Claude Opus 4.8 vs Gemini 3.5 Flash: Benchmarks, Pricing & Capabilities Compared
TL;DR — Claude Opus 4.8 wins for reasoning · Gemini 3.5 Flash wins for cost.
Claude Opus 4.8 Anthropic
- Released
- 2026-05-28
- Context window
- 1M tokens
- Input price
- $6.25 / Mtok
- Output price
- $25.00 / Mtok
Gemini 3.5 Flash Google
- Released
- 2026-05-19
- Context window
- 1M tokens
- Input price
- $1.50 / Mtok
- Output price
- $9.00 / Mtok
Benchmark comparison
| Benchmark | Claude Opus 4.8 | Gemini 3.5 Flash |
|---|---|---|
| AA Intelligence Index | 61.4 ✓ | 43.3 |
| GPQA Diamond | 92.0% ✓ | 82.8% |
| HLE | 45.7% ✓ | 23.1% |
| IF-Bench | 62.2% ✓ | 47.3% |
| LiveCodeBench Reasoning | 67.7% ✓ | 53.3% |
| SciCode | 53.5% ✓ | 48.8% |
| TAU2-bench | 94.4% ✓ | 58.8% |
| TerminalBench-Hard | 58.3% ✓ | 46.2% |
Pricing comparison
| Metric | Claude Opus 4.8 | Gemini 3.5 Flash |
|---|---|---|
| Input ($/Mtok) | $6.25 | $1.50 |
| Output ($/Mtok) | $25.00 | $9.00 |
| Cached input ($/Mtok) | — | — |
| Cost per 1M-token roundtrip (1M in + 1M out) | $31.25 | $10.50 |
Context window & modalities
| Attribute | Claude Opus 4.8 | Gemini 3.5 Flash |
|---|---|---|
| Context window | 1M tokens | 1M tokens |
| Input modalities | text, image | text, image, audio, video |
| Output modalities | text | text |
| Knowledge cutoff | — | — |
Verdict by use case
Coding
Insufficient data
Basis: SWE-bench
No shared coding benchmark.
Reasoning
→ Claude Opus 4.8
Basis: GPQA Diamond
Claude Opus 4.8 92% vs Gemini 3.5 Flash 82.8% on GPQA Diamond.
Math
Insufficient data
Basis: MATH / AIME
No shared math benchmark.
Long context
Tie
Basis: Context window
Claude Opus 4.8 1M tokens vs Gemini 3.5 Flash 1M tokens.
Cost
→ Gemini 3.5 Flash
Basis: Input $/Mtok
Claude Opus 4.8 $6.25/Mtok vs Gemini 3.5 Flash $1.5/Mtok input.
Changelog & releases
Claude Opus 4.8
Released 2026-05-28
Gemini 3.5 Flash
Released 2026-05-19