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Model infoModelsSnapshot: 15 Oct 2026

AI21 Labs / Jurassic-2

Jurassic-2 Large (Base)

Original Large base model from the March 2023 Jurassic-2 launch. The provider deprecated its SageMaker package and recommends Jurassic-2 Light.

Language models (LLMs)
deprecatedClosed weightsText generation
Official documentation (opens in a new tab)Reviewed 14 Oct 2026
7 of 19 specification fields collected
Context windowNot collectedAwaiting source review
Maximum outputNot collectedAwaiting source review
Input billingNot collectedAmazon SageMaker (original model package)
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 exact-version evidence collected; specifications of another model are not inherited.

Maximum input tokens
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Maximum output
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Input modalities
TextSource for Input modalities (opens in a new tab)
Output modalities
TextSource for Output modalities (opens in a new tab)
Reasoning
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Tool calling
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Structured output
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Streaming
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Batch processing
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Fine-tuning
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Context caching
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Knowledge cutoff
Mid-2022Source for Knowledge cutoff (opens in a new tab)

Original release training-data statement; no precise cutoff day is established.

Release date
2023-03-09Source for Release date (opens in a new tab)

Original base-family launch; not the launch of the later renamed instruction-following offering.

Parameters
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Architecture
Not collected

No exact-version evidence collected; specifications of another model are not inherited.

Languages
English, Spanish, French, German, Portuguese, Italian, DutchSource for Languages (opens in a new tab)
Release identity
Original base model, distinct from the later instruction-following Light offeringSource for Release identity (opens in a new tab)

Do not count the newer name as proof that the original weights remained unchanged.

Generation controls
The example accepts a prompt, maxTokens and temperature.Source for Generation controls (opens in a new tab)

Example values of 4, 30 or 100 generated tokens are not maximum output limits; no range/default is inferred.

Access & pricing

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

Amazon SageMaker (original model package)

Provider source (opens in a new tab)
API model ID
arn:aws:sagemaker:us-east-1:865070037744:model-package/j2-large-v1-0-43-03eb8175aa02346c9bd81decfd2b1e56
Access
Deprecated original model package. The recorded ARN is the documented us-east-1 package identity, not an inference endpoint name. New deployment eligibility is unverified.
Regions
Historical package map: us-east-1, us-east-2, us-west-1, us-west-2, ca-central-1, eu-central-1, eu-west-1, eu-west-2, eu-west-3, eu-north-1, ap-southeast-1, ap-southeast-2, ap-northeast-2, ap-northeast-1, ap-south-1, sa-east-1
Inference instance types
ml.g5.48xlargeSource for Inference instance types (opens in a new tab)

Example deployment instance, not a complete supported-instance list.

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

Data & enterprise terms

Retention, training use, regional processing and enterprise terms have not been summarized for this endpoint.

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.

Amazon SageMaker (original model package)

arn:aws:sagemaker:us-east-1:865070037744:model-package/j2-large-v1-0-43-03eb8175aa02346c9bd81decfd2b1e56
Not verified

No version-specific cache contract verified.

How it works
Not collected

No version-specific cache contract verified.

Minimum reusable input
Not collected

No version-specific cache contract verified.

Lifetime & refresh
Not collected

No version-specific cache contract verified.

How to enable it
Not collected

No version-specific cache contract verified.

Usage fields
Not collected

No version-specific cache contract verified.

Billing rules
Not collected

No version-specific cache contract verified.

Limits & data boundaries
Not collected

No version-specific cache contract verified.

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

Closed-weight distribution inference: the provider supplies a hosted API and a private SageMaker model package, not downloadable weights. The reviewed official AI21 public model inventory contains no matching Jurassic or GEC checkpoint. Public SDK source code is not model weights.

Classification evidence (opens in a new tab)

Lifecycle dates

Original base model announced9 Mar 2023Source (opens in a new tab)
Family simplified to Light, Mid and Ultra with instruction-following capabilities8 Jun 2023Source (opens in a new tab)

Sources reviewed