GPT-5.6 Sol vs GPT-6 Astra
At a Glance
| Compare |  GPT-5.6 SolOpenAI | GPT-6 AstraOpenAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v4.4 | UnrankedNot in the 57-model eligible cohort | #6 of 5784.6 score · 3/3 sources · complete |
| CostLower is better · Published-token output estimate | UnrankedNot in the 27-model eligible cohort | #26 of 27$0.520 per LiveBench case |
| EfficiencyHigher is better · MM Efficiency v1.9 | UnrankedNot in the 27-model eligible cohort | #18 of 2746.1 score · 3/3 sources · complete |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $4.00Openai ↗ · Sep 3, 2026 | $10.00Openai ↗ · Sep 4, 2026 |
| Output priceFrom · USD / 1M tokens | $20.00Openai ↗ · Sep 3, 2026 | $50.00Openai ↗ · Sep 4, 2026 |
| Context windowMaximum documented tokens | 1,050K | 1,050K |
| Model facts checked | Aug 28, 2026View model evidence → | Sep 4, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
| Benchmark | GPT-5.6 Sol | GPT-6 Astra |
|---|---|---|
| ARC-AGI-1verified-v1-613c385b0c93 · 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-be40992860f9 · verified_score · leader | 92.5097% of row best · percent · GPT-5.6 Sol (Max) | 95.00100% of row best · percent · GPT-6 Astra (Max) |
| LMArena Document Arenadocument-2026-09-13-a64ca3b12b6e · arena_rating · statistical tie | 1,482.71100% of row best · rating · gpt-5.6-sol-xhigh; 95% CI [1473.91086026, 1491.51379085]; votes 4818; rank 10 | 1,467.5299% of row best · rating · gpt-6-astra-max; 95% CI [1453.25995337, 1481.78626802]; votes 1621; rank 16 |
| LMArena Search Arenasearch-2026-10-13-a64ca3b12b6e · arena_rating · leader | 1,261.13100% of row best · rating · gpt-5.6-sol-xhigh; 95% CI [1254.84060485, 1267.42091382]; votes 60437; rank 1 | 1,233.6298% of row best · rating · gpt-6-astra-max; 95% CI [1225.77363708, 1241.45798456]; votes 18483; rank 7 |
| LMArena Text Arenatext-2026-10-15-a64ca3b12b6e · arena_rating · leader | 1,457.06100% of row best · rating · gpt-5.6-sol-xhigh; 95% CI [1452.73485432, 1461.39117296]; votes 40442; rank 43 | 1,442.6999% of row best · rating · gpt-6-astra-max; 95% CI [1436.40189535, 1448.98654490]; votes 12163; rank 69 |
| LMArena Vision Arenavision-2026-10-09-a64ca3b12b6e · arena_rating · statistical tie | 1,281.39100% of row best · rating · gpt-5.6-sol-xhigh; 95% CI [1273.98131322, 1288.80759068]; votes 10907; rank 35 | 1,281.35100% of row best · rating · gpt-6-astra-max; 95% CI [1270.63592513, 1292.07239183]; votes 3590; rank 36 |
| LiveBench2026-06-25-90f8d44da965 · overall · leader | 85.2699% of row best · percent · gpt-5.6-sol-max · 11,729 output tokens / case | 86.47100% of row best · percent · gpt-6-astra-max · 10,407 output tokens / case |
| ToneBench2026-10-17-10-task-e9c76358afb2 · overall_score · unverified | 82.35100% of row best · points · GPT-5.6 Sol (ultra) · 15,714 output tokens / case | 82.32100% of row best · points · GPT-6 Astra (max) · 20,449 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above · 2 ties | 2 benchmark wins | 3 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.
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), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, computer-use, generation, reasoning, research, tools |
GPT-5.6 Sol Capabilities
GPT-6 Astra Capabilities
Related Comparisons
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| vs | GPT-5.6 SolOpenAI | cross-developer peersimage, text | |
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GPT-5.6 SolOpenAI | vs | GPT-6 SolOpenAI | family variantsimage, text |
GPT-5.6 SolOpenAI | vs | gpt-oss-120bOpenAI | family variantstext |
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 $4.00 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 $20.00 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?+
Both models have the same sourced context window: 1,050,000 tokens each.
Which performs better in benchmarks, GPT-5.6 Sol or GPT-6 Astra?+
GPT-6 Astra leads the current overall benchmark count. The result uses 7 protocol-matched benchmarks from 3 publishers; it is not a universal quality score.
Can GPT-5.6 Sol or GPT-6 Astra be self-hosted?+
Both models have the same sourced 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?+
Both models have the same sourced maximum output: 128,000 tokens each.
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 2, a tie.
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.