ModelRefs / Claude 3 Opus vs o3
Claude 3 Opus vs o3
Claude 3 Opus vs o3: side-by-side benchmarks, pricing, context windows, coding ability and deployment. Pick the right model for your stack.
Overview
Claude 3 Opus: Claude 3 Opus is Anthropic's February 2024 frontier model and the most capable of the original Claude 3 family, accepting text and image input across a 200,000-token context window. The claude-3-opus-20240229 snapshot was deprecated on 30 June 2025 and retired on Anthropic-operated platforms on 5 January 2026, with Claude Opus 4.8 named as its replacement.
o3: o3 is OpenAI's April 2025 reasoning model, applying deliberate chain-of-thought computation at inference time to mathematics, science and competitive programming tasks, and the release that brought OpenAI's scalable test-time compute approach to its production API. OpenAI has since deprecated it, scheduling the o3-2025-04-16 snapshot to shut down on 11 December 2026 with gpt-5.6-sol as the replacement.
Context window: Claude 3 Opus accepts up to 200,000 tokens, o3 up to 200,000. Confirm the limit for your specific deployment channel before relying on it.
Claude 3 Opus vs o3 at a glance
| Attribute | Claude 3 Opus | o3 |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | 2024-02-29 | 2025-04-16 |
| Context window | 200,000 tokens | 200,000 tokens |
| Input price | $15/M tokens | $10/M tokens |
| Output price | $75/M tokens | $40/M tokens |
| Licence | Proprietary | Proprietary |
| Self-hostable | No, hosted only | No, hosted only |
| Modalities | text, vision | text, vision |
Benchmarks reported for both
| Benchmark | Claude 3 Opus | o3 | Reported |
|---|---|---|---|
| GPQA Diamond (accuracy) | 50.4 | 82.8 | 2024-03-04 |
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
- Reasoning: Claude 3 Opus 38%, o3 86%. o3 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 Claude 3 Opus vs o3.
Frequently asked questions
Which is better, Claude 3 Opus or o3?
Claude 3 Opus and o3 target different workloads — see the benchmark and pricing tables for a side-by-side answer.
Is Claude 3 Opus cheaper than o3?
Compare $0.0150 vs $0.0100 on this page.