Compare models
GPT-5.6 Sol
GPT-5.6 flagship model for complex professional work
Reasoning
Speed
Input
Output
Reasoning tokens
Pricing
Text tokens
Input / 1M tokens
$4.00
Cached input / 1M tokens
$0.40
Output / 1M tokens
$20.00
Cache writes / 1M tokens
-
Context
Window
1,050,000
Max Output Tokens
128,000
Knowledge Cutoff
Feb 16, 2026
Endpoints
v1/chat/completions
v1/responses
v1/batch
Supported Features
Streaming
Function calling
Structured outputs
Image input
Rate Limits
TPM
Free
-
Build
1,000,000
Launch
4,000,000
Grow
40,000,000
GPT-6 Astra
Our most capable model for the most demanding work.
Reasoning
Speed
Input
Output
Reasoning tokens
Pricing
Text tokens
Input / 1M tokens
$10.00
Cached input / 1M tokens
$1.00
Output / 1M tokens
$50.00
Cache writes / 1M tokens
$12.50
Context
Window
1,050,000
Max Output Tokens
128,000
Knowledge Cutoff
Apr 30, 2026
Endpoints
v1/chat/completions
v1/responses
v1/batch
Supported Features
Streaming
Function calling
Structured outputs
Image input
Rate Limits
TPM
Free
-
Build
1,000,000
Launch
4,000,000
Grow
40,000,000