GPT-6 Astra

Sep 2026
GPT-6 Astra
Compare in
on
$2.31per task?
$10 / $50per 1M in / outcache $1
61 tok/sfirst token in 2 min?
1.05Mcontext

Rankingat xhigh effort?

Full ranking →
1Muse Wonder Full32.92GPT-5.6 Sol32.33Opus 5.531.73GPT-6.1 Sol31.75GPT-6 Astra31.45Sonnet 5.531.4

Strong at

S
Coding#2 of 132Reasoning#7 of 334Science#1 of 312Knowledge#3 of 318Vision#2 of 124
A
Agents & work tasks#25 of 175Long context#41 of 273

Benchmarks

in Chat & Knowledge
AA Intelligence Index 4.3.252.4#7
AA Omniscience Index43.4#3
AA Omniscience · Accuracy61.9#5
AA Omniscience · Hallucination Rate48.3#80
Humanity's Last Exam54.6#7
GPQA Diamond96.3#1
AA-LCR (long context) 1.180#41
CritPt (physics)31.4#5
GDP.pdf · AA all-pass32.2#2
ARC-AGI-1 · public evaluation99#2
ARC-AGI-1 · semi-private98.5#1
ARC-AGI-2 · public evaluation97.9#2
ARC-AGI-2 · semi-private93.3#2
ARC-AGI-3 · semi-private59.3#1
FrontierMath Tier 4 (v2)97.6#2
AA Cyber Index successeslab33
HealthBench Professional length-adjustedlab70.3
HealthBench length-adjustedlab58.3
HealthBench Hard length-adjustedlab36.6
HealthBench Consensus length-adjustedlab95.5

Watch out 3

Monitoring can return HTTP 403›

Misalignment monitoring can return HTTP 403 before streaming or errors after output; match misalignment_policy_violation and handle stream errors. Source ↗

No none reasoning effort›

The none reasoning effort is unsupported on GPT-6 Astra and GPT-6.1 Sol; use low instead. Source ↗

Remove unsupported sampling parameters›

When reasoning effort is not none, remove temperature, top_p and top_logprobs, plus Chat Completions logprobs or Responses output logprobs inclusion. Source ↗

FAQ

How much does GPT-6 Astra cost?›

$10 per 1M input tokens and $50 per 1M output tokens; cached input $1 per 1M. A typical benchmark task costs about $2.31 at xhigh effort.

Is GPT-6 Astra free to use?›

There is no free API; the cheapest paid price is $10 per 1M input tokens.

How good is GPT-6 Astra, and what is it best at?›

#7 of 334 in Chat & Knowledge, #2 of 132 in Coding, #7 of 133 in Agents & Tool Use, #26 of 195 in Writing & Language, #2 of 124 in Vision & Documents. Strongest at: Coding, Agents & work tasks, Reasoning, Science, Long context, Knowledge, Vision.

Is GPT-6 Astra better than Claude Opus 5.5?›

On CritPt (physics), GPT-6 Astra scores 31.7 vs 31.7 — about the same. It is 61% cheaper per task.

How can I use GPT-6 Astra?›

Through the API of Amazon Bedrock, Azure, OpenAI.

What is the context window of GPT-6 Astra?›

1.05M tokens, with up to 128K output tokens.

When was GPT-6 Astra released? Is there a newer version?›

Released 2026-09-04. It is the current version in its line.

Is GPT-6 Astra open source?›

No, GPT-6 Astra is a closed model available through an API. The closest open-weights option here is MiMo v2.6 Pro.

Can GPT-6 Astra read images?›

It accepts text and images, PDF files as input.

What is GPT-6 Astra?›

GPT-6 Astra is a closed language model from OpenAI, released Sep 2026.

What are the best alternatives to GPT-6 Astra?›

GPT-5.6 Sol (cheaper), MiMo v2.6 Pro (open weights).