slug: llm-market-share

category: methodology

value: 150+ leaders

claim: Menlo surveyed more than 150 technical leaders across startups and enterprises for its mid-year model update.

source_title: 2025 Mid-Year LLM Market Update: Foundation Model Landscape + Economics

population: more than 150 technical leaders across startups and enterprises, combined with Menlo Ventures market modeling

denominator: Menlo's modeled enterprise usage or spend market; the public page does not expose a metric-level respondent base for every percentage

period: mid-year 2025; published July 31, 2025

geography: source page does not publish a country weighting for the cited survey

caveat: Menlo is an investor in Anthropic and other AI companies. Its enterprise usage and spend estimates are modeled and are not comparable with consumer web-traffic share.

evidence: Public methodology notes and sections on enterprise usage, open source, switching and compute spend

definition_family: enterprise usage and modeled API spend


claim: Menlo estimated model API spending at $8.4 billion in mid-2025, up from $3.5 billion six months earlier.


claim: Anthropic held 32% of modeled enterprise LLM usage in Menlo's mid-2025 estimate.


claim: OpenAI held 25% of modeled enterprise LLM usage, down from 50% at the end of 2023.


claim: Google held 20% of modeled enterprise LLM usage.


claim: Meta Llama held 9% of modeled enterprise LLM usage.


claim: DeepSeek held 1% of modeled enterprise LLM usage.


claim: Anthropic captured 42% of Menlo's code-generation usage estimate, compared with 21% for OpenAI.


claim: Open-source models powered 13% of surveyed AI workloads, down from 19% six months earlier.


claim: Sixty-six percent of builders upgraded models within their existing provider.


claim: Twenty-three percent of builders did not switch models during the prior year.


claim: Eleven percent of builders switched model vendors during the prior year.


claim: Within one month of Claude 4's release, Sonnet 4 represented 45% of Anthropic users in Menlo's data.


claim: Claude Sonnet 3.5's share among Anthropic users fell from 83% to 16% during that migration.


category: inference

claim: Seventy-four percent of startup builders said the majority of workloads were inference, up from 48% a year earlier.


claim: Forty-nine percent of large enterprises said most or nearly all compute was inference-driven, up from 29%.


claim: Similarweb estimated 5,517,989,010 visits to chatgpt.com in December 2025.

source_title: Winners and Losers in the Gen AI Market

population: estimated monthly web visits to seven named standalone AI domains tracked in the published table

denominator: the individual platform's estimated monthly visits; these source rows are visit counts or source-published growth rates, not market-share percentages

period: January-December 2025; published January 21, 2026

geography: global web traffic estimates

caveat: Web visits measure browser traffic to named domains, not total users, app usage, API consumption, revenue, embedded-product usage, or enterprise spend. Konabayev share calculations use only the seven rows published by Similarweb.

evidence: Published monthly traffic table and 2025 growth summary

definition_family: standalone-domain web traffic


claim: Similarweb estimated 1,735,320,959 visits to gemini.google.com in December 2025.


claim: Similarweb estimated 328,865,716 visits to deepseek.com in December 2025.


claim: Similarweb estimated 271,154,744 visits to grok.com in December 2025.


claim: Similarweb estimated 179,583,644 visits to perplexity.ai in December 2025.


claim: Similarweb estimated 172,690,841 visits to claude.ai in December 2025.


claim: Similarweb estimated 21,559,214 visits to meta.ai in December 2025.


claim: ChatGPT represented 67.07% of December visits across the seven standalone domains in Similarweb's published table.

source_title: Konabayev seven-domain December 2025 web-share calculation

population: the seven standalone AI domains in Similarweb's December 2025 public table

denominator: 8,227,164,128 estimated December visits, equal to the sum of the seven published domain rows

period: December 2025; calculated and audited July 11, 2026

geography: global web traffic estimates inherited from the input source

caveat: Konabayev-derived share of a fixed seven-domain set, not a Similarweb-published share and not total AI usage across apps, APIs, embedded products, or omitted domains.

evidence: domain December visits divided by 8,227,164,128 and rounded to two decimals

research_method: arithmetic derivation from Similarweb's seven published December visit rows

derivation: platform December visits / sum of seven December visit rows


claim: Gemini represented 21.09% of December visits across the seven standalone domains in Similarweb's published table.


claim: DeepSeek represented 4.00% of December visits across the seven standalone domains in Similarweb's published table.


claim: Grok represented 3.30% of December visits across the seven standalone domains in Similarweb's published table.


claim: Perplexity represented 2.18% of December visits across the seven standalone domains in Similarweb's published table.


claim: Claude represented 2.10% of December visits across the seven standalone domains in Similarweb's published table.


claim: Meta AI represented 0.26% of December visits across the seven standalone domains in Similarweb's published table.


claim: Similarweb reported 548% growth in Gemini web visits from January to December 2025.


claim: Similarweb reported 125% growth in Claude web visits from January to December 2025.


claim: Similarweb reported 80% growth in Perplexity web visits from January to December 2025.


claim: Similarweb reported 43% growth in ChatGPT web visits from January to December 2025.