Claude Sonnet 4.5 vs o3-pro
Benchmark Performance
Available Benchmarks
Technical Differences
Side-by-Side Facts
| Field | Claude Sonnet 4.5 | o3-pro |
|---|---|---|
| Developer | Anthropic | Openai |
| Family | Claude 4 | O3 |
| Model | Claude Sonnet 4.5 | o3-pro |
| Version | Claude Sonnet 4.5 | o3-pro |
| Lifecycle | active | active |
| Released | 2025-09-29 | 2025-06-10 |
| Knowledge cutoff | 2025-01-01 | 2024-06-01 |
| Input modalities | Unknown | Text, Image |
| Output modalities | Unknown | Text |
| Context window | 200,000 | 200,000 |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Anthropic (Standard) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, structured_outputs, tools | chat, generation, reasoning, structured_outputs, tools |
13 comparable fields · 7 material differences · Interactive comparison only; indexing gate not met
Claude Sonnet 4.5 Capabilities
o3-pro Capabilities
Internal Comparison Graph
Related Comparisons
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|---|---|---|---|
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Primary Evidence
Sources and Freshness
Questions
Claude Sonnet 4.5 vs o3-pro FAQs
Is Claude Sonnet 4.5 or o3-pro better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Sonnet 4.5 and o3-pro, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Sonnet 4.5 or o3-pro?+
Only o3-pro has a directly sourced input price: $20.00 per million tokens. Only o3-pro has a directly sourced output price: $80.00 per million tokens.
Which has a larger context window, Claude Sonnet 4.5 or o3-pro?+
Neither model has a larger sourced context window in this comparison. Claude Sonnet 4.5 is 200,000 and o3-pro is 200,000.
Which performs better in benchmarks, Claude Sonnet 4.5 or o3-pro?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can Claude Sonnet 4.5 or o3-pro be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Sonnet 4.5 is not marked open weight; o3-pro is not marked open weight.
Can Claude Sonnet 4.5 and o3-pro understand images?+
Claude Sonnet 4.5 is not documented with image input; o3-pro is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Sonnet 4.5 or o3-pro?+
o3-pro has the larger sourced maximum output: Claude Sonnet 4.5 supports 64,000 and o3-pro supports 100,000 output tokens.
Do Claude Sonnet 4.5 and o3-pro support reasoning and tool use?+
Claude Sonnet 4.5: reasoning and tool calling. o3-pro: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Sonnet 4.5 or o3-pro?+
Claude Sonnet 4.5 has 1 sourced provider route; o3-pro has 2, so o3-pro has broader tracked availability.
Which offers better value, Claude Sonnet 4.5 or o3-pro?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.