# OpenAI API vs Perplexity: who uses which

On usedby, 37 companies use OpenAI API and 26 use Perplexity. 1 company uses both, including Stripe. Counts include every proof level, job-post signals included; each company keeps its proof level on each side. Latest check 2026-10-18: 58 of 63 public lines checked.

## Side by side

|  | [OpenAI API](https://www.usedby.ai/tools/openai-api.md) | [Perplexity](https://www.usedby.ai/tools/perplexity.md) |
|---|---|---|
| Public customers | 37 | 26 |
| Confirmed | 3 | 12 |
| Observed | 33 | 14 |
| Signals (job posts) | 1 | 0 |
| Top industries of customers (every proof level) | DevTools & Infrastructure (6), Artificial Intelligence (4), Marketplace (4) | Fintech & Payments (5), Investment & VC (4), Data & Analytics (3) |
| Category | Foundation models & model APIs | AI search & research |
| Data processing terms | — | A data processing agreement is available. ([trust.perplexity.ai](https://trust.perplexity.ai/), checked 2026-10-07) |

## Companies that use both

Every proof level counts; the proof level of each side is shown, strongest proofs first. The first public proof is not an adoption date.

| Company | Proof, OpenAI API | Proof, Perplexity | First public proof, OpenAI API | First public proof, Perplexity |
|---|---|---|---|---|
| [Stripe](https://www.usedby.ai/companies/stripe.md) | Observed | Observed | On or before October 2026 | On or before September 2026 |

## Published results

Reviewed stories only; usedby did not measure the figures.

- Perplexity: [IVP](https://www.usedby.ai/case-studies/ivp-perplexity.md): **100%**: “now have a 100% adoption rate of Perplexity” (captured by usedby 2026-10-12)
- Perplexity: [Bessemer Venture Partners](https://www.usedby.ai/case-studies/bessemer-venture-partners-perplexity.md): **50%**: “Cut 50% or more from manual research, document processing, and repetitive spreadsheet tasks” (captured by usedby 2026-10-12)

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Source: https://www.usedby.ai/compare/openai-api-vs-perplexity · How we check: https://www.usedby.ai/methodology