Claude Opus 4.8 vs GPT-5.5
At a Glance
| Compare | Claude Opus 4.8Anthropic |  GPT-5.5OpenAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #18 of 4670.1 score · 3/3 sources · complete | #7 of 4683.9 score · 3/3 sources · complete |
| CostLower is better · Published-token output estimate | #42 of 44$0.604 per LiveBench case | #38 of 44$0.341 per LiveBench case |
| EfficiencyHigher is better · MM Efficiency v1.5 | #35 of 3840.5 score · 3/3 sources · complete | #18 of 3853.4 score · 3/3 sources · complete |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $5.00Anthropic ↗ · Sep 3, 2026 | $5.00Openai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $25.00Anthropic ↗ · Sep 3, 2026 | $30.00Openai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,000K | 1,050K |
| Model facts checked | Aug 29, 2026View model evidence → | Sep 3, 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-5.5 |
|---|---|---|
| ARC-AGI-1verified-v1-ba05d69f6453 · verified_score · leader | 92.5097% of row best · percent · Claude Opus 4.8 (Max) | 95.00100% of row best · percent · GPT-5.5 (XHigh) |
| ARC-AGI-2verified-v2-6c676fa3e9af · verified_score · leader | 72.0885% of row best · percent · Claude Opus 4.8 (High) | 85.00100% of row best · percent · GPT-5.5 (XHigh) |
| 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 | 2.6795% of row best · score · GPT 5.5; 95% CI [1.85777151, 3.48040109]; sessions 81254; observations 2107641; rank 20 |
| LMArena Document Arenadocument-2026-09-13-d25aabda0010 · arena_rating · leader | 1,464.0799% of row best · rating · claude-opus-4-8; 95% CI [1457.10320334, 1471.03216030]; votes 12128; rank 19 | 1,484.48100% of row best · rating · gpt-5.5-high; 95% CI [1478.10008380, 1490.85597001]; votes 20944; rank 9 |
| LMArena Search Arenasearch-2026-08-24-d25aabda0010 · arena_rating · leader | 1,204.3097% of row best · rating · claude-opus-4-8; 95% CI [1197.89112684, 1210.71069451]; votes 70998; rank 12 | 1,242.05100% of row best · rating · gpt-5.5-search; 95% CI [1236.73488085, 1247.37053078]; votes 89873; rank 3 |
| LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader | 1,452.6699% of row best · rating · claude-opus-4-8; 95% CI [1448.52490690, 1456.79817098]; votes 53446; rank 40 | 1,465.59100% of row best · rating · gpt-5.5; 95% CI [1461.82849712, 1469.35015015]; votes 66317; rank 31 |
| LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · statistical tie | 1,288.23100% of row best · rating · claude-opus-4-8; 95% CI [1281.27991800, 1295.18871241]; votes 15801; rank 25 | 1,294.19100% of row best · rating · gpt-5.5-high; 95% CI [1287.85384790, 1300.52893287]; votes 21960; rank 20 |
| LiveBench2026-06-25 · overall · leader | 81.1896% of row best · percent · claude-opus-4-8-max-effort · 24,171 output tokens / case | 84.54100% of row best · percent · gpt-5.5-xhigh · 11,355 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 | 82.6094% of row best · points · GPT-5.5 (xhigh) · 4,050 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above · 1 tie | 1 benchmark win | 6 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-5.5 |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Family | Claude 4 8 | Gpt 5 5 |
| Model | Claude Opus 4.8 | GPT-5.5 |
| Version | Claude Opus 4.8 | GPT-5.5 |
| Lifecycle | active | active |
| Released | 2026-05-28 | 2026-04-23 |
| Knowledge cutoff | 2026-01-01 | 2025-12-01 |
| 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, structured_outputs, tools |
Claude Opus 4.8 Capabilities
GPT-5.5 Capabilities
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Primary Evidence
Sources and Freshness
Questions
Claude Opus 4.8 vs GPT-5.5 FAQs
Is Claude Opus 4.8 or GPT-5.5 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Opus 4.8 and GPT-5.5, 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-5.5?+
Claude Opus 4.8 is $5.00 and GPT-5.5 is $5.00 per million tokens, so they are tied on this metric. Claude Opus 4.8 is $25.00 and GPT-5.5 is $30.00 per million tokens, so Claude Opus 4.8 is cheaper on this metric.
Which has a larger context window, Claude Opus 4.8 or GPT-5.5?+
GPT-5.5 has the larger sourced context window. Claude Opus 4.8 supports 1,000K and GPT-5.5 supports 1,050K.
Which performs better in benchmarks, Claude Opus 4.8 or GPT-5.5?+
GPT-5.5 leads the current overall benchmark count. The result uses 8 protocol-matched benchmarks from 3 publishers; it is not a universal quality score.
Can Claude Opus 4.8 or GPT-5.5 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Opus 4.8 is not marked open weight; GPT-5.5 is not marked open weight.
Can Claude Opus 4.8 and GPT-5.5 understand images?+
Claude Opus 4.8 is documented with image input; GPT-5.5 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Opus 4.8 or GPT-5.5?+
Neither has a larger sourced maximum output. Claude Opus 4.8 is 128K and GPT-5.5 is 128K.
Do Claude Opus 4.8 and GPT-5.5 support reasoning and tool use?+
Claude Opus 4.8: reasoning, tool calling, and image input. GPT-5.5: 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-5.5?+
Claude Opus 4.8 has 2 sourced provider routes; GPT-5.5 has 2, a tie.
Which offers better value, Claude Opus 4.8 or GPT-5.5?+
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.