Claude 3.5 Sonnet vs Gemini 3 Flash
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
- PriceClaude 3.5 Sonnet
Claude 3.5 Sonnet publishes pricing ($15.00 / 1M output tokens) while Gemini 3 Flash does not.
- Context windowGemini 3 Flash
Gemini 3 Flash accepts 1.0M tokens vs 200K, 5.2× the room for long documents and codebases.
- BenchmarksTie
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.
- ModalitiesGemini 3 Flash
Gemini 3 Flash supports 4 modalities (text, vision, audio, video) vs 2 for Claude 3.5 Sonnet.
- OpennessTie
Both are closed-weight, API-only.
On balance Gemini 3 Flash edges ahead, winning 2 of 5 categories against Claude 3.5 Sonnet's 1. Claude 3.5 Sonnet publishes pricing ($15.00 / 1M output tokens) while Gemini 3 Flash does not. Gemini 3 Flash accepts 1.0M tokens vs 200K, 5.2× the room for long documents and codebases.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. They differ in modality coverage, Claude 3.5 Sonnet handles text, vision while Gemini 3 Flash handles text, vision, audio, video, which can be the deciding factor before you even look at benchmarks. Both are closed-weight, API-only.
Gemini 3 Flash 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 Gemini 3 Flash sees more deployments in rag and summarization. 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 | Gemini 3 Flash |
|---|---|---|
| Provider | Anthropic | |
| Released | Oct 2024 | Dec 2025 |
| Modalities | text, vision | text, vision, audio, video |
| Context window | 200K tokens | 1.0M tokens |
| Max output | , | 65.5K tokens |
| Input · 1M | $3.00 / 1M tokens | Pricing not published |
| Output · 1M | $15.00 / 1M tokens | Pricing not published |
| Knowledge cutoff | , | 2025-01 |
| 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
- Gemini