Claude Sonnet 4.5 vs GPT-4o
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Claude Sonnet 4.5
65.5Anthropic · Sep 2025
The model that made 30-hour autonomous coding sessions real — 77.2% SWE-bench Verified and a 1M-token context beta at $3/$15.
GPT-4o
OpenAI · May 2024
The 2024 omni-modal classic with native audio in and out; superseded at the frontier but still everywhere in production.
The verdict
Claude Sonnet 4.5 wins 3 of the 3 benchmarks these models share, against 0 for GPT-4o. GPT-4o is about 1.4x cheaper per blended million tokens (3:1 input:output mix). Claude Sonnet 4.5 also takes 200K of context versus 128K for GPT-4o.
Benchmark head-to-head 3–0
Specs & pricing
| Claude Sonnet 4.5 | GPT-4o | |
|---|---|---|
| modhub Index | 65.5 | — |
| Input price / 1M | $3 | $2.5 |
| Output price / 1M | $15 | $10 |
| Context window | 200K | 128K |
| Max output | 64K | 16K |
| Open weights | no | no |
| Reasoning model | yes | no |
| Multimodal input | text, image | text, image, audio |
| Knowledge cutoff | Jan 2025 | Oct 2023 |
| Released | Sep 2025 | May 2024 |
| Example monthly cost* | $52.50 | $40.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Claude Sonnet 4.5 or GPT-4o?
- Claude Sonnet 4.5 wins 3 of the 3 benchmarks these models share, against 0 for GPT-4o. GPT-4o is about 1.4x cheaper per blended million tokens (3:1 input:output mix). Claude Sonnet 4.5 also takes 200K of context versus 128K for GPT-4o.
- Which is cheaper, Claude Sonnet 4.5 or GPT-4o?
- Claude Sonnet 4.5 costs $3/$15 per million input/output tokens, while GPT-4o costs $2.5/$10. For a typical workload of 10M input and 1.5M output tokens per month, that's $52.50 versus $40.00.
- Which model is better for coding, Claude Sonnet 4.5 or GPT-4o?
- On SWE-bench Verified — the standard agentic-coding benchmark — Claude Sonnet 4.5 scores 77.2% versus 33.2% for GPT-4o, making Claude Sonnet 4.5 the stronger pick for coding agents.