Claude Opus 4.5 vs Gemini 3.5 Flash
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Claude Opus 4.5
Anthropic · Nov 2025
The November 2025 Opus that cut flagship pricing 3x to $5/$25 and was the first model past 80% on SWE-bench Verified.
Gemini 3.5 Flash
Google · May 2026
Google's I/O 2026 headliner: near-Pro intelligence at Flash speed, 78.8% on SWE-bench Verified with full multimodal input.
The verdict
Claude Opus 4.5 wins 1 of the 1 benchmarks these models share, against 0 for Gemini 3.5 Flash. Gemini 3.5 Flash is about 3.0x cheaper per blended million tokens (3:1 input:output mix). Gemini 3.5 Flash also takes 1M of context versus 200K for Claude Opus 4.5.
Benchmark head-to-head 1–0
Specs & pricing
| Claude Opus 4.5 | Gemini 3.5 Flash | |
|---|---|---|
| modhub Index | — | — |
| Input price / 1M | $5 | $1.5 |
| Output price / 1M | $25 | $9 |
| Context window | 200K | 1M |
| Max output | 64K | 66K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image, audio, video |
| Knowledge cutoff | Mar 2025 | Feb 2026 |
| Released | Nov 2025 | May 2026 |
| Example monthly cost* | $87.50 | $28.50 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Claude Opus 4.5 or Gemini 3.5 Flash?
- Claude Opus 4.5 wins 1 of the 1 benchmarks these models share, against 0 for Gemini 3.5 Flash. Gemini 3.5 Flash is about 3.0x cheaper per blended million tokens (3:1 input:output mix). Gemini 3.5 Flash also takes 1M of context versus 200K for Claude Opus 4.5.
- Which is cheaper, Claude Opus 4.5 or Gemini 3.5 Flash?
- Claude Opus 4.5 costs $5/$25 per million input/output tokens, while Gemini 3.5 Flash costs $1.5/$9. For a typical workload of 10M input and 1.5M output tokens per month, that's $87.50 versus $28.50.
- Which model is better for coding, Claude Opus 4.5 or Gemini 3.5 Flash?
- On SWE-bench Verified — the standard agentic-coding benchmark — Claude Opus 4.5 scores 80.9% versus 78.8% for Gemini 3.5 Flash, making Claude Opus 4.5 the stronger pick for coding agents.
More comparisons
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