Company lists · Data refreshed September 2026

Top 22 Llm development platforms based in San Francisco, United States

RevenueBase identified 43 llm development platforms headquartered in San Francisco, United States as of September 2026 and tracks 1,120 professional contacts across them, including 435 with verified work emails and 361 with mobile numbers. Across the United States, San Francisco is the largest hub for this category.

This list covers llm development platforms headquartered in San Francisco, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 12, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 12, 2026 86% judged on-target in blind review
43Companies
1,120Contacts tracked
435Verified emails
361Mobile numbers
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The 22 largest llm development platforms based in San Francisco, United States

Ranked by team size
Top 22 of 43 llm development platforms based in San Francisco, United States, ranked by team size, largest first. Data refreshed Sep 12, 2026. RevenueBase Smart Search rates how each company's information relates to llm development platforms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 2026201-500357 contacts →

Partial evidence

“Weights & Biases: the AI developer platform.”

Source: RevenueBase Database · checked Sep 12, 2026
2Strong evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202651-200159 contacts →

Strong evidence

“The AI engineering platform for teams shipping reliable AI agents and LLM applications.”

Source: RevenueBase Database · checked Sep 12, 2026
3Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202611-50126 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 12, 2026
4Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202651-20084 contacts →

Indirect evidence

“Exa is an applied AI research lab organizing human knowledge, starting with the web.”

Source: RevenueBase Database · checked Sep 12, 2026
5Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202651-20064 contacts →

Indirect evidence

“Smallest.ai is an AI research lab pioneering the future of compact, powerful models.”

Source: RevenueBase Database · checked Sep 12, 2026
6Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202611-5035 contacts →

Indirect evidence

“World-class performance per parameter language models, from IoT to the data center.”

Source: RevenueBase Database · checked Sep 12, 2026
7Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202611-5032 contacts →

Indirect evidence

“Run machine learning models in the cloud”

Source: RevenueBase Database · checked Sep 12, 2026
8Partial evidenceSan Francisco, United StatesHQ checked Sep 12, 202611-5029 contacts →

Partial evidence

“Essential AI is on a mission to make frontier AI more accessible through an open, collaborative platform.”

Source: RevenueBase Database · checked Sep 12, 2026
9Partial evidenceSan Francisco, United StatesHQ checked Sep 12, 202611-5015 contacts →

Partial evidence

“Langfuse is an open source AI engineering platform.”

Source: RevenueBase Database · checked Sep 12, 2026
10Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-1012 contacts →

Partial evidence

“Athina helps LLM developers prototype, experiment, evaluate and monitor production-grade AI pipelines.”

Source: RevenueBase Database · checked Sep 12, 2026
11Strong evidenceSan Francisco, United StatesHQ checked Sep 12, 202611-509 contacts →

Strong evidence

“DataNeuron aims to accelerate and scale the development of LLMs by providing a data-centric, end-to-end platform to automate data curation, fine-tuning, inferencing, and model…”

Source: RevenueBase Database · checked Sep 12, 2026
12Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-109 contacts →

Partial evidence

“Making it easy to run or deploy machine learning models and develop LLM applications.”

Source: RevenueBase Database · checked Sep 12, 2026
13Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-108 contacts →

Partial evidence

“Buster gives developers everything they need to train LLMs to write accurate SQL queries for their database.”

Source: RevenueBase Database · checked Sep 12, 2026
14Strong evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-108 contacts →

Strong evidence

“Generate, annotate, clean and enrich datasets for all your AI needs with Refuel's LLM-powered platform.”

Source: RevenueBase Database · checked Sep 12, 2026
15Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-106 contacts →

Partial evidence

“DeepStructure makes AI development as straightforward as web development.”

Source: RevenueBase Database · checked Sep 12, 2026
16Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-106 contacts →

Partial evidence

“Pointable enables teams to quickly build accurate and reliable LLM-native products.”

Source: RevenueBase Database · checked Sep 12, 2026
17Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-106 contacts →

Partial evidence

“Build LLM Apps in minutes, not days.”

Source: RevenueBase Database · checked Sep 12, 2026
18Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-105 contacts →

Indirect evidence

“Okareo helps enterprises ship reliable Voice AI.”

Source: RevenueBase Database · checked Sep 12, 2026
19Strong evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202611-504 contacts →

Strong evidence

“The complete LLM platform with a superior developer experience and robust infrastructure.”

Source: RevenueBase Database · checked Sep 12, 2026
20Strong evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 202611-501 contacts →

Strong evidence

“Enterprise LLM-ops platform to build, observe and protect GenAI apps.”

Source: RevenueBase Database · checked Sep 12, 2026
21Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-101 contacts →

Partial evidence

“Phronema LLC is a private software and research company that develops software and consumer-facing applications, conducts applied research on large language models (LLMs), and…”

Source: RevenueBase Database · checked Sep 12, 2026
22Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 12, 20261-101 contacts →

Partial evidence

“At PropulsionAI, we’re on a mission to redefine the AI model training landscape by providing AI developers with an advanced platform that's not just powerful but also…”

Source: RevenueBase Database · checked Sep 12, 2026

Showing 22 of 43 llm development platforms based in San Francisco, United States

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Llm development platforms based in San Francisco, United States at a glance

As of Sep 12, 2026
38.8%Verified-email coverage
32.2%Mobile-number coverage
26.0Average contacts per company
1-10Median size (employees)
Sep 12, 2026Page data refreshed

Companies by employee count

1-10
26
11-50
13
51-200
3
201-500
1

Freshness & accuracy

How recently the business emails were verified and the company information checked

Email last verified

Median 15.0d

Company record updated

Median 44.0d

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among llm development platforms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in San Francisco, United States whose own description of what they do matches “llm development platforms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names llm development platforms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among llm development platforms, and records with no verified work email. Companies headquartered outside San Francisco are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 435 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 12, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names llm development platforms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many llm development platforms are there based in San Francisco, United States?

RevenueBase identified 43 llm development platforms headquartered in San Francisco, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Weights & Biases, headquartered in San Francisco, tops this list with the largest team on record.

Which city in the United States has the most llm development platforms?

San Francisco leads the United States with 40 headquartered companies, followed by New York (11) and Seattle (6).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 435 verified decision-maker contacts tracked across these 43 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 12, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.