ModelRefs / Claude 3.5 Sonnet vs o3 Pro
Claude 3.5 Sonnet vs o3 Pro
Claude 3.5 Sonnet vs o3 Pro: side-by-side benchmarks, pricing, context windows, coding ability and deployment. Pick the right model for your stack.
Overview
Claude 3.5 Sonnet: Claude 3.5 Sonnet is Anthropic's mid-2024 balanced model, the release that introduced computer use and anchored Anthropic's agentic-coding positioning for its generation across a 200,000-token context window. It is now retired: Anthropic deprecated both the claude-3-5-sonnet-20240620 and claude-3-5-sonnet-20241022 snapshots on 13 August 2025 and retired them on 28 October 2025 on Anthropic-operated platforms, naming Claude Sonnet 5.5 as the replacement.
o3 Pro: o3 Pro is OpenAI's highest-capability reasoning model, applying extended compute at inference time to solve complex scientific, mathematical, and programming problems. It achieved the highest published scores on ARC-AGI-2 and competitive programming benchmarks at its June 2025 release.
Context window: Claude 3.5 Sonnet accepts up to 200,000 tokens, o3 Pro up to 200,000. Confirm the limit for your specific deployment channel before relying on it.
Claude 3.5 Sonnet vs o3 Pro at a glance
| Attribute | Claude 3.5 Sonnet | o3 Pro |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | 2024-06-20 | 2025-06-10 |
| Context window | 200,000 tokens | 200,000 tokens |
| Input price | $3/M tokens | $20/M tokens |
| Output price | $15/M tokens | $80/M tokens |
| Licence | Proprietary | Proprietary |
| Self-hostable | No, hosted only | No, hosted only |
| Modalities | text, vision | text, vision |
Where they differ most
- Coding: Claude 3.5 Sonnet 49%, o3 Pro 85%. o3 Pro 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 3.5 Sonnet vs o3 Pro.
Frequently asked questions
Which is better, Claude 3.5 Sonnet or o3 Pro?
Claude 3.5 Sonnet and o3 Pro target different workloads — see the benchmark and pricing tables for a side-by-side answer.
Is Claude 3.5 Sonnet cheaper than o3 Pro?
Compare $0.00300 vs $0.0200 on this page.