Claude Opus 4.8 vs GPT-5.6 Terra
At a Glance
| Compare | Claude Opus 4.8Anthropic |  GPT-5.6 TerraOpenAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #18 of 4670.1 score · 3/3 sources · complete | #13 of 4674.9 score · 3/3 sources · complete |
| CostLower is better · Published-token output estimate | #42 of 44$0.604 per LiveBench case | #35 of 44$0.266 per LiveBench case |
| EfficiencyHigher is better · MM Efficiency v1.5 | #35 of 3840.5 score · 3/3 sources · complete | #23 of 3851.5 score · 3/3 sources · complete |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $5.00Anthropic ↗ · Sep 3, 2026 | $2.00Openai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $25.00Anthropic ↗ · Sep 3, 2026 | $12.00Openai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,000K | 1,050K |
| Model facts checked | Aug 29, 2026View model evidence → | Aug 28, 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 | Claude Opus 4.8 | GPT-5.6 Terra |
|---|---|---|
| ARC-AGI-1verified-v1-ba05d69f6453 · verified_score · leader | 92.5096% of row best · percent · Claude Opus 4.8 (Max) | 96.50100% of row best · percent · GPT-5.6 Terra (Max) |
| ARC-AGI-2verified-v2-6c676fa3e9af · verified_score · leader | 72.0886% of row best · percent · Claude Opus 4.8 (High) | 83.90100% of row best · percent · GPT-5.6 Terra (Max) |
| LMArena Agent Arenaagent-2026-09-15-d25aabda0010 · outcome_score · leader | 8.19100% of row best · score · Claude Opus 4.8 (High); 95% CI [6.91963673, 9.45737628]; sessions 39731; observations 2097389; rank 6 | 1.4494% of row best · score · GPT 5.6 Terra (xHigh); 95% CI [0.32735411, 2.55262103]; sessions 20301; observations 1231027; rank 23 |
| LMArena Document Arenadocument-2026-09-13-d25aabda0010 · arena_rating · statistical tie | 1,464.0799% of row best · rating · claude-opus-4-8; 95% CI [1457.10320334, 1471.03216030]; votes 12128; rank 19 | 1,471.58100% of row best · rating · gpt-5.6-terra-xhigh; 95% CI [1463.31179298, 1479.85049651]; votes 5787; rank 13 |
| LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · statistical tie | 1,452.66100% of row best · rating · claude-opus-4-8; 95% CI [1448.52490690, 1456.79817098]; votes 53446; rank 40 | 1,446.22100% of row best · rating · gpt-5.6-terra-xhigh; 95% CI [1441.41414497, 1451.02563541]; votes 28119; rank 52 |
| LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · leader | 1,288.23100% of row best · rating · claude-opus-4-8; 95% CI [1281.27991800, 1295.18871241]; votes 15801; rank 25 | 1,269.9099% of row best · rating · gpt-5.6-terra-xhigh; 95% CI [1261.54272100, 1278.25950723]; votes 7726; rank 36 |
| LiveBench2026-06-25 · overall · leader | 81.1899% of row best · percent · claude-opus-4-8-max-effort · 24,171 output tokens / case | 82.31100% of row best · percent · gpt-5.6-terra-max · 22,145 output tokens / case |
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 87.91100% of row best · points · Claude Opus 4.8 (max effort) · 24,846 output tokens / case | 86.3998% of row best · points · GPT-5.6 Terra (ultra) · 11,336 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 | Claude Opus 4.8 | GPT-5.6 Terra |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Family | Claude 4 8 | Gpt 5 6 |
| Model | Claude Opus 4.8 | GPT-5.6 Terra |
| Version | Claude Opus 4.8 | GPT-5.6 Terra |
| Lifecycle | active | active |
| Released | 2026-05-28 | Unknown |
| Knowledge cutoff | 2026-01-01 | 2026-02-16 |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,000K | 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 | Anthropic (Standard), Deepinfra (Standard) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, tools |
Claude Opus 4.8 Capabilities
GPT-5.6 Terra Capabilities
Related Comparisons
All image comparisons →| A | Pair | B | Context |
|---|---|---|---|
Claude Opus 4.8Anthropic | vs | GPT-6 AstraOpenAI | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs | Claude Opus 4.8Anthropic | family variantsimage, text |
Claude Opus 4.8Anthropic | vs |  Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Claude Opus 4.8Anthropic | vs |  DeepSeek-V4.1-FlashDeepSeek | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  Qwen3.8-MaxQwen | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  Kimi-K3Moonshot AI | cross-developer peersimage, text |
 MiniMax-M3MiniMax | vs | Claude Opus 4.8Anthropic | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Claude Opus 4.8Anthropic | vs |  Hy4 previewTencent | cross-developer peerstext |
Claude Opus 4.8Anthropic | vs | Seed 2.1 ProByteDance Seed | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  Mistral Large 3Mistral AI | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Opus 4.8 vs GPT-5.6 Terra FAQs
Is Claude Opus 4.8 or GPT-5.6 Terra better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Opus 4.8 and GPT-5.6 Terra, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Opus 4.8 or GPT-5.6 Terra?+
Claude Opus 4.8 is $5.00 and GPT-5.6 Terra is $2.00 per million tokens, so GPT-5.6 Terra is cheaper on this metric. Claude Opus 4.8 is $25.00 and GPT-5.6 Terra is $12.00 per million tokens, so GPT-5.6 Terra is cheaper on this metric.
Which has a larger context window, Claude Opus 4.8 or GPT-5.6 Terra?+
GPT-5.6 Terra has the larger sourced context window. Claude Opus 4.8 supports 1,000K and GPT-5.6 Terra supports 1,050K.
Which performs better in benchmarks, Claude Opus 4.8 or GPT-5.6 Terra?+
GPT-5.6 Terra leads the current overall benchmark count. The result uses 7 protocol-matched benchmarks from 3 publishers; it is not a universal quality score.
Can Claude Opus 4.8 or GPT-5.6 Terra be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Opus 4.8 is not marked open weight; GPT-5.6 Terra is not marked open weight.
Can Claude Opus 4.8 and GPT-5.6 Terra understand images?+
Claude Opus 4.8 is documented with image input; GPT-5.6 Terra is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Opus 4.8 or GPT-5.6 Terra?+
Neither has a larger sourced maximum output. Claude Opus 4.8 is 128K and GPT-5.6 Terra is 128K.
Do Claude Opus 4.8 and GPT-5.6 Terra support reasoning and tool use?+
Claude Opus 4.8: reasoning, tool calling, and image input. GPT-5.6 Terra: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Opus 4.8 or GPT-5.6 Terra?+
Claude Opus 4.8 has 2 sourced provider routes; GPT-5.6 Terra has 2, a tie.
Which offers better value, Claude Opus 4.8 or GPT-5.6 Terra?+
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.