all of those staff work on SEO. Among SEO-only firms, Loopex Digital has 100+ SEO specialists and SeoProfy has 100+ experts.

Is a bigger SEO company better?

Not always. A bigger company can staff more work at once, but your results depend on the few people assigned to your account. Ask how many specialists will work on your site and how many other accounts they hold. A smaller senior team often beats a large junior one.

How much do large SEO companies cost?

Published entry prices on this list run from $1,500 per month at Loopex Digital to about $6,000 per month at Victorious. WebFX starts at $3,000 per month and SeoProfy at $1,600. Thrive quotes $500 to $10,000+ per month. Three firms price by quote only.

How do you measure the size of an SEO company?

We used two measures. The first is staff headcount, from the Clutch employee band and the agency's own published team count. The second is Clutch review volume, which shows how many clients have rated the firm. We flag cases where the two sources disagree.

Do large SEO companies offer AI search optimization?

Seven of the eight companies here sell an AI search service. Fewer explain how they measure it. Loopex Digital reports citation share, WebFX tracks AI citations in OmniSEO, Victorious reports citation visibility and Thrive reports AI-driven traffic. Ask any vendor which prompts it will track and how often.

What contract terms do large SEO companies require?

Most large SEO companies do not publish a minimum term. On this list, Loopex Digital works month to month and Thrive advertises no long-term contracts. WebFX asks for an initial six-month commitment. Victorious lists a $50,000+ minimum project on Clutch. Get the term and notice period in writing.