Which legal AI startup is growing the fastest?

Which legal AI startup is growing the fastest?

Why is legal AI growing so fast right now?

Legal AI is growing really fast now because law firms and corporate legal teams have moved from testing generative AI to using it in daily work, while clients are starting to demand the productivity gains themselves.

Thomson Reuters' 2026 research captures the change well. Some 41% of law firms now say they actively use generative AI, up from 28% a year earlier. Corporate legal departments moved even faster, from 23% to 47%. Among professionals more broadly, 74% use AI several times a week.

The pressure is no longer coming only from lawyers who want better tools. Thomson Reuters found that 32% of in-house legal professionals had already reconsidered, or expected to reconsider, relationships with firms that failed to show clear AI-enabled value. Another 71% expect outside law firms to change how they charge as AI use increases.

That pressure has become more visible lately. The Financial Times reported that Morgan Stanley, Citigroup and Goldman Sachs are pushing large law firms to show how AI is reducing costs, with some clients asking for competitive bids, fixed fees or evidence of actual productivity gains. Almost half of large firms in a Citi survey were already seeing some effect on pricing.

This is a much stronger growth environment than legal AI startups faced two years ago. Inside many firms, the question has shifted from whether lawyers should be allowed to use generative AI to which approved system should sit inside the workflow.

What does “fastest-growing legal AI startup” actually mean?

For this comparison, we treat the fastest-growing legal AI startup as the company increasing paid, recurring usage fastest once the business is already large enough for the growth to be meaningful.

Percentage growth alone gives strange answers. A startup going from $1 million to $10 million of annual recurring revenue grew 10x. A company going from $200 million to $350 million grew far less in percentage terms but added fifteen times as much revenue.

Customer counts can be equally deceptive. A platform serving thousands of small practices can have more customers than one deployed across huge international firms, while generating far less revenue. Funding is even less useful: a new valuation tells us what investors expect, not how much lawyers are actually paying.

We therefore give the most weight to recurring revenue growth at meaningful scale. We then check how much revenue the company added in dollars, how quickly customers and users are increasing, whether people keep using the product after rollout, and whether existing accounts are expanding.

That definition makes the race much tighter. Harvey leads on size and dollars added. Legora leads on percentage growth among the companies that have already reached serious scale.

Which legal AI startups are actually in the race today?

Harvey and Legora are currently the two legal AI startups with the strongest combination of nine-figure revenue, large enterprise deployments and rapid growth, while Spellbook is the clearest challenger from below.

Several smaller companies deserve attention because they are growing extremely quickly in specific parts of legal work. GC AI focuses on in-house teams. Eve and Supio are expanding inside plaintiff law. Solve Intelligence has built a strong position around patents and intellectual property.

We would separate those companies from businesses with very different economics. Darrow, for example, helps firms find litigation opportunities. Crosby operates more like an AI-native law firm. Both can grow very quickly without being directly comparable with subscription platforms such as Harvey or Legora.

We would also keep Thomson Reuters, LexisNexis and Clio outside the startup ranking. Their products matter enormously to the competitive environment, but they are established legal technology businesses rather than AI-native startups fighting to create a new category.

Company	Latest useful scale measure	Customer reach	Main position
Harvey	More than $350M annualized revenue	2,400+ customers	Large firms and enterprise legal
Legora	About $150M ARR by current estimates	1,500+ organizations	Large firms and enterprise legal
Spellbook	Targeting roughly $100M ARR by year-end	4,500+ legal teams	Contracts and in-house legal
GC AI	Revenue undisclosed	2,100+ legal teams	In-house legal
Eve	Revenue undisclosed	1,000+ plaintiff firms	Plaintiff law
Solve Intelligence	Revenue in the millions	700+ IP teams	Patents and IP

If you want more recent data on this point, please see our latest Legal Tech market report.

Is Harvey still the biggest legal AI startup today?

Harvey is still clearly the biggest AI-native legal software startup today by disclosed revenue, professional usage and high-end enterprise reach.

Recent reporting puts Harvey above $350 million in annual recurring or annualized revenue, up from roughly $190 million at the start of the year. Legora's best current estimates sit around $150 million, while Spellbook is aiming to reach approximately $100 million by the end of the year.

Harvey's customer footprint has also become much larger. The company went from 40 customers at the end of 2023 to 235 at the end of 2024 and more than 500 by August 2025. Harvey's current website lists more than 2,400 customers across over 70 countries.

