Claude Opus 4.8 vs Gemini 3.5 Pro
Gemini 3.5 Pro and Claude Opus 4.8 are the Google-versus-Anthropic flagship comparison to watch before Gemini 3.5 Pro reaches general availability. Gemini 3.5 Pro is tracked as limited Vertex AI enterprise preview with a confirmed 2M-token context window and no confirmed public pricing. Claude Opus 4.8 is already available, priced, and benchmarked across coding-agent and reasoning rows.
Use Claude Opus 4.8 for production agentic coding today: it has tracked provider routes, pricing, and public rows for SWE-bench Verified, SWE-bench Pro, Terminal-Bench 2.1, and GPQA Diamond. Track Gemini 3.5 Pro for long-context and multimodal workloads where the 2M-token window may beat Opus 4.8's 1M window, but do not budget or migrate production traffic until Google confirms GA pricing and public API details.
Decision scorecard
Local evidence first| Signal | Claude Opus 4.8 | Gemini 3.5 Pro |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and long-context analysis |
| Decision fit | Coding, RAG, and Agents | Long context and Vision |
| Context window | 1m | 2m |
| Cheapest output | $25/1M tokens | - |
| Provider routes | 6 tracked | 0 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Claude Opus 4.8 has broader tracked provider coverage for fallback and procurement flexibility.
- Claude Opus 4.8 uniquely exposes Function calling, Tool use, and Structured outputs in local model data.
- Local decision data tags Claude Opus 4.8 for Coding, RAG, and Agents.
- Gemini 3.5 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags Gemini 3.5 Pro for Long context and Vision.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Opus 4.8
$10,250
Cheapest tracked route/tier: Anthropic
Gemini 3.5 Pro
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Claude Opus 4.8 and Gemini 3.5 Pro; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Function calling, Tool use, and Structured outputs before moving production traffic.
- No overlapping tracked provider route is sourced for Gemini 3.5 Pro and Claude Opus 4.8; plan for SDK, billing, or endpoint changes.
- Claude Opus 4.8 adds Function calling, Tool use, and Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-05-28 | 2026-05-19 |
| Context window | 1m | 2m |
| Parameters | — | — |
| Architecture | Decoder Only | - |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2026-01 | - |
Pricing and availability
| Pricing attribute | Claude Opus 4.8 | Gemini 3.5 Pro |
|---|---|---|
| Input price | $5/1M tokens | - |
| Output price | $25/1M tokens | - |
| Providers | - |
Capabilities
| Capability | Claude Opus 4.8 | Gemini 3.5 Pro |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | Yes | No |
| Parallel agents | Yes | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Deep dive
The first split is availability. Claude Opus 4.8 is a callable production model across tracked Anthropic routes. Gemini 3.5 Pro is still marked preview in the seed, so this page is a wait-or-adopt comparison rather than a live migration recommendation.
Context is Gemini's strongest sourced advantage. The local model data tracks Gemini 3.5 Pro at 2M tokens versus Claude Opus 4.8 at 1M tokens, which matters for large repositories, long transcripts, document sets, and multimodal context packs that are too large for normal frontier windows.
Benchmark evidence is asymmetric. Claude Opus 4.8 has public coding-agent and reasoning rows in the seed. Gemini 3.5 Pro does not yet have comparable public benchmark rows, so the page should not treat it as a quality leader before Google publishes GA evidence.
Pricing is intentionally blank for Gemini 3.5 Pro. Do not copy speculative reported prices into planning; use Claude Opus 4.8 for current cost estimates and revisit this page when Google publishes official Gemini 3.5 Pro pricing.
FAQ
Which has a larger context window, Claude Opus 4.8 or Gemini 3.5 Pro?
Gemini 3.5 Pro supports 2m tokens, while Claude Opus 4.8 supports 1m tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Claude Opus 4.8 or Gemini 3.5 Pro open source?
Claude Opus 4.8 is listed under Proprietary. Gemini 3.5 Pro is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Claude Opus 4.8 or Gemini 3.5 Pro?
Both Claude Opus 4.8 and Gemini 3.5 Pro expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Claude Opus 4.8 or Gemini 3.5 Pro?
Both Claude Opus 4.8 and Gemini 3.5 Pro expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for reasoning mode, Claude Opus 4.8 or Gemini 3.5 Pro?
Both Claude Opus 4.8 and Gemini 3.5 Pro expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Claude Opus 4.8 and Gemini 3.5 Pro?
Claude Opus 4.8 is available on Anthropic, AWS Bedrock, GCP Vertex AI, Microsoft Foundry, and OpenRouter. Gemini 3.5 Pro is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-20. Data sourced from public model cards and provider documentation.