Cartesia

Overview

Cartesia specializes in real-time voice synthesis with some of the lowest latency available. Its Sonic models are built for voice agents and conversational apps where sub-100ms response time matters more than studio polish, and it offers instant voice cloning from about 10 seconds of audio plus emotional-expressiveness controls. It is a credit-metered, developer-centric platform.

Key features

• Sonic real-time TTS
• Sub-100ms latency
• On-device models
• Instant voice cloning
• Emotion controls

Pricing

Cartesia is freemium: a free tier lets you try the core features, and paid plans start at $5/mo. Plans (2026): Free ($0/mo), Pro ($5/mo), Startup ($39/mo), Scale ($239/mo), Enterprise (Custom). Prices change often, so confirm current limits, credits, and enterprise terms on the official site.

Pros

• Among the fastest inference latency (sub-100ms)
• Streaming and on-device Sonic models
• Instant cloning from ~10s of audio
• Emotional-expressiveness controls

Cons

• Newer and less battle-tested
• Developer-first — no polished studio UI
• Free tier is non-commercial

Who should use Cartesia

Developers building phone agents, customer-service bots, and interactive voice apps that need the fastest possible response.

Our verdict

If latency is your bottleneck, Cartesia is hard to beat — Sonic streams speech in real time and clones a voice from seconds of audio. Newer and more API-first than the studio tools, so expect to build rather than click.

Try Cartesia

Ready to try it? Visit the Cartesia official website to create an account and explore its available voices and cloning options.