More than 200,000 lawyers now use the platform. Harvey also says more than 75 Am Law 100 firms are customers, giving it unusually deep access to the highest-spending part of the legal market.

Recent customer announcements show that the expansion is continuing rather than relying on old wins. Harvey has lately announced deployments or expanded rollouts with GE Aerospace, Jackson Lewis, Finnegan, Nelson Mullins, Macpherson Kelley and Grupo Financiero Inbursa.

Legora is catching up very quickly, but Harvey still enters this race with more than twice the revenue and a considerably larger installed professional base.

Is Legora growing faster than Harvey right now?

Legora is currently growing faster than Harvey in percentage terms, which gives Legora the strongest claim to being the fastest-growing major legal AI startup.

Legora publicly crossed $100 million ARR less than 18 months after moving past $1 million. Independent estimates from Sacra and Dealroom then put the company around $150 million in the second quarter, roughly 50% higher in one quarter.

The longer comparison is even more striking. Sacra estimates Legora finished 2025 around $50 million ARR. Moving from approximately $50 million to $150 million means the business roughly tripled in about half a year.

Harvey started from a much bigger base. Recent reporting puts its annualized revenue around $190 million at the start of the year and above $350 million lately. That works out to growth of more than 80%.

An 80%-plus increase at Harvey's size is exceptional. Legora's roughly 200% increase is still much faster.

The customer trajectory points the same way. Legora had 250 customers in May 2025, more than 400 in October, over 1,000 when it announced the $100 million milestone and more than 1,500 today.

Growth measure	Harvey	Legora
Approx. starting revenue base	~$190M	~$50M
Latest revenue level	$350M+	~$150M
Approx. relative increase	80%+	~200%
Current customer scale	2,400+	1,500+
Winner on percentage growth		Legora

If you want more recent data on this point, please see our latest Legal Tech market report.

Who is adding more legal AI revenue: Harvey or Legora?

Harvey is adding more legal AI revenue in actual dollars than Legora, even though Legora is multiplying faster.

Moving from roughly $190 million to more than $350 million means Harvey added over $160 million of annualized revenue during the current growth stretch.

Legora's estimated move from about $50 million to roughly $150 million added around $100 million.

The difference stops the percentage comparison from becoming misleading. Legora has grown about threefold, but Harvey created a larger amount of new recurring business while starting from a much higher level.

Harvey's earlier trajectory makes the point even clearer. The company first announced more than $100 million ARR in August 2025. In roughly a year, it has added well over $200 million on top of that base.

Very few startups ever reach $200 million of recurring revenue. Harvey has recently added more than that amount while continuing to expand.

So if someone asks which legal AI startup is absorbing the greatest amount of new spending today, Harvey has the better answer.

Which legal AI startup is signing customers fastest right now?

Legora appears to have the fastest percentage growth in enterprise customers today, while Harvey is still landing more large organizations and Spellbook has built the broadest overall customer count.

Legora's expansion is unusually easy to track. The company moved from 250 customers in May 2025 to more than 400 five months later, passed 1,000 in early 2026 and now serves over 1,500 organizations.

That growth has also spread geographically. Legora went from roughly 20 markets to more than 50 while opening across North America, Asia-Pacific and Latin America. The United States became its largest individual revenue market within roughly a year of launch there.

Harvey's customer base remains larger, but its recent announcements tell us more than repeating the total. The company has been adding large law firms and enterprise legal departments almost every week lately, including firmwide deployments and major corporate accounts.

Spellbook approaches the market differently. More than 4,500 legal teams use the product across over 80 countries, giving it more customer organizations than either enterprise leader. Its Word-based contract workflow makes adoption easier for smaller firms and in-house teams that would struggle to justify a broad platform rollout.

These companies are winning customers through different doors. Legora has the steepest enterprise growth curve, Harvey keeps collecting large accounts, and Spellbook reaches much further into the fragmented middle of the legal market.

Are lawyers actually using Harvey and Legora after their firms buy them?

Harvey and Legora are both seeing heavy real-world usage after deployment, which makes their growth much more convincing than a pile of signed enterprise contracts.

Harvey currently reports around 850,000 queries a day and more than 50 million files processed daily. An independent RSGI study commissioned by Harvey found an average monthly usage rate of 92% across the customers it examined.

The historical change is striking. In August 2025, Harvey said weekly active users had risen fourfold in a year, monthly queries had increased 5.5x and active files stored on the platform had jumped from 268,000 to 9.75 million.

