Synthesia API pricing: which plan, and how credits work

Synthesia's API comes with a subscription plan: API access is included from the Creator plan ($89 a month, or $64 a month billed yearly) up, and API video is paid for in the plan's credits. Its pricing FAQ says there is no paying per video. Synthesia's help center lists 1 minute of API usage at 75 credits, and Creator includes 3,600 credits a month.

All Synthesia figures below come from Synthesia's pricing page, its credits article and its API docs, read on 2026-09-28. Sume figures come from Sume's pricing code and Generate avatar video.

Which Synthesia plan includes API access?

The Video API page says: "Access to Synthesia's API is available for Creator plans or above." On the pricing page, API access first appears on the Creator card, and the plan comparison says the API gives "Up to 360 minutes of video / year, deducted from the plan's usage limits."

How do Synthesia credits work?

Synthesia calls credits "the shared currency across all AI usage-based features - one common pool for everything you create." Different features draw from that pool at different rates:

• Video in general: each second uses 2 credits, so a one-minute video uses 120 credits.
• API usage is listed separately: 1 minute of API usage uses 75 credits. The article doesn't say how this rate and the per-second rate combine for one API video, so check the usage figures on Synthesia's Developers page after a test render.
• 1 minute of Interactive Avatar API usage uses 10 credits; the Interactive Avatars docs put that at $0.10 per minute.
• Credits reset at the start of each billing period and do not roll over. When you run out, you can top up or move to a higher plan.

What does the Synthesia API include?

Synthesia lists four APIs: Interactive Avatars (a live, streaming avatar), the Video API (finished video files, asynchronous, with polling or a webhook), an Upload API for your own assets, and a Billing API that returns your credit balance.

• Keys: create one under Developers → API keys. The Video API needs a Legacy (v2)-scoped key; an Interactive Avatars key won't work there. Keys expire after 30 days by default.
• Rate limits on Creator (Tier 3): 60 write requests per minute, 300 per hour, and 1,000 per day per endpoint. Over the limit you get 429 Too Many Requests.
• Test videos: 30 per day.

How does Sume bill an avatar API instead?

Sume prices avatar video by output second rather than by plan credits: $0.184/s standard, $0.245/s plus, $0.55/s max (no product image), plus $0.95 per avatar once for each reusable avatar, each plus a 5.5% agent fee by default. Usage draws from one prepaid wallet.

One Sume talking video covers an estimated 4-60 seconds of script. Sume vs Synthesia compares the products, and AI avatar video pricing per minute converts Sume's rates to minutes; the live rate card is on API pricing.