Compare / head-to-head
Claude Opus 4.8vsGPT-5.5
GPT-5.5 leads 5 of 10 shared benchmarks. Claude Opus 4.8 is 1.2x cheaper per token. Both offer a 1M-token context window.
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
4 – 5
GPT-5.5 leads · 1 tied
Cheaper per token
Claude Opus 4.8
1.2x cheaper, input + output
Larger context
Tie
both 1M tokens
Provider uptime (30d)
100% · 95.2941%
Anthropic · OpenAI
Claude Opus 4.8
Anthropic · released 2026-05-28
textvision
Quality
Benchmark matrix
10 shared · 6 only Claude Opus 4.8 · 11 only GPT-5.5| Benchmark | Claude Opus 4.8 | GPT-5.5 | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 10 | ||||
| GPQA Diamond | 93.6% ↗ | 90.7% ↗epoch | +2.9 pt | Claude Opus 4.8 |
| AIME 2026 | 100% ↗matharena ⚠ | 100% ↗matharena ⚠ | 0 | Tie |
| LMArena Elo | 1452.7 ↗ | 1465.6 ↗ | -12.9 | GPT-5.5 |
| BrowseComp | 84.3% ↗ | 84.4% ↗ | -0.1 pt | GPT-5.5 |
| FrontierMath Tier 4 v2 (Epoch AI run) | 56.1% ↗epoch | 72.5% ↗epoch | -16.4 pt | GPT-5.5 |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 80% ↗epoch | 85.3% ↗epoch | -5.3 pt | GPT-5.5 |
| OSWorld-Verified | 83.4% ↗ | 78.7% ↗ | +4.7 pt | Claude Opus 4.8 |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 98.3% ↗epoch | 84.4% ↗epoch | +13.9 pt | Claude Opus 4.8 |
| SimpleQA Verified | 53% ↗epoch | 63% ↗epoch | -10 pt | GPT-5.5 |
| SWE-Bench Pro | 69.2% ↗ | 58.6% ↗ | +10.6 pt | Claude Opus 4.8 |
| Only Claude Opus 4.8 reports · 6 | ||||
| SWE-bench Verified | 88.6% ↗ | not reported | — | — |
| Humanity's Last Exam (no tools) | 49.8% ↗ | not reported | — | — |
| Humanity's Last Exam (with tools) | 57.9% ↗ | not reported | — | — |
| SWE-bench Multilingual | 84.4% ↗ | not reported | — | — |
| SWE-bench Multimodal | 38.4% ↗ | not reported | — | — |
| Terminal-Bench 2.1 | 74.6% ↗ | not reported | — | — |
| Only GPT-5.5 reports · 11 | ||||
| ARC-AGI-1 (Verified) | not reported | 95% ↗ | — | — |
| ARC-AGI-2 (Verified) | not reported | 85% ↗ | — | — |
| FrontierMath Tier 1-3 | not reported | 51.7% ↗ | — | — |
| FrontierMath Tier 4 | not reported | 35.4% ↗ | — | — |
| GDPval (wins or ties) | not reported | 84.9% ↗ | — | — |
| MCP Atlas | not reported | 75.3% ↗ | — | — |
| MMMU-Pro (no tools) | not reported | 81.2% ↗ | — | — |
| MMMU-Pro (with tools) | not reported | 83.2% ↗ | — | — |
| Tau2-bench Telecom | not reported | 98% ↗ | — | — |
| Terminal-Bench 2.0 | not reported | 82.7% ↗ | — | — |
| Toolathlon | not reported | 55.6% ↗ | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Claude Opus 4.8 minus GPT-5.5 in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | Claude Opus 4.8 | GPT-5.5 | Edge |
|---|---|---|---|
| Context window | 1M tokens | 1M tokens | Tie |
| Max output | 128K tokens | 128K tokens | Tie |
| Input price / 1M | $5 ↗ | $5 ↗ | Tie |
| Output price / 1M | $25 ↗ | $30 ↗ | Claude Opus 4.8 |
| Cached input / 1M | $0.5 ↗ | $0.5 ↗ | Tie |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $30 | $35 | Claude Opus 4.8 |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-05-28 | 2026-04-23 | — |
| Cited benchmark scores | 17 | 21 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Claude Opus 4.8 vs …
Models sharing the most benchmarksMore matchups
GPT-5.5 vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Claude Opus 4.8 and GPT-5.5 on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.