Legora has published similarly strong customer-level numbers. At Norwegian firm BAHR, around 80% of staff were active users and as many as 30% used Legora more than ten times a day. Forvis Mazars in Germany reported daily usage above 80% among licensed lawyers during its rollout.

Those are unusually high numbers for enterprise software bought by law firms. Lawyers have historically been difficult users to move away from email, Word and established research systems.

We can rule out one easy explanation for the growth race: Harvey and Legora are not simply selling expensive licenses that firms then forget about. Where usage has been disclosed, lawyers are actually changing their routines.

Is Legora reaching $100 million ARR in 18 months really that unusual?

Legora's jump from $1 million to $100 million ARR in 18 months is genuinely abnormal, even by the standards of today's fastest-growing enterprise AI companies.

Bessemer Venture Partners compared Legora with other major software and AI companies in its portfolio research and found that Legora reached the $100 million milestone faster than every enterprise company in the comparison, including several businesses famous for extreme early growth.

We should treat a venture investor's comparison with some caution, but the underlying revenue milestone comes from Legora itself. The difficult part is the combination of speed and customer type.

Selling enterprise legal software usually involves security reviews, procurement, data-governance checks, integrations and internal approval from firms that handle extremely sensitive information. Legora did not reach $100 million by selling a $20 consumer subscription.

The company also kept growing after crossing the milestone. Current independent estimates suggest another 50% increase during the following quarter.

That gets rid of one common problem with “fastest-growing startup” stories. Legora has already moved beyond the tiny revenue base where one or two contracts can produce a spectacular growth percentage.

Is Harvey's growth actually harder because Harvey is already so big?

Harvey's current growth is arguably harder to reproduce than Legora's because Harvey is still growing at an extreme rate from a business already measured in hundreds of millions of dollars.

The arithmetic gets brutal as a software company gets bigger. Doubling $20 million requires another $20 million. Doubling $200 million requires another $200 million of annual business, along with the sales, implementation, support and infrastructure needed to serve those customers.

Harvey has remained close to that kind of pace anyway.

The company had 350 employees when it announced more than $100 million ARR in August 2025. Recent reporting puts headcount around 1,200. Its reach has expanded from 54 countries to more than 70, while the product itself has spread from research and drafting into agents, institutional knowledge, document processing, collaboration and broader legal workflows.

Harvey has also been shipping quickly lately. Harvey II added longer-lived matter context and memory, while Harvey Tenet marked the company's move into its own post-trained open-weight model. That work reduces the risk that Harvey remains only a wrapper around someone else's frontier model.

Legora still wins the percentage-growth comparison. Harvey deserves more credit than that single percentage suggests because it is trying to maintain startup growth with a much heavier business behind it.

Is Spellbook the sleeper in the legal AI race?

Spellbook is the clearest sleeper in legal AI today because its customer reach is already enormous and its contract-focused product can spread through parts of the market that Harvey and Legora serve less efficiently.

Spellbook says more than 4,500 legal teams across over 80 countries use its software. The company tripled revenue in 2025 and is now targeting roughly $100 million ARR by year-end.

Its expansion inside existing customers also looks healthy. Spellbook says net revenue retention has stayed above 130%, meaning the average cohort spends materially more with the company over time.

The distribution model explains part of that growth. Spellbook started directly inside Microsoft Word, where lawyers already draft and redline contracts. A small legal team can adopt the tool without making the kind of firmwide technology decision required for a large Harvey or Legora deployment.

One recent detail is especially interesting. Spellbook's CEO said weekly lawyer signups almost doubled after Anthropic pushed Claude further into legal work. General-purpose AI apparently introduced more lawyers to the category, and some of them then looked for something built specifically around contracts.

Spellbook still lacks the disclosed current revenue needed to put it ahead of Legora on growth. But a company with thousands of customers, 130%-plus retention and a plausible route toward nine-figure ARR can no longer be treated as a minor player.

If you want more recent data on this point, please see our latest Legal Tech market report.

Are smaller legal AI startups growing even faster than Legora?

Supio, Solve Intelligence and GC AI are growing faster than Legora on some early-stage measures, but none has yet shown the same combination of extreme growth and nine-figure revenue.

Supio says its ARR has increased 17x since the plaintiff-law platform emerged from stealth less than two years ago. The company also said its customer base more than doubled during the first half of 2026.

