ModelRefs / Claude 3.5 Sonnet vs o3
Claude 3.5 Sonnet vs o3
Claude 3.5 Sonnet vs o3: 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: 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 3.5 Sonnet accepts up to 200,000 tokens, o3 up to 200,000. Confirm the limit for your specific deployment channel before relying on it.
Claude 3.5 Sonnet vs o3 at a glance
| Attribute | Claude 3.5 Sonnet | o3 |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | 2024-06-20 | 2025-04-16 |
| Context window | 200,000 tokens | 200,000 tokens |
| Input price | $3/M tokens | $10/M tokens |
| Output price | $15/M tokens | $40/M tokens |
| Licence | Proprietary | Proprietary |
| Self-hostable | No, hosted only | No, hosted only |
| Modalities | text, vision | text, vision |
Where they differ most
- Cost Efficiency: Claude 3.5 Sonnet 37%, o3 13%. Claude 3.5 Sonnet 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.
Frequently asked questions
Which is better, Claude 3.5 Sonnet or o3?
Claude 3.5 Sonnet and o3 target different workloads — see the benchmark and pricing tables for a side-by-side answer.
Is Claude 3.5 Sonnet cheaper than o3?
Compare $0.00300 vs $0.0100 on this page.