Legacy model information

This page gives you information about legacy generative AI models on Vertex AI. The models in a legacy model family are no longer updated with new stable versions. After all stable versions of a legacy model reach their discontinuation dates, the model family is no longer supported.

PaLM API models

The following table summarizes PaLM API legacy models:

Model name Description Model properties Tuning support
PaLM 2 for Text
(text-bison)
Fine-tuned to follow natural language instructions and is suitable for a variety of language tasks, such as classification, summarization, and extraction. Maximum input tokens: 8192
Maximum output tokens: 1024
Training data: Up to Feb 2023
Supervised: Yes
RLHF: Yes (Preview)
Distillation: No
PaLM 2 for Text (text-unicorn) The most advanced text model in the PaLM family of models for use with complex natural language tasks. Maximum input tokens: 8192
Maximum output tokens: 1024
Training data: Up to Feb 2023
Supervised: No
RLHF: No
Distillation: Yes (Preview)
PaLM 2 for Text 32k
(text-bison-32k)
Fine-tuned to follow natural language instructions and is suitable for a variety of language tasks. Max tokens (input + output): 32,768
Max output tokens: 8,192
Training data: Up to Aug 2023
Supervised: Yes
RLHF: No
Distillation: No
PaLM 2 for Chat
(chat-bison)
Fine-tuned for multi-turn conversation use cases. Maximum input tokens: 8192
Maximum output tokens: 2048
Training data: Up to Feb 2023
Maximum turns : 2500
Supervised: Yes
RLHF: No
Distillation: No
PaLM 2 for Chat 32k
(chat-bison-32k)
Fine-tuned for multi-turn conversation use cases. Max tokens (input + output): 32,768
Max output tokens: 8,192
Training data: Up to Aug 2023
Max turns : 2500
Supervised: Yes
RLHF: No
Distillation: No

Codey APIs models

The following table summarizes Codey APIs legacy models. Note that code-gecko code completion model is not a legacy model.

Model name Description Model properties Tuning support
Codey for Code Generation
(code-bison)
A model fine-tuned to generate code based on a natural language description of the desired code. For example, it can generate a unit test for a function. Maximum input tokens: 6144
Maximum output tokens: 1024
Supervised: Yes
RLHF: No
Distillation: No
Codey for Code Generation 32k
(code-bison-32k)
A model fine-tuned to generate code based on a natural language description of the desired code. For example, it can generate a unit test for a function. Max tokens (input + output): 32,768
Max output tokens: 8,192
Supervised: Yes
RLHF: No
Distillation: No
Codey for Code Chat
(codechat-bison)
A model fine-tuned for chatbot conversations that help with code-related questions. Maximum input tokens: 6144
Maximum output tokens: 1024
Supervised: Yes
RLHF: No
Distillation: No
Codey for Code Chat 32k
(codechat-bison-32k)
A model fine-tuned for chatbot conversations that help with code-related questions. Max tokens (input + output): 32,768
Max output tokens: 8,192
Supervised: Yes
RLHF: No
Distillation: No

Language support

Vertex AI PaLM API and Codey APIs legacy models support the following languages:

  • Arabic (ar)
  • Bengali (bn)
  • Bulgarian (bg)
  • Chinese simplified and traditional (zh)
  • Croatian (hr)
  • Czech (cs)
  • Danish (da)
  • Dutch (nl)
  • English (en)
  • Estonian (et)
  • Finnish (fi)
  • French (fr)
  • German (de)
  • Greek (el)
  • Hebrew (iw)
  • Hindi (hi)
  • Hungarian (hu)
  • Indonesian (id)
  • Italian (it)
  • Japanese (ja)
  • Korean (ko)
  • Latvian (lv)
  • Lithuanian (lt)
  • Norwegian (no)
  • Polish (pl)
  • Portuguese (pt)
  • Romanian (ro)
  • Russian (ru)
  • Serbian (sr)
  • Slovak (sk)
  • Slovenian (sl)
  • Spanish (es)
  • Swahili (sw)
  • Swedish (sv)
  • Thai (th)
  • Turkish (tr)
  • Ukrainian (uk)
  • Vietnamese (vi)

Legacy model discontinuation date

The following table shows the discontinuation date of legacy models:

chat-bison model Release date Discontinuation date
chat-bison@002 December 6, 2023 April 9, 2025
chat-bison-32k model Release date Discontinuation date
chat-bison-32k@002 December 4, 2023 April 9, 2025
code-bison model Release date Discontinuation date
code-bison@002 December 6, 2023 April 9, 2025
code-bison-32k model Release date Discontinuation date
code-bison-32k@002 December 4, 2023 April 9, 2025
codechat-bison model Release date Discontinuation date
codechat-bison@002 December 6, 2023 April 9, 2025
codechat-bison-32k model Release date Discontinuation date
codechat-bison-32k@002 December 4, 2023 April 9, 2025
text-bison model Release date Discontinuation date
text-bison@002 December 6, 2023 April 9, 2025
text-bison-32k model Release date Discontinuation date
text-bison-32k@002 December 4, 2023 April 9, 2025
text-unicorn model Release date Discontinuation date
text-unicorn@001 November 30, 2023 April 9, 2025

Legacy models that support Provisioned Throughput

This table shows legacy models that support Provisioned Throughput, which is measured in characters per second, minimum purchase increments, and burndown rates.

Model Throughput per GSU Minimum GSU purchase increment Burndown rates
text-bison, chat-bison, code-bison, codechat-bison 4,000 1 1 input char = 1 char
1 output char = 2 chars
text-unicorn 400 1 1 input char = 1 char
1 output char = 3 chars