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Model infoModelsSnapshot: 15 Oct 2026

Synthesia / Synthesia avatar models

Express-Eval

Internal audio-motion alignment model that scores candidate performances for the Express-2 pipeline.

Audio processing
restrictedClosed weightsAudio processing
Official documentation (opens in a new tab)Reviewed 14 Oct 2026
3 of 16 specification fields collected
Context windowNot collectedAwaiting source review
Maximum outputNot collectedAwaiting source review
Input billingNot collectedSynthesia
Output billingNot collectedNo inferred price

Specifications

Provider-documented facts. “Not collected” means we have not verified that field yet, not that the feature is unsupported.

Context / input limit
Not collected

No model-specific public value established in the reviewed sources.

Maximum output
Not collected

No model-specific public value established in the reviewed sources.

Context caching
Not collected

No model-specific public value established in the reviewed sources.

Reasoning
Not collected

No model-specific public value established in the reviewed sources.

Tool calling
Not collected

No model-specific public value established in the reviewed sources.

Structured output
Not collected

No model-specific public value established in the reviewed sources.

Streaming
Not collected

No model-specific public value established in the reviewed sources.

Batch processing
Not collected

No model-specific public value established in the reviewed sources.

Fine-tuning
Not collected

No model-specific public value established in the reviewed sources.

Parameters
Not collected

No model-specific public value established in the reviewed sources.

Architecture
CLIP-like contrastive audio-motion encoder with cosine-similarity scoringSource for Architecture (opens in a new tab)

Trained on proprietary paired audio and motion. This does not establish a public general-purpose embedding endpoint.

Knowledge cutoff
Not collected

No model-specific public value established in the reviewed sources.

Languages
Not collected

No model-specific public value established in the reviewed sources.

Release date
Not collected

No model-specific public value established in the reviewed sources.

Input modalities
Audio, Human motionSource for Input modalities (opens in a new tab)
Output modalities
Alignment scoresSource for Output modalities (opens in a new tab)

Access & pricing

Prices belong to an endpoint and billing tier. A provider listing does not guarantee access for every account or region.

Synthesia

Provider source (opens in a new tab)
API model ID
Not collected

Avatar IDs, voice IDs and component labels are not public immutable model checkpoint selectors.

Access
Named internal component of the Express-2 pipeline. No independently callable public endpoint or separately metered tariff is documented.
Regions
AWS public-cloud hosting; no model-specific regional processing guarantee established.
Pricing terms
No standalone public component tariff. Do not allocate the studio subscription price across internal submodels.Source for Pricing terms (opens in a new tab)

Endpoint pricing has not been collected. Check the provider for applicable rates.

Data & enterprise terms

Hosted on AWS. Customer data deletion is described as taking up to 90 days, with residual backups subject to their lifecycle. Service-improvement terms permit usage analysis within specified customer-instruction and consent restrictions; this is not a universal no-training or zero-retention promise.

Read the service policy (opens in a new tab)

Caching

Caching can reuse earlier input processing. Availability, lifetime and billing depend on the endpoint. A cache hit still generates a new response.

01 / INITIAL INPUTProcess & retain

The system processes eligible input and retains reusable state.

02 / LATER REQUESTCheck available state

Reuse depends on matching input, session state and the cache policy.

03 / CACHE HITReuse & generate

Reusing state can reduce repeated work. Any charges follow the billing rules below.

Synthesia

Not verified

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

How it works
Not collected

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

Minimum reusable input
Not collected

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

Lifetime & refresh
Not collected

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

How to enable it
Not collected

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

Usage fields
Not collected

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

Billing rules
Not collected

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

Limits & data boundaries
Not collected

Saved avatars, reusable videos and enrollment reuse are not documented prompt caching or discounted input-token billing.

No verified cache rate for this endpoint. An empty rate is not a zero charge.

Caching reviewed 14 Oct 2026

What the measurements say

No benchmark observations have been added for this model. We do not turn a vendor description into a performance score.

Latency and throughput depend on the host, request size, reasoning settings and load. There is no measured speed or global usage figure in this record.

The record behind the model

Why it is included

Synthesia identifies this named model in its proprietary research or product materials. No public model weights or permissive weight license are established; open client code does not expose the serving model.

Classification evidence (opens in a new tab)

Sources reviewed