Claude Opus 4.8 vs Gemini 3.5 Flash
Claude Opus 4.8 (2026) and Gemini 3.5 Flash (2026) are frontier-tier reasoning models from Anthropic and Google DeepMind. Claude Opus 4.8 ships a 1m-token context window, while Gemini 3.5 Flash ships a 1m-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads. It focuses on practical selection signals rather than broad model-family marketing.
Claude Opus 4.8 is safer overall; choose Gemini 3.5 Flash when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | Claude Opus 4.8 | Gemini 3.5 Flash |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 1m |
| 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 Computer use and Parallel agents in local model data.
- Local decision data tags Claude Opus 4.8 for Coding, RAG, and Agents.
- Local decision data tags Gemini 3.5 Flash for Coding, RAG, and Agents.
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 Flash
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 Flash; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Computer use and Parallel agents before moving production traffic.
- No overlapping tracked provider route is sourced for Gemini 3.5 Flash and Claude Opus 4.8; plan for SDK, billing, or endpoint changes.
- Claude Opus 4.8 adds Computer use and Parallel agents in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-05-28 | 2026-05-19 |
| Context window | 1m | 1m |
| Parameters | — | — |
| Architecture | Decoder Only | 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 Flash |
|---|---|---|
| Input price | $5/1M tokens | - |
| Output price | $25/1M tokens | - |
| Providers | - |
Capabilities
| Capability | Claude Opus 4.8 | Gemini 3.5 Flash |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| 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 capability footprint is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
Pricing coverage is uneven: Claude Opus 4.8 has $5/1M input tokens and Gemini 3.5 Flash has no token price sourced yet. Provider availability is 6 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Claude Opus 4.8 when coding workflow support and broader provider choice are central to the workload. Choose Gemini 3.5 Flash when coding workflow support are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Which has a larger context window, Claude Opus 4.8 or Gemini 3.5 Flash?
Claude Opus 4.8 supports 1m tokens, while Gemini 3.5 Flash 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 Flash open source?
Claude Opus 4.8 is listed under Proprietary. Gemini 3.5 Flash 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 Flash?
Both Claude Opus 4.8 and Gemini 3.5 Flash 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 Flash?
Both Claude Opus 4.8 and Gemini 3.5 Flash 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 Flash?
Both Claude Opus 4.8 and Gemini 3.5 Flash 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 Flash?
Claude Opus 4.8 is available on Anthropic, AWS Bedrock, GCP Vertex AI, Microsoft Foundry, and OpenRouter. Gemini 3.5 Flash is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-17. Data sourced from public model cards and provider documentation.