ModelRefs / GPT-5 vs Claude Sonnet 4.5
GPT-5 vs Claude Sonnet 4.5
GPT-5 vs Claude Sonnet 4.5: side-by-side benchmarks, pricing, context windows, coding ability and deployment. Pick the right model for your stack.
Overview
Claude Sonnet 4.5: Claude Sonnet 4.5 is Anthropic's balanced frontier model, designed for complex reasoning, coding, and agentic tasks while maintaining production-grade speed. It builds on the Claude 4 family's emphasis on honesty and reduced hallucination rates.
GPT-5: GPT-5 is OpenAI's August 2025 reasoning model for coding, reasoning, and agentic tasks. The API model supports text input and output, image input, configurable reasoning effort, and an immutable gpt-5-2025-08-07 snapshot; OpenAI now classifies it as a previous-generation model.
Context window: Claude Sonnet 4.5 accepts up to 200,000 tokens, GPT-5 up to 400,000. Confirm the limit for your specific deployment channel before relying on it.
Claude Sonnet 4.5 vs GPT-5 at a glance
| Attribute | Claude Sonnet 4.5 | GPT-5 |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | 2025-09-29 | 2025-08-07 |
| Context window | 200,000 tokens | 400,000 tokens |
| Input price | $3/M tokens | $1.25/M tokens |
| Output price | $15/M tokens | $10/M tokens |
| Licence | Proprietary | Proprietary |
| Self-hostable | No, hosted only | No, hosted only |
| Modalities | text, vision | text, vision |
Benchmarks reported for both
| Benchmark | Claude Sonnet 4.5 | GPT-5 | Reported |
|---|---|---|---|
| SWE-Bench Verified (resolved) | 77.2 | 74.9 | 2025-09-29 / 2025-08-07 |
Each row compares the same benchmark, the same reported metric, and the same task set. Scores are as published by their cited sources on the dates shown. Different runs still use different harnesses and prompts, so treat these as directional evidence rather than a head-to-head result.
Where they differ most
- Agentic: Claude Sonnet 4.5 66%, GPT-5 89%. GPT-5 leads on this dimension.
- Cost Efficiency: Claude Sonnet 4.5 37%, GPT-5 47%. GPT-5 leads on this dimension.
- Coding: Claude Sonnet 4.5 77%, GPT-5 81%. GPT-5 leads on this dimension.
Capability scores are ModelRefs' own derived signals, not vendor claims or benchmark results. Validate against your own workload before relying on them.
Continue your research
Use these connected ModelRefs sections to compare alternatives, inspect implementation paths, and review the evidence and governance boundaries relevant to GPT-5 vs Claude Sonnet 4.5.
Frequently asked questions
Which is better, GPT-5 or Claude Sonnet 4.5?
GPT-5 and Claude Sonnet 4.5 target different workloads — see the benchmark and pricing tables for a side-by-side answer.
Is GPT-5 cheaper than Claude Sonnet 4.5?
Compare $0.00125 vs $0.00300 on this page.