Compare / head-to-head
Claude Opus 5.5vs
Gemini 3.8 Flash
Claude Opus 5.5 and Gemini 3.8 Flash do not yet share a public benchmark, so quality cannot be compared apples-to-apples. Gemini 3.8 Flash is 5.3x cheaper per token. Gemini 3.8 Flash has the larger context window (1.0M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0
no overlap yet
Cheaper per token
Gemini 3.8 Flash
5.3x cheaper, input + output
Larger context
Gemini 3.8 Flash
1.0M tokens
Providers
2 providers
Anthropic · Google
Claude Opus 5.5
Anthropic · released 2026-09-22
textvision
Gemini 3.8 Flash
Google · released 2026-09-02
textvisionaudio
Quality
Benchmark matrix
0 shared · 9 only Claude Opus 5.5 · 15 only Gemini 3.8 Flash| Benchmark | Claude Opus 5.5 | Gemini 3.8 Flash | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 0 | ||||
| No public benchmark is reported for both models yet. | ||||
| Only Claude Opus 5.5 reports · 9 | ||||
| AutomationBench 1.0.6 | 40% ↗ | not reported | — | — |
| Chartography (with tools) | 89% ↗ | not reported | — | — |
| CursorBench 4.0 | 57.8% ↗ | not reported | — | — |
| FrontierCode v1.1 (Main) | 54.4% ↗ | not reported | — | — |
| GDPval-AA v2.1 | 1846 ↗ | not reported | — | — |
| Humanity's Last Exam (with tools) | 67.7% ↗ | not reported | — | — |
| OSWorld 2.0 (partial) | 81.8% ↗ | not reported | — | — |
| Terminal-Bench 4.0 | 66.4% ↗ | not reported | — | — |
| Terminal-Bench Science 0.1 | 58.7% ↗ | not reported | — | — |
| Only Gemini 3.8 Flash reports · 15 | ||||
| GPQA Diamond | not reported | 95.3% ↗ | — | — |
| CharXiv Reasoning (no tools) | not reported | 86.2% ↗ | — | — |
| DeepSWE v1.1 | not reported | 73.7% ↗ | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | not reported | 22% ↗epoch | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | not reported | 68.4% ↗epoch | — | — |
| GDPVal-AA v2 | not reported | 1545 ↗ | — | — |
| Harvey's Legal Agent Benchmark | not reported | 10% ↗ | — | — |
| HLE-Verified | not reported | 54.9% ↗ | — | — |
| LABBench2 | not reported | 86.2% ↗ | — | — |
| OSWorld-2.0 | not reported | 59% ↗ | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | not reported | 98.9% ↗epoch | — | — |
| SimpleQA Verified | not reported | 69.7% ↗epoch | — | — |
| Terminal-bench 2.1 | not reported | 89.4% ↗ | — | — |
| Terminal-bench 4.0 | not reported | 19.1% ↗ | — | — |
| Vals Finance Agent v2 | not reported | 61.4% ↗ | — | — |
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 5.5 minus Gemini 3.8 Flash 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 5.5 | Gemini 3.8 Flash | Edge |
|---|---|---|---|
| Context window | 1M tokens | 1.0M tokens | Gemini 3.8 Flash |
| Max output | 128K tokens | 66K tokens | Claude Opus 5.5 |
| Input price / 1M | $4 ↗ | $0.75 ↗ | Gemini 3.8 Flash |
| Output price / 1M | $20 ↗ | $3.75 ↗ | Gemini 3.8 Flash |
| Cached input / 1M | $0.2 ↗ | $0.075 ↗ | Gemini 3.8 Flash |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $24 | $4.5 | Gemini 3.8 Flash |
| Modalities | text · vision | text · vision · audio | Gemini 3.8 Flash |
| Released | 2026-09-22 | 2026-09-02 | — |
| Cited benchmark scores | 9 | 16 | — |
Reliability
Provider status
Live from /statusMore matchups
Claude Opus 5.5 vs …
Models sharing the most benchmarksMore matchups
Gemini 3.8 Flash vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Claude Opus 5.5 and Gemini 3.8 Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.