What's the difference between Cartesia and Synthflow?

Cartesia is 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, while Synthflow is No-code AI voice agent builder with tiered subscriptions + per-minute overages. Starter $29 (50 min), Pro $99 (200 min), Growth $449 (1000 min), Agency $899 (2000 min), Enterprise custom (10K+ min). White-label option runs ~$2,000/mo. Voice engine alone ~$0.09/min; all-in $0.15–0.37/min with LLM + telephony. On price, cartesia is cheaper on the entry tier at $5/mo vs $29/mo for Synthflow. Both bill on a hybrid model, so the tiers below compare directly.

Which costs less, Cartesia or Synthflow?

Cartesia is cheaper on the entry tier at $5/mo vs $29/mo for Synthflow.

Is Cartesia or Synthflow priced per seat or per usage?

Cartesia is hybrid: a fixed subscription from $5/mo plus metered usage on top. Your real bill moves with volume, not seat count. Synthflow is hybrid: a fixed subscription from $29/mo plus metered usage on top (Starter). Your real bill moves with volume, not seat count.

Does Cartesia have a free plan?

Cartesia's free-plan availability isn't confirmed — check the pricing page for the latest.

Does Synthflow have a free plan?

Synthflow's free-plan availability isn't confirmed — check the pricing page for the latest.

How does Cartesia pricing compare to Synthflow for enterprise use?

Neither Cartesia nor Synthflow publishes a dedicated enterprise tier. Contact each vendor to discuss custom volume pricing.

When were these prices last verified?

Pricing was last checked on October 3, 2026.

Cartesia vs Synthflow — Pricing, Plans, and Verified Costs (2026)

TL;DR

Cartesia starts at $5/mo. Synthflow starts at $29/mo. Cartesia is $24/mo cheaper on the entry tier than Synthflow.

Checked September 29, 2026

See price history: Cartesia · Synthflow

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.

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.
Synthflow (Hybrid) — Synthflow is hybrid: a fixed subscription from $29/mo plus metered usage on top (Starter). 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.

Cartesia

Voice Agents & Speech/Audio

Starts at

$5/mo

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.

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Synthflow

Voice Agents & Speech/Audio

Starts at

$29/mo

No-code AI voice agent builder with tiered subscriptions + per-minute overages. Starter $29 (50 min), Pro $99 (200 min), Growth $449 (1000 min), Agency $899 (2000 min), Enterprise custom (10K+ min). White-label option runs ~$2,000/mo. Voice engine alone ~$0.09/min; all-in $0.15–0.37/min with LLM + telephony.

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All plans compared

Tier role	Plan	Cartesia monthly	Cartesia annual	Synthflow monthly	Synthflow annual
Free / starter	Free / —	Free	Free	—	—
Entry paid	Pro / Starter	$5	$5	$29	$29
Mid tier 1	Startup / Pro	$49	$49	$99	$99
Mid tier 2	— / Growth	—	—	$449	$449
Pro / power	Scale / Agency	$299	$299	$899	$899
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

Cartesia

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.

Synthflow

Synthflow is worth it if… small businesses and agencies that want no-code AI voice agents without touching a developer platform like Vapi or Retell. Starter ($29) makes prototyping cheap.

Bottom line: Similar positioning, closer to a preference call than a strategic one.

Choose Cartesia over Synthflow if…

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.

Choose Synthflow if…

You're fine with a base subscription plus metered usage on top (from $29/mo).
You match the profile Synthflow is built for: small businesses and agencies that want no-code AI voice agents without touching a developer platform like Vapi or Retell.
You need a general-purpose voice agents & speech/audio option rather than a vertical-specific one.

At a glance

	Cartesia	Synthflow
Free plan	Yes	No
Entry price	$5/mo	$29/mo
Enterprise available	Yes	Yes
Pricing model	Hybrid	Hybrid
Verification	Checked September 29, 2026	Checked October 3, 2026
Full pricing	View full pricing	View full pricing