How AI avatar tools bill: credits, minutes, or seconds (Oct 2026)

Avatar tools bill in four units. Synthesia and HeyGen sell monthly credits, Tavus sells conversation minutes with a 30-second minimum per conversation, HeyGen's LiveAvatar sells its own credits where one credit is 30 seconds (Full mode) or 1 minute (Lite mode), and Sume bills per second of finished video. To compare them, convert everything to dollars for the same task.

Prices below come from vendor pages read on 2026-10-08.

One unit table

The Synthesia credit figures are from its October 1, 2026 plan article, where creating a video costs about 100 credits a minute, dubbing with lip-sync 80 credits a minute, and a survey response 350 credits.

What each unit hides

Credits hide the exchange rate: you must divide plan price by credits yourself, as in the HeyGen credit dollars post. Conversation minutes hide the floor. Per-second billing hides nothing about price but exposes the length: a script that runs longer costs more, linearly.

On Sume, the estimate is the script word count divided by 2.8 words per second, which must land in the 4-to-60-second window, so you can price a script before sending it.

A worked example

A 20-second spoken line at 56 words is about 20 seconds. On Sume Standard that is $3.68. On a Tavus conversation it is a 30-second charge, $0.185 at Starter overage. These are different products (a recorded clip versus a live exchange), so the figures only show how the unit changes the arithmetic.