Claude Opus 4.5 vs OpenAI o3
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Claude Opus 4.5
Anthropic · Nov 2025
The November 2025 Opus that cut flagship pricing 3x to $5/$25 and was the first model past 80% on SWE-bench Verified.
OpenAI o3
68.9OpenAI · Apr 2025
OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.
The verdict
Claude Opus 4.5 wins 2 of the 2 benchmarks these models share, against 0 for OpenAI o3. OpenAI o3 is about 2.9x cheaper per blended million tokens (3:1 input:output mix).
Benchmark head-to-head 2–0
Specs & pricing
| Claude Opus 4.5 | OpenAI o3 | |
|---|---|---|
| modhub Index | — | 68.9 |
| Input price / 1M | $5 | $2 |
| Output price / 1M | $25 | $8 |
| Context window | 200K | 200K |
| Max output | 64K | 100K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Mar 2025 | May 2024 |
| Released | Nov 2025 | Apr 2025 |
| Example monthly cost* | $87.50 | $32.00 |
* 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 Opus 4.5 or OpenAI o3?
- Claude Opus 4.5 wins 2 of the 2 benchmarks these models share, against 0 for OpenAI o3. OpenAI o3 is about 2.9x cheaper per blended million tokens (3:1 input:output mix).
- Which is cheaper, Claude Opus 4.5 or OpenAI o3?
- Claude Opus 4.5 costs $5/$25 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $87.50 versus $32.00.
- Which model is better for coding, Claude Opus 4.5 or OpenAI o3?
- On SWE-bench Verified — the standard agentic-coding benchmark — Claude Opus 4.5 scores 80.9% versus 69.1% for OpenAI o3, making Claude Opus 4.5 the stronger pick for coding agents.