AssemblyAI vs Cartesia — Pricing, Plans, and Verified Costs (2026)
AssemblyAI starts at Free. Cartesia starts at $5/mo. AssemblyAI is $5/mo cheaper on the entry tier than Cartesia.
See price history: AssemblyAI · Cartesia
How pricing works
These two tools don't price the same way, so the headline numbers below aren't directly comparable until you plug in your own volume.
- AssemblyAI (Per Usage) — AssemblyAI bills purely on usage. There is no fixed per-seat fee, so the monthly cost depends entirely on how much you consume.
- Cartesia (Hybrid) — Cartesia is hybrid: a fixed subscription from $5/mo plus metered usage on top. Your real bill moves with volume, not seat count.
Per-minute, per-credit and per-token rates exclude any downstream model, speech or telephony costs unless the vendor states otherwise.
Speech AI platform for developers — long-form audio transcription, speaker diarization, and Universal-2 speech understanding models. Usage-based pricing: Best model at $0.37/hr audio, Nano tier at $0.12/hr. Pay-as-you-go with $50 free credit. Popular with podcast platforms, meeting recorders, and companies building on top of long-form audio.
Voice AI research lab building state-of-the-art speech synthesis models (Sonic) with ultra-low latency (<100ms). Usage-based pricing: pay-per-character generation, entry rate around $0.017/1K characters. Enterprise custom for volume. Popular with voice agent developers who need faster-than-ElevenLabs synthesis for real-time conversations.
All plans compared
| Tier role | Plan | AssemblyAI monthly | AssemblyAI annual | Cartesia monthly | Cartesia annual |
|---|---|---|---|---|---|
| Free / starter | Pay-as-you-go: Universal-2 (async) / Free | Free | Free | Free | Free |
| Entry paid | — / Pro | — | — | $5 | $4 |
| Mid tier | — / Startup | — | — | $49 | $39 |
| Pro / power | — / Scale | — | — | $239 | $239 |
| Enterprise | Enterprise | Custom | Custom | Custom | Custom |
Tier names differ across vendors. Rows are aligned by tier role, not name. Full tier structures on each tool's page.
What each is best for
AssemblyAI is worth it if… developers processing long-form audio at scale — podcasts, recorded meetings, call recordings. The per-hour pricing works out cheaper than Deepgram for batch transcription (as opposed to real-time streaming).
Cartesia is worth it if… developers building real-time voice agents where sub-100ms TTS latency matters (voice interruption handling, conversational feel). Sonic model is competitive with ElevenLabs on quality and faster on latency.
Bottom line: Choose based on how you want to pay — AssemblyAI is per usage, Cartesia is hybrid.
Choose AssemblyAI over Cartesia if…
Choose AssemblyAI if…
- You want to pay only for actual usage (per usage, a free entry tier).
- You match the profile AssemblyAI is built for: developers processing long-form audio at scale — podcasts, recorded meetings, call recordings.
- You need a general-purpose voice agents & speech/audio option rather than a vertical-specific one.
Choose Cartesia if…
- You're fine with a base subscription plus metered usage on top (from $5/mo).
- You match the profile Cartesia is built for: developers building real-time voice agents where sub-100ms TTS latency matters (voice interruption handling, conversational feel).
- You need a general-purpose voice agents & speech/audio option rather than a vertical-specific one.
At a glance
| AssemblyAI | Cartesia | |
|---|---|---|
| Free plan | Yes | Yes |
| Entry price | Free | $5/mo |
| Enterprise available | Yes | Yes |
| Pricing model | Per Usage | Hybrid |
| Last verified | September 20, 2026 | September 20, 2026 |
| Full pricing | View full pricing | View full pricing |
Pricing last verified September 20, 2026. Tracked daily.