Claude Sonnet 4.5 vs GPT-5 Pro
Benchmark Performance
Available Benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5 Pro |
|---|---|---|
| ARC-AGI-1verified-v1-b2e2a31b3d53 · verified_score · leader | 63.6791% of row best · percent · Claude Sonnet 4.5 (Thinking 32K) | 70.17100% of row best · percent · GPT-5 Pro |
| ARC-AGI-2verified-v2-326661568d5f · verified_score · leader | 13.6174% of row best · percent · Claude Sonnet 4.5 (Thinking 32K) | 18.33100% of row best · percent · GPT-5 Pro |
| Overall ResultCounted from the protocol-matched rows above | 0 benchmark wins | 2 benchmark winsOverall lead |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Technical Differences
Side-by-Side Facts
| Field | Claude Sonnet 4.5 | GPT-5 Pro |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Family | Claude 4 | Gpt 5 |
| Model | Claude Sonnet 4.5 | GPT-5 Pro |
| Version | Claude Sonnet 4.5 | GPT-5 Pro |
| Lifecycle | active | active |
| Released | 2025-09-29 | 2025-10-06 |
| Knowledge cutoff | 2025-01-01 | 2024-09-30 |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 200,000 | 400,000 |
| 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 |
15 comparable fields · 8 material differences · Pair passes the primary-source comparison gate
Claude Sonnet 4.5 Capabilities
GPT-5 Pro Capabilities
Internal Comparison Graph
Related Comparisons
| A | Pair | B | Context |
|---|---|---|---|
Claude Sonnet 4.5Anthropic | vs | Claude Sonnet 4.6Anthropic | family variantsimage, text |
GPT-5 MiniOpenAI | vs | GPT-5 ProOpenAI | family variantsimage, text |
GPT-5 ProOpenAI | vs | GPT-5.2OpenAI | family variantsimage, text |
GPT-5 ProOpenAI | vs | GPT-5.4 NanoOpenAI | family variantsimage, text |
Claude Opus 4.5Anthropic | vs | Claude Sonnet 4.5Anthropic | family variantsimage, text |
Claude Sonnet 4.5Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Sonnet 4.5Anthropic | vs | o3OpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | o3-proOpenAI | cross-developer peersimage, text |
GPT-5 ProOpenAI | vs | Grok 4.5xAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs |  Qwen3 VL FlashQwen | cross-developer peersimage, text |
GPT-5 ProOpenAI | vs | Qwen3 VL PlusQwen | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | GPT-5 NanoOpenAI | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Sonnet 4.5 vs GPT-5 Pro FAQs
Is Claude Sonnet 4.5 or GPT-5 Pro better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Sonnet 4.5 and GPT-5 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 GPT-5 Pro?+
Claude Sonnet 4.5 is $3.00 and GPT-5 Pro is $7.50 per million tokens, so Claude Sonnet 4.5 is cheaper on this metric. Claude Sonnet 4.5 is $15.00 and GPT-5 Pro is $60.00 per million tokens, so Claude Sonnet 4.5 is cheaper on this metric.
Which has a larger context window, Claude Sonnet 4.5 or GPT-5 Pro?+
GPT-5 Pro has the larger sourced context window. Claude Sonnet 4.5 supports 200,000 and GPT-5 Pro supports 400,000.
Which performs better in benchmarks, Claude Sonnet 4.5 or GPT-5 Pro?+
There is no overall benchmark winner: An overall winner requires at least two decisive benchmarks from at least two original publishers.
Can Claude Sonnet 4.5 or GPT-5 Pro be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Sonnet 4.5 is not marked open weight; GPT-5 Pro is not marked open weight.
Can Claude Sonnet 4.5 and GPT-5 Pro understand images?+
Claude Sonnet 4.5 is documented with image input; GPT-5 Pro is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Sonnet 4.5 or GPT-5 Pro?+
GPT-5 Pro has the larger sourced maximum output: Claude Sonnet 4.5 supports 64,000 and GPT-5 Pro supports 272,000 output tokens.
Do Claude Sonnet 4.5 and GPT-5 Pro support reasoning and tool use?+
Claude Sonnet 4.5: reasoning, tool calling, and image input. GPT-5 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 GPT-5 Pro?+
Claude Sonnet 4.5 has 1 sourced provider route; GPT-5 Pro has 2, so GPT-5 Pro has broader tracked availability.
Which offers better value, Claude Sonnet 4.5 or GPT-5 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.