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AI21 LabsJurassic-2

Jurassic-2 Ultra

Jurassic-2 Ultra replaced the Jumbo size name in the June 2023 lineup. AI21 positioned it as the most capable and highest-latency tier.

Access not confirmed

The second Jurassic generation added language support

Jurassic-2's launch documented English plus Spanish, French, German, Portuguese, Italian and Dutch, with training data through mid-2022.Jurassic-2 and task-specific API launch

Controls extended beyond temperature

The Bedrock interface exposed repetition penalties that could be configured for spaces, punctuation, numbers and stop words.Jurassic-2's historical Amazon Bedrock request format

Practical guidance. Applications depending on these controls need to check the replacement API's behavior. Matching temperature alone is not enough to reproduce an older integration.

Keep the historical name separate from Jamba

AI21 directed Jurassic users toward Jamba in its Q3 2024 deprecation notice.AI21's historical Jurassic-to-Jamba migration notice

Practical guidance. Current access to Ultra is not confirmed. It is not a Jamba alias, and the original Jurassic-1 Jumbo parameter count is not a verified specification for Ultra.

Specifications & access

Jurassic-2 Ultra specifications
DetailValue and conditions
StatusAccess not confirmed
Launch date
Model identifiersJ2-Ultraj2-ultraJ2-Jumbo Instructai21.j2-ultra-v1
Historical instruction-model nameJumbo InstructJurassic-2 and task-specific API launchAI21 simplifies Jurassic-2 to Light, Mid and Ultra

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