Compare AI Models Side by Side

Pick 2 to 4 models to compare benchmark scores, pricing, and specs in 2026.

GPT-6 Astra
GPT-5.6 Sol
OpenAI
GPT-6 Astra

OpenAI · GPT

OpenAI
GPT-5.6 Sol

OpenAI · GPT

Specifications

Spec
GPT-6 Astra
GPT-5.6 Sol
ProviderOpenAIOpenAI
FamilyGPTGPT
Release date2026-09-032026-07-09
Open sourceNoNo
Context window1.1M tokens1.1M tokens
Max output128K tokens128K tokens
Input price / MTok$10.00*$4.00*
Output price / MTok$50.00*$20.00*
Best foragents, coding, researchcoding, agents, reasoning

* GPT-6 Astra: Cached input $1/MTok, cache writes $12.50/MTok. Prompts over 272K input tokens are billed at 2x the input/cache rates and 1.5x the output rate for the entire request, not just the excess. | GPT-5.6 Sol: OpenAI cut pricing from launch $5/$30 to $4/$20 per MTok on Aug 21 2026, a promotion running at least through Nov 21 2026. Prompts over 272K input tokens are billed at 2x the input/cache rates and 1.5x the output rate for the entire request, not just the excess; cache writes are 1.25x the uncached input rate.

Benchmark scores (% of max)

Scores normalized to percentage of each benchmark's maximum reported value. Only officially reported scores are included.

Cost per million tokens (USD)

Context window (thousands of tokens)

Notes

GPT-6 Astra: Ships with web search, code interpreter, a hosted shell, apply-patch, computer use, and MCP support built in. Staged rollout starting with a limited partner preview Sep 3 2026, then ChatGPT Plus/Pro/Business/Enterprise plus the API and AWS over the following days. First OpenAI model to hit the 'Critical' cybersecurity threshold under the company's own Preparedness Framework; its most advanced cyber capabilities are gated behind the enterprise-only 'Daybreak' program rather than shipped broadly. Fortune reported OpenAI quietly revised some evaluation metrics upward after a delayed publication of the launch announcement, a credibility flag independent of the ARC-AGI-3 discrepancy above. Strongest, most independently-corroborated advantage across hands-on reviews is cost/token efficiency on agentic coding and robotics tasks rather than raw intelligence; the cross-vendor Artificial Analysis index and Humanity's Last Exam both still favor Claude Fable 5.1 and Opus 5. API identifier gpt-6-astra, knowledge cutoff Apr 30 2026.
GPT-5.6 Sol: Flagship of OpenAI's GPT-5.6 family (Sol/Terra/Luna tiers), announced as a limited preview Jun 26 2026 with general availability Jul 9 2026. Strong on long-horizon, command-line, and multi-step coding tasks. On the independent ARC-AGI-3 public set, OpenAI reported the official-harness score understates it: enabling retained reasoning and compaction lifted the result from 13.3% to 38.3%, beating Claude Opus 5's 30.2% on the same set — a real, reproducible optimization rather than a benchmark discrepancy, but flagged here since the two settings are not on by default. API identifier gpt-5.6-sol, knowledge cutoff Feb 16 2026. Superseded as OpenAI's flagship by GPT-6 Astra (Sep 3 2026).
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GPT-6 Astra vs GPT-5.6 Sol | AI Model Comparison