Compare to

Discover how Open AI's GPT-6 Astra and Open AI's GPT-5.6 Sol stack up against each other in this comprehensive comparison of two leading AI language models. Released in September 2026 and July 2026 respectively, these models represent significant advancements in artificial intelligence, with GPT-6 Astra offering a 1,050,000-token context window and GPT-5.6 Sol offering a 1,050,000-token context window.

Explore their capabilities, pricing, and performance metrics, with GPT-6 Astra achieving 1,480 on LMArena Elo and GPT-5.6 Sol scoring 1,483, making this comparison essential for developers and organizations seeking the right AI solution for their specific needs.

Models Overview

	GPT-6 Astra	GPT-5.6 Sol
Provider The company that provides the model.	Open AI	Open AI
Context Length Maximum number of tokens the model can process	1.05M	1.05M
Maximum Output Maximum number of tokens the model can generate in one response	128K	128K
Release Date When the model was first released.	03-09-2026	09-07-2026
Knowledge Cutoff When the model's training data ends.	2026-04-30	2026-02-16
Open Source Whether the model weights are openly available.	FALSE	FALSE

Pricing Comparison

Compare the pricing of Open AI's GPT-6 Astra and Open AI's GPT-5.6 Sol to determine the most cost-effective solution for your AI needs. Prices are the standard API tier per million tokens, as published by each provider as of September 2026.

	GPT-6 Astra	GPT-5.6 Sol
Input Cost Cost per million input tokens	$10 / 1M tokens	$4 / 1M tokens
Output Cost Cost per million tokens generated	$50 / 1M tokens	$20 / 1M tokens

Comparing Benchmarks and Performance

Compare the performances of Open AI's GPT-6 Astra and Open AI's GPT-5.6 Sol on industry benchmarks. Scores are the ones the providers and public leaderboards report; a benchmark neither reports is left out.

	GPT-6 Astra	GPT-5.6 Sol
LMArena Elo Crowd-sourced blind preference rating on the LMArena text leaderboard.	1,480	1,483
Terminal-Bench 2.1 Agentic tasks completed in a real terminal.	Benchmark not available	88.8%*

* Score published by another provider's comparison table, not by the model's own provider.

Sources — GPT-6 Astra: developers.openai.com, arena.ai; GPT-5.6 Sol: developers.openai.com, community.openai.com, arena.ai, deepmind.google.