Claude 3.5 Sonnet vs o4
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
Claude 3.5 Sonnet specs · o4 specs- PriceClaude 3.5 Sonnet
Claude 3.5 Sonnet publishes pricing ($15.00 / 1M output tokens) while o4 does not.
- Context windowTie
Both ship a 200K-token context window.
- BenchmarksTie
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.
- ModalitiesTie
Both handle text, vision.
- OpennessTie
Both are closed-weight, API-only.
On balance Claude 3.5 Sonnet edges ahead, winning 1 of 5 categories against o4's 0. Claude 3.5 Sonnet publishes pricing ($15.00 / 1M output tokens) while o4 does not. Both ship a 200K-token context window.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. Both target the same set of modalities (text, vision), so the deciding factors are price, context, and raw quality. Both are closed-weight, API-only.
o4 is the newer of the two, released 14 months after Claude 3.5 Sonnet, which usually means a more recent knowledge cutoff and updated safety post-training. Claude 3.5 Sonnet is usually picked for coding llm and code review workloads, while o4 sees more deployments in reasoning and math. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.
Side-by-side specs
| Spec | Claude 3.5 Sonnet | o4 |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | Oct 2024 | Dec 2025 |
| Modalities | text, vision | text, vision |
| Context window | 200K tokens | 200K tokens |
| Max output | , | , |
| Input · 1M | $3.00 / 1M tokens | Pricing not published |
| Output · 1M | $15.00 / 1M tokens | Pricing not published |
| Knowledge cutoff | , | , |
| Open weights | No | No |
| API available | Yes | Yes |
Pricing at scale
What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.
- Light usage, 100k in / 50k out per day$31.50 vs ,
- Heavy usage, 1M in / 500k out per day$315 vs ,
- RAG workload, 5M in / 200k out per day$540 vs ,
Light usage, 100k in / 50k out per day: pricing not directly comparable (one or both models are missing public per-token rates). Heavy usage, 1M in / 500k out per day: pricing not directly comparable (one or both models are missing public per-token rates). RAG workload, 5M in / 200k out per day: pricing not directly comparable (one or both models are missing public per-token rates).
Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.
- Claude 3.5 Sonnet$1.05
- o4Pricing unavailable
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
- HumanEval92.0
Claude 3.5 Sonnet fits when…
- Mature and battle-tested
- Strong code
o4 fits when…
- Exceptional performance on hard math and reasoning benchmarks
- Good at multi-step planning and verification
- Strong scientific reasoning
Consider Claude Opus 4.7
Anthropic's mid-2026 flagship, ahead on SWE-bench, agent reliability, and writing quality.
Frequently asked
Is Claude 3.5 Sonnet or o4 cheaper?
Per-token pricing isn't published for at least one of these models, check each model's spec page for current rates.Which has the larger context window?
Both Claude 3.5 Sonnet and o4 ship a 200K-token context window.Is Claude 3.5 Sonnet or o4 better for coding?
Both Claude 3.5 Sonnet and o4 are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.Are either of these models open source?
Neither model ships open weights, both are accessible only via their respective providers' APIs.When were Claude 3.5 Sonnet and o4 released?
Claude 3.5 Sonnet was released by Anthropic on 2024-10-22. o4 was released by OpenAI on 2025-12-15.
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