Solve Intelligence has produced a similarly steep curve in patent work. In April 2025, TechCrunch reported that around 200 IP teams used the product and that revenue was growing about 25% month over month. Solve now says more than 700 IP teams use the platform across six continents.

GC AI has expanded to more than 2,100 in-house legal teams. Its narrow focus on corporate lawyers gives it a clear route into a customer group that is adopting generative AI particularly quickly.

Eve has gone deep into another specialist market. The company says more than 1,000 plaintiff firms now use its platform across over 200,000 active cases.

These are real challengers, and one may eventually outrun both leaders. The missing piece today is comparable revenue disclosure.

Startup	Recent growth evidence	Why we do not rank it first yet
Supio	17× ARR since stealth; customers more than doubled in H1	Absolute ARR undisclosed
Solve Intelligence	200 to 700+ IP teams in roughly a year	Much smaller revenue base
GC AI	2,100+ in-house legal teams	Current revenue undisclosed
Eve	1,000+ firms; 200,000+ active cases	Current revenue undisclosed
Legora	Nine-figure ARR plus rapid customer growth	Already large enough for the percentage to be meaningful

Who is winning Big Law right now: Harvey or Legora?

Harvey is still winning Big Law today, although Legora has become a serious enough competitor that firms can no longer treat Harvey as the automatic legal AI choice.

Harvey says more than 75 Am Law 100 firms now use the platform. Recent rollouts include Jackson Lewis across more than 1,100 attorneys, along with deployments at firms such as Finnegan, Nelson Mullins and Davis Wright Tremaine.

The deeper advantage comes from how Harvey is being embedded. Customers are building custom agents, connecting internal knowledge and using Harvey across research, drafting, review and matter workflows. Willkie, for example, integrated Harvey with its own proprietary AI environment rather than treating the product as a separate chatbot.

Legora is winning many of the same type of customers. White & Case, Cleary Gottlieb, Goodwin, Linklaters, Dentons and other international firms are on its platform. Legora has also expanded aggressively outside its Nordic base, with offices across major US legal markets and newer operations in Japan, Singapore, South Korea and Mexico.

That geographical push has already changed the business: the United States became Legora's largest individual revenue market.

Harvey still has the stronger Big Law position because it combines a larger installed base with more revenue and wider penetration of the Am Law 100. Legora is closing ground quickly enough that the next round of firmwide platform decisions should be much more competitive.

Who is winning legal AI inside corporate legal departments?

No startup has locked up in-house legal AI today; Harvey leads at the high end, while GC AI and Spellbook have built strong ways into smaller and mid-sized legal teams.

Harvey has been adding large corporate deployments alongside its law-firm business. Its customer base includes major global companies, and recent announcements such as GE Aerospace and Grupo Financiero Inbursa show that enterprise legal departments remain a major part of the expansion.

Legora is moving in the same direction with customers including Barclays and other large international companies. Its integrations with Box, Intapp, NetDocuments and DeepJudge make more sense when we view Legora as a platform that wants to sit across an organization's legal data rather than remain a standalone drafting tool.

GC AI takes a much narrower route. It was built specifically for in-house counsel and now says more than 2,100 legal teams use the platform for contracts, policies, compliance work and company-specific legal questions.

Spellbook attacks many of those teams through contract work. The company says in-house legal departments have been its fastest-adopting customer group, helped by the fact that those teams usually care about reducing workload rather than preserving billable hours.

The in-house market looks more open than Big Law. Harvey has the biggest enterprise accounts, but GC AI and Spellbook can reach thousands of teams without winning a giant organization-wide platform decision first.

Could OpenAI, Anthropic or Google crush Harvey and Legora?

OpenAI, Anthropic and Google can put real pressure on legal AI startups, but their latest moves are also making the market bigger and creating new distribution channels for Harvey, Legora and Spellbook.

The threat has become much more concrete lately. OpenAI is preparing a deeper push into legal workflows, including connections between ChatGPT and specialist legal software. Anthropic has expanded Claude's legal capabilities. Google recently launched Gemini Enterprise for Legal.

A raw model provider can absorb features that once looked distinctive. Research, document comparison, drafting and contract review will keep becoming cheaper and easier to reproduce.

Harvey and Legora have responded by moving higher up the stack. Harvey now handles institutional knowledge, agents, shared workspaces, large-scale document processing and integrations, while also developing its own model work through Harvey Tenet.

Legora has taken a particularly aggressive integration approach lately. It has announced work with NetDocuments, Intapp, Box, DeepJudge and Avvoka, and Google selected Legora as a partner for Gemini Enterprise for Legal. Legora also acquired Wexler to add fact intelligence.

Google can compete with Legora at the model and application level while distributing Legora through another product at the same time. Strange market, but that's where legal AI is heading.

Spellbook has already seen the same dynamic from the bottom up: Claude's legal launch drove more lawyer signups rather than fewer.

Frontier AI companies will probably make individual legal AI features less valuable. The startups can still grow if they own the workflow, permissions, knowledge, integrations and day-to-day user relationship around those models.

If you want more recent data on this point, please see our latest Legal Tech market report.

Will Big Law building its own AI slow Harvey and Legora?

Big Law's push into bespoke AI will limit how much of the legal workflow Harvey or Legora can own, but it has not slowed either company's growth so far.

The Financial Times recently reported that around one-fifth of large law firms are personalizing or building AI technology. Kirkland & Ellis has committed about $500 million to its own technology effort, while Freshfields is working directly with Anthropic on specialized legal AI.

Those firms have a good reason to build. A top law firm's proprietary work product, precedents, client history and internal legal judgment can be far more valuable than another generic drafting feature.

Yet “building AI” rarely means building everything. Willkie's approach is a good example: the firm has its own proprietary system and still integrates Harvey inside it. Other firms combine commercial AI, internal tools, legal databases and multiple foundation models.

Legora is also designing for that world. Its recent integrations let firms bring institutional knowledge and external systems into the same working environment.

The real risk to Harvey and Legora would come if large firms decided they could reproduce the whole product cheaply with a frontier model and their own engineering team. We have little evidence of that happening at scale today.

For now, the firms spending most aggressively on bespoke AI are often the same firms buying specialist platforms.

Which legal AI startup has the best growth, not just the fastest growth?

Harvey currently has the highest-quality growth in legal AI because revenue, customer size, usage and product depth are all expanding together, while Legora still has the faster growth rate.

Harvey's 92% average monthly usage across the customers studied by RSGI is particularly useful here. It suggests that the company is not depending on procurement teams buying thousands of licenses that lawyers barely touch.

Legora also looks strong on this measure. Its disclosed deployments at BAHR and Forvis Mazars show unusually heavy day-to-day use, while the company has continued expanding within large firms after the initial sale.

Spellbook adds another good benchmark with net revenue retention above 130%. Existing accounts are spending more, which is generally healthier than depending entirely on a constant stream of new customer acquisition.

Investors are pricing that growth very aggressively. Harvey's last company-announced financing valued it at $11 billion, while more recent market data put a subsequent financing around $15.5 billion. Legora was valued around $5.6 billion in its last completed major round and has lately been discussing funding at more than $10 billion according to the Financial Times and other reports.

Those valuations have risen faster than the businesses themselves. We would avoid using them as evidence that either company is winning. They show how much future growth investors already expect.

On the operating numbers we can actually observe, Harvey has the more proven growth engine. Legora has the steeper one.

Which legal AI startup is growing the fastest?

Legora is the fastest-growing major legal AI startup today, while Harvey remains the bigger company and is adding more business in actual dollars.

The distinction survives every useful way we tried to test it.

Legora reached $100 million ARR only 18 months after passing $1 million. Current estimates suggest the business then grew another 50% in a single quarter. Its customer base rose from 250 in May 2025 to more than 1,500 today, while usage has spread to more than 100,000 legal professionals across over 50 markets.

That is enough scale for the percentage growth to count. Supio, Solve Intelligence and other younger companies can show even larger multiples in selected periods, but they are still working from much smaller or undisclosed revenue bases.

Harvey wins the other half of the argument. As seen above, Harvey is already above roughly $350 million in annualized revenue, versus a best current estimate near $150 million for Legora. Harvey has also added more revenue dollars during the current growth stretch and remains considerably stronger in Big Law.

The fresh evidence makes the conclusion stronger rather than weaker. Harvey is still announcing major deployments almost weekly. Legora is continuing to add customers, countries, integrations and acquisitions at unusual speed. At the same time, OpenAI, Google and Anthropic are moving deeper into legal work and large firms are building more of their own technology, so neither company has an easy road ahead.

If we have to put one name under “fastest-growing legal AI startup,” we would choose Legora today.

If the question changes to “which legal AI startup is winning the market?”, Harvey still has the better answer.

If you want more recent data on this point, please see our latest Legal Tech market report.

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