Assembly AI vs Cartesia: who uses which
Customers, public proof and the companies that use both.
On usedby, 49 companies use Assembly AI and 39 use Cartesia. 2 companies use both, including LiveKit and Retell. Assembly AI leads among the Artificial Intelligence companies on usedby that use either tool.Latest check Oct 8, 2026: 86 of 88 public lines checked. Counts include every proof level, job-post signals included. Companies named on both have a confirmed or observed line on each side.
Who uses Assembly AI, Cartesia, or both
Every company with a public proof for at least one of the two tools.
47
use only Assembly AI
2
companies use both
37
use only Cartesia
47 companies use only Assembly AI, 37 use only Cartesia and 2 use both, out of the 86 companies on usedby that use at least one of them.
Where it lands
Newest customers
We have not started tracking changes for Assembly AI yet.
Where it lands
Newest customers
No new customer since tracking started on October 8, 2026.
Who uses both
Companies with a confirmed or observed line on both tools.
| Company |
|---|
 LiveKit |
 Retell |
By industry
Which tool the companies on usedby use, by industry. Shares of the companies on usedby that use Assembly AI, Cartesia or both: a share of the companies on usedby, not of the market.
Assembly AI onlyBothCartesia only
More common with Assembly AI
- Artificial Intelligence12 of the 16 Artificial Intelligence companies on usedby that use either tool use Assembly AI.
- Sales Tech & CRM5 of the 7 Sales Tech & CRM companies on usedby that use either tool use Assembly AI.
- Marketing Tech6 of the 6 Marketing Tech companies on usedby that use either tool use Assembly AI.
Source: confirmed and observed usedby lines. Job-post signals, the weakest proof level, are left out of these shares.
Side by side
Facts from our data and from each vendor's public pages. Each line says where it comes from.
Assembly AI
CartesiaWhat customers report
Results as the vendor or the customer published them, with the source and the date.
Assembly AI
Aloware has seen 50% of its client base convert to its suite of AI-powered packages
Aloware
Vendor case study, assemblyai.com, captured Oct 8, 2026
the 18 million calls it processes a year
EchoAI
Vendor case study, assemblyai.com, captured Oct 8, 2026
Cartesia
Daily Bots delivers voice-to-voice latencies – including transport over the network – as fast as 500ms.
Daily
Vendor case study, cartesia.ai, published Sep 24, 2024
Goodcall achieves a 90 ms on average for time-to-first-audio
Goodcall
Vendor case study, cartesia.ai, published Oct 9, 2024
Questions about Assembly AI and Cartesia
Which is used more, Assembly AI or Cartesia?
Assembly AI has more customers on usedby: 49 against 39 for Cartesia.
Do companies use both Assembly AI and Cartesia?
Yes. 2 companies use both on usedby, including LiveKit and Retell.
Who uses Assembly AI?
49 companies on usedby, each with the public page that shows it. See who uses Assembly AI.
Who uses Cartesia?
39 companies on usedby, each with the public page that shows it. See who uses Cartesia.
How does usedby count customers?
A company counts when a public page shows it: a vendor's customer page, a case study, a press release or a job post, most saved with a dated capture. Every line is a customer, at one of three proof levels: confirmed, observed or signal (a job post, the weakest). A company is named as using both tools when its lines on both are confirmed or observed.