AI assistants: the tools companies use

General-purpose AI assistants that people chat with to write, analyze, code and research at work.

121

companies on usedby use a tool of this category

121 companies on usedby use at least one of the 4 tools in this category with a public customer. Claude leads with 88 companies. Then come ChatGPT (44) and Microsoft Copilot (4). 16 companies run two of these tools or more. The most common pair is Claude with ChatGPT (15 companies).Latest check Oct 14, 2026: 77 of 138 public lines checked. Counts are of companies on usedby, not of the whole market: we list a company when a public page shows its AI tools.

Ranked by customers

Companies with a public line for each tool. Job-post signals count and are drawn apart in the proof bar.

AI assistants tools ranked by companies on usedby
#	Tool	Customers
1	Claude	88
2	ChatGPT	44
3	Microsoft Copilot	4
4	Gemini	2
	Genspark	—

16 companies run two of these tools or more. The most common pair is Claude with ChatGPT, at 15 companies.

Claude

Claude is used by 88 companies on usedby, 5 confirmed by a case study, a named quote or a press release. Customers include Figma, Slack, and Carvana. Who uses Claude, ChatGPT vs Claude

Customer page: claude.com. Latest check of 60 of 88 lines: Oct 14, 2026.

ChatGPT

ChatGPT is used by 44 companies on usedby, 0 confirmed by a case study, a named quote or a press release. Customers include Bill & Melinda Gates foundation, Harvard, and Walmart. Who uses ChatGPT, ChatGPT vs Claude

Latest check of 11 of 44 lines: Oct 14, 2026.

Microsoft Copilot

Microsoft Copilot is used by 4 companies on usedby, 0 confirmed by a case study, a named quote or a press release. Customers include WPP, Elastic, and OneTrust. Who uses Microsoft Copilot

Latest check of 4 of 4 lines: Oct 14, 2026.

Gemini

Gemini is used by 2 companies on usedby, 0 confirmed by a case study, a named quote or a press release. Customers include Fivetran and Grafana Labs. Who uses Gemini

Latest check of 2 of 2 lines: Oct 13, 2026.

Newest customers

Companies first listed by a tool of this category in the last 90 days.

No new customer yetTracking of changes on these tools' pages started on October 2, 2026. New customers appear here, dated, after two complete checks of those pages.

Most compared

Side-by-side pages with the companies behind each tool.

Questions about AI assistants

Answers drawn from usedby data.

What is the most used tool in AI assistants?

Claude, used by 88 of the 121 companies on usedby in this category. Then come ChatGPT (44) and Microsoft Copilot (4). Who uses Claude.

Do more companies use Claude or ChatGPT?

Claude: 88 companies on usedby, against 44 for ChatGPT. 15 companies use both, counting every proof level (job posts included).

Do companies use several tools in AI assistants?

Yes: 16 of the 121 companies on usedby in this category run two or more. The most common pair is Claude with ChatGPT (15 companies).

How does usedby rank these tools?

By the number of companies with a public line for each tool, read from dated captures of vendor customer pages, case studies, press releases and job posts. Every proof level counts in the totals and the ranking, job-post signals included (the weakest proof, shown apart in the proof bar); ties go to the stronger proofs. usedby lists a company when a public page shows it, so these counts describe the companies on usedby, not the whole market.