Which ATS Do Companies Actually Use? Data from 13,000+ Employers

We mapped 13,000+ companies to their ATS. Greenhouse leads at 45%, SmartRecruiters 27%, Ashby 12%, Workday 10%.

Max Ascolani28 May 20264 min read

G2 lists over 400 products in the applicant tracking system category. The ATS market is projected to reach somewhere between $5 billion and $35 billion by decade's end, depending on which analyst gets cited. Conference panels debate the merits of each platform as though the market were wide open.

The data tells a simpler story. Four platforms account for 94% of the job listings across 400,000+ postings and 13,000+ employers in Nox's dataset.

The Big Four

Platform	Listings	Share
Greenhouse	181,775	45.3%
SmartRecruiters	107,341	26.8%
Ashby	49,116	12.2%
Workday	41,164	10.3%

The remaining 5.4% is distributed across 15 other platforms, none individually exceeding 2%. Lever, Recruitee, Teamtailor, JazzHR, Rippling, and Workable are among them.

Greenhouse: The Incumbent Standard (45.3%)

Greenhouse launched in 2012 with a thesis that recruiting should be treated as a structured, measurable process. That positioning resonated with the generation of startups that grew into major employers between 2015 and 2022.

The customer base tells the story: HubSpot, Anthropic, Duolingo, the NFL. G2 has ranked it the top ATS consistently through 2025-2026, with 88% of users recommending the product. One estimate puts the customer count at 11,529 verified companies, with another reaching 25,010 when including smaller deployments.

The size distribution is revealing: 41.6% of Greenhouse customers have fewer than 100 employees, 44.7% have 101-1,000, 12.6% have 1,001-10,000, and just 1.1% exceed 10,000. It is predominantly a mid-market tool that expanded upward into enterprise, not the other way around.

SmartRecruiters: The Enterprise Workhorse (26.8%)

SmartRecruiters' customer profile differs meaningfully from Greenhouse's: more enterprise, more global, more industry-diverse. Its approximately 7,044 customers are fewer than Greenhouse's, but they tend to be larger organizations posting more roles each.

The most significant recent development is SAP's acquisition of SmartRecruiters in September 2025, integrating the platform into SAP SuccessFactors' talent management suite. That acquisition repositions SmartRecruiters from a standalone ATS to a module within SAP's enterprise ecosystem -- removing an independent player and creating a tighter SAP-vs-Workday dynamic at the enterprise tier.

Ashby: The Insurgent (12.2%)

Ashby is the most interesting growth story in the dataset. Founded in 2018, it was relatively obscure as recently as 2022. Its Series B came at $21.5 million in late 2022. By June 2024, after 6x revenue growth, it raised a $30 million Series C. In July 2025, it closed a $50 million Series D, bringing total funding to $128 million.

The customer base has grown to over 1,300 organizations, including Reddit, Quora, Vanta, and Ironclad. These are not scrappy seed-stage companies. They are established tech businesses that chose Ashby over Greenhouse.

Ashby's thesis: the ATS category has been under-built. Most systems store data but do not analyze it. Ashby treats recruiting analytics as a first-class feature. The Y Combinator pipeline has been a powerful growth engine -- Ashby has become the default for a significant share of YC startups, accumulating the next generation of scale-ups the same way Greenhouse accumulated the 2015-era cohort.

If current growth rates hold, Ashby is positioned to challenge Greenhouse for the top spot among technology companies within two to three years.

Workday: The Enterprise Ceiling (10.3%)

Workday is not an ATS company. It is an enterprise cloud ERP provider whose recruiting module is one component of a broader HCM suite. Companies adopt Workday Recruiting because they already run Workday for everything else.

With approximately 25,811 customers in the ATS segment, it has more customers than any other platform in the dataset. But many post relatively few roles, and its listing volume per company is lower than venture-backed growth companies on Greenhouse and Ashby.

For job seekers, the Workday distinction matters practically: applying to a Workday-powered career site means longer forms, more complex UX, and often creating an account with the company's Workday instance.

The Long Tail

Beyond the Big Four, the remaining 15 platforms share 5.4% of listings.

Lever was once Greenhouse's primary mid-market competitor. Its share has declined as Ashby captured the growth-stage segment Lever historically served.

Recruitee has carved a niche among European SMBs with lightweight tooling and competitive pricing.

Teamtailor is popular in Scandinavia and increasingly across Europe, focused on employer branding and career site design.

Rippling is primarily a payroll and HR platform that added an ATS module as part of its compound startup strategy. Its listing volume is growing but still modest (88 companies in the dataset).

What This Means for Candidates

The concentration has practical implications.

The application experience is determined by four platforms. Learning the quirks of Greenhouse, SmartRecruiters, Ashby, and Workday covers 94% of application interfaces. Greenhouse and Ashby tend toward shorter, mobile-friendly forms. SmartRecruiters varies by configuration. Workday is consistently the most cumbersome.

ATS choice is a rough company proxy. Greenhouse: mid-market tech. SmartRecruiters: large enterprise or global organization. Ashby: high-growth startup. Workday: Fortune 500.

ATS correlates with hiring velocity. Greenhouse and Ashby companies tend to be in active growth mode and move faster. Workday and SmartRecruiters companies tend to have longer, more structured cycles with more approval layers.

Four hundred vendors compete in the ATS category. Four of them control 94% of the listings. The market is not the wide-open landscape that vendor marketing describes. It is an oligopoly with a fast-growing insurgent.

Sources

Nox monitors job listings across 19 ATS platforms, giving job seekers access to 400,000+ opportunities from 13,000+ employers. Try Nox free -- no credit card required.