# Speech & Audio API: the tools companies use

191 companies on usedby use at least one of the 5 tools in this category with a public customer. Recall leads with 52 companies. Counts are of companies on usedby, not of the whole market. Latest check 2026-10-08: 209 of 217 public lines checked.

> Transcription and audio intelligence APIs for developers

Family: [Engineering & Data](https://www.usedby.ai/tools/category/engineering-data.md)

## Ranking

Public customers count every public line, job-post signals included; ties share a rank.

| Rank | Tool | Public customers | Confirmed | Observed | Signals |
|---|---|---|---|---|---|
| 1 | [Recall](https://www.usedby.ai/tools/recall.md) | 52 | 32 | 20 | 0 |
| 2 | [Assembly AI](https://www.usedby.ai/tools/assembly-ai.md) | 49 | 22 | 27 | 0 |
| 3 | [Deepgram](https://www.usedby.ai/tools/deepgram.md) | 45 | 33 | 12 | 0 |
| 4 | [Cartesia](https://www.usedby.ai/tools/cartesia.md) | 39 | 36 | 3 | 0 |
| 5 | [LiveKit](https://www.usedby.ai/tools/livekit.md) | 32 | 9 | 23 | 0 |

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Source: https://www.usedby.ai/tools/category/speech-audio-api · How we check: https://www.usedby.ai/methodology