GPT-5.6 Sol changelog

GPT-5.6 Sol price cut to $4 input and $20 output

GPT-5.6 Sol now costs $4 per million input tokens and $20 per million output tokens, 20% lower for input and 33% lower for output.

Who is affected:

Apps using GPT-5.6 Sol.

What to do:

No action needed. Note this is promotional pricing (see the November 21 event).

GPT-5.6 Sol promotional price runs at least through November 21

GPT-5.6 Sol's promotional pricing ($4 input, $20 output per million tokens) runs at least through November 21, 2026. OpenAI has not said what the price will be after that date.

Takes effect Nov 21, 2026 · in 20 days

Who is affected:

Apps budgeting on GPT-5.6 Sol at the promotional price.

Action needed:

Budget for a possible price increase after November 21, 2026, or evaluate GPT-6.1 Sol.

Ultrafast service tier announced for GPT-5.6 Sol

OpenAI announced Ultrafast, an API service tier running GPT-5.6 Sol up to 14 times faster than Standard, in limited preview.

ChatGPT replaces GPT-5.5 Instant with GPT-5.6 Sol and Luna

Free and Go users got a new default model for everyday chats, and Plus and Pro users got an updated GPT-5.6 Sol with an effort slider. These models replaced GPT-5.5 Instant.

Who is affected:

Everyone using ChatGPT.

What to do:

No action needed. Expect different answers than GPT-5.5 Instant.

Fast mode replaces Priority Processing

Fast mode replaced the Priority Processing tier. For GPT-5.6 Sol it runs up to 2.5 times faster than standard processing at twice the price, and requests tagged priority automatically use Fast mode.

Who is affected:

API customers who used Priority Processing.

What to do:

Check your bills for Fast mode pricing on requests tagged priority.

GPT-5.6 Sol, Terra and Luna available in GitHub Copilot

GPT-5.6 Sol is available on Copilot Pro+, Max, Business and Enterprise. Terra and Luna are also available on Pro. All are billed at provider list price, and Business and Enterprise admins must turn on the policy, which is off by default.

Who is affected:

GitHub Copilot users choosing OpenAI models.

What to do:

Copilot Business and Enterprise admins: enable the GPT-5.6 policy if you want these models.

GPT-5.6 family released: Sol, Terra and Luna

OpenAI released three GPT-5.6 models on the Responses, Chat Completions and Batch APIs. The gpt-5.6 alias routes to gpt-5.6-sol, and the release adds max reasoning effort, Pro mode and multi-agent orchestration in beta.

Who is affected:

Developers on GPT-5.5, GPT-5.4 and older models.

What to do:

Evaluate gpt-5.6-terra or gpt-5.6-luna for cost-sensitive workloads.