Claude 3.5 Sonnet v2 vs o3-pro
Claude 3.5 Sonnet v2 (2025) and o3-pro (2025) are frontier reasoning models from Anthropic and OpenAI. Claude 3.5 Sonnet v2 ships a 200k-token context window, while o3-pro ships a 200k-token context window. On pricing, Claude 3.5 Sonnet v2 costs $6/1M input tokens versus $20/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Claude 3.5 Sonnet v2 is ~233% cheaper at $6/1M; pay for o3-pro only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Claude 3.5 Sonnet v2 | o3-pro |
|---|---|---|
| Best for | multimodal apps and provider-routed production | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | RAG, Long context, and Vision | Coding, RAG, and Agents |
| Context window | 200k | 200k |
| Cheapest output | $30/1M tokens | $80/1M tokens |
| Provider routes | 2 tracked | 3 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Claude 3.5 Sonnet v2 has the lower cheapest tracked output price at $30/1M tokens.
- Local decision data tags Claude 3.5 Sonnet v2 for RAG, Long context, and Vision.
- o3-pro has broader tracked provider coverage for fallback and procurement flexibility.
- o3-pro uniquely exposes Reasoning, Function calling, and Tool use in local model data.
- Local decision data tags o3-pro 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 3.5 Sonnet v2
$12,300
Cheapest tracked route/tier: AWS Bedrock
o3-pro
$36,000
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $23,700. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Claude 3.5 Sonnet v2 and o3-pro; plan for SDK, billing, or endpoint changes.
- o3-pro is $50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- o3-pro adds Reasoning, Function calling, and Tool use in local capability data.
- No overlapping tracked provider route is sourced for o3-pro and Claude 3.5 Sonnet v2; plan for SDK, billing, or endpoint changes.
- Claude 3.5 Sonnet v2 is $50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-12-01 | 2025-06-10 |
| Context window | 200k | 200k |
| Parameters | — | — |
| Architecture | - | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2024-04 | 2025-08 |
Pricing and availability
| Pricing attribute | Claude 3.5 Sonnet v2 | o3-pro |
|---|---|---|
| Input price | $6/1M tokens | $20/1M tokens |
| Output price | $30/1M tokens | $80/1M tokens |
| Providers |
Capabilities
| Capability | Claude 3.5 Sonnet v2 | o3-pro |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | Yes |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Deep dive
The capability footprint differs most on reasoning mode: o3-pro, function calling: o3-pro, tool use: o3-pro, and code execution: o3-pro. Both models share vision, multimodal input, and structured outputs, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Claude 3.5 Sonnet v2 lists $6/1M input and $30/1M output tokens on the cheapest tracked provider, while o3-pro lists $20/1M input and $80/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Claude 3.5 Sonnet v2 lower by about $24.80 per million blended tokens. Availability is 2 providers versus 3, so concentration risk also matters.
Choose Claude 3.5 Sonnet v2 when vision-heavy evaluation and lower input-token cost are central to the workload. Choose o3-pro when coding workflow support and broader provider choice 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.
FAQ
Which has a larger context window, Claude 3.5 Sonnet v2 or o3-pro?
Claude 3.5 Sonnet v2 supports 200k tokens, while o3-pro supports 200k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Claude 3.5 Sonnet v2 or o3-pro?
Claude 3.5 Sonnet v2 is cheaper on tracked token pricing. Claude 3.5 Sonnet v2 costs $6/1M input and $30/1M output tokens. o3-pro costs $20/1M input and $80/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Claude 3.5 Sonnet v2 or o3-pro open source?
Claude 3.5 Sonnet v2 is listed under Proprietary. o3-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 3.5 Sonnet v2 or o3-pro?
Both Claude 3.5 Sonnet v2 and o3-pro expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, Claude 3.5 Sonnet v2 or o3-pro?
Both Claude 3.5 Sonnet v2 and o3-pro expose multimodal input. 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 3.5 Sonnet v2 and o3-pro?
Claude 3.5 Sonnet v2 is available on AWS Bedrock and Anthropic. o3-pro is available on OpenRouter, OpenAI API, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.