GPT-5.6 Sol vs GPT-6 Astra
Why this pair: OpenAI's current flagship versus its immediate flagship predecessor
Model Markets Rankings
Intelligence, Cost, and Efficiency
| Ranking | GPT-5.6 Sol | GPT-6 Astra |
|---|---|---|
| CostLower is better · Published-token output estimate | #20 of 36$0.117 per LiveBench case | UnrankedNot in the 36-model eligible cohort |
Ranks come from the current complete eligible cohorts. Green highlights appear only when both models are ranked in the same metric. Missing required inputs remain unranked, and the three dimensions are not collapsed into an overall winner.
Benchmark Performance
Available Benchmarks
| Benchmark | GPT-5.6 Sol | GPT-6 Astra |
|---|---|---|
| ARC-AGI-1verified-v1-2aa739d957fc · verified_score · leader | 97.5099% of row best · percent · GPT-5.6 Sol (XHigh) | 98.50100% of row best · percent · GPT-6 Astra (XHigh) |
| ARC-AGI-2verified-v2-b5cb5ec6e8c7 · verified_score · leader | 92.5097% of row best · percent · GPT-5.6 Sol (Max) | 95.00100% of row best · percent · GPT-6 Astra (Max) |
| Overall ResultCounted from the protocol-matched rows above | 0 benchmark wins | 2 benchmark winsOverall lead |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Technical Differences
Side-by-Side Facts
| Field | GPT-5.6 Sol | GPT-6 Astra |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Family | Gpt 5 6 | Gpt 6 |
| Model | GPT-5.6 Sol | GPT-6 Astra |
| Version | GPT-5.6 Sol | GPT-6 Astra |
| Lifecycle | active | active |
| Released | Unknown | 2026-09-03 |
| Knowledge cutoff | 2026-02-16 | 2026-04-30 |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,050K | 1,050K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Openai (Standard), Openrouter (Standard) | Openai (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, computer-use, generation, reasoning, research, tools |
14 comparable fields · 6 material differences · Editorially curated pair passes the primary-source comparison gate
GPT-5.6 Sol Capabilities
GPT-6 Astra Capabilities
Internal Comparison Graph
Related Comparisons
| A | Pair | B | Context |
|---|---|---|---|
Claude Fable 5.1Anthropic | vs | GPT-5.6 SolOpenAI | cross-developer peersimage, text |
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GPT-5.6 SolOpenAI | vs | Grok 4.6xAI | cross-developer peersimage, text |
GPT-5.6 SolOpenAI | vs |  Qwen3.8-MaxQwen | cross-developer peersimage, text |
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 MiniMax-M3MiniMax | vs | GPT-5.6 SolOpenAI | cross-developer peersimage, text |
GPT-5.6 SolOpenAI | vs |  GLM-5.3Z.ai | cross-developer peerstext |
GPT-5.6 SolOpenAI | vs |  Hy4 previewTencent | cross-developer peerstext |
Seed 2.1 ProByteDance Seed | vs | GPT-5.6 SolOpenAI | cross-developer peersimage, text |
 Mistral Large 3Mistral AI | vs | GPT-5.6 SolOpenAI | cross-developer peersimage, text |
| vs | GPT-5.6 SolOpenAI | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
GPT-5.6 Sol vs GPT-6 Astra FAQs
Is GPT-5.6 Sol or GPT-6 Astra better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both GPT-5.6 Sol and GPT-6 Astra, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, GPT-5.6 Sol or GPT-6 Astra?+
GPT-5.6 Sol is $2.00 and GPT-6 Astra is $10.00 per million tokens, so GPT-5.6 Sol is cheaper on this metric. GPT-5.6 Sol is $10.00 and GPT-6 Astra is $50.00 per million tokens, so GPT-5.6 Sol is cheaper on this metric.
Which has a larger context window, GPT-5.6 Sol or GPT-6 Astra?+
Neither model has a larger sourced context window in this comparison. GPT-5.6 Sol is 1,050K and GPT-6 Astra is 1,050K.
Which performs better in benchmarks, GPT-5.6 Sol or GPT-6 Astra?+
There is no overall benchmark winner: An overall winner requires at least two decisive benchmarks from at least two original publishers.
Can GPT-5.6 Sol or GPT-6 Astra be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. GPT-5.6 Sol is not marked open weight; GPT-6 Astra is not marked open weight.
Can GPT-5.6 Sol and GPT-6 Astra understand images?+
GPT-5.6 Sol is documented with image input; GPT-6 Astra is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, GPT-5.6 Sol or GPT-6 Astra?+
Neither has a larger sourced maximum output. GPT-5.6 Sol is 128K and GPT-6 Astra is 128K.
Do GPT-5.6 Sol and GPT-6 Astra support reasoning and tool use?+
GPT-5.6 Sol: reasoning, tool calling, and image input. GPT-6 Astra: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, GPT-5.6 Sol or GPT-6 Astra?+
GPT-5.6 Sol has 2 sourced provider routes; GPT-6 Astra has 1, so GPT-5.6 Sol has broader tracked availability.
Which offers better value, GPT-5.6 Sol or GPT-6 Astra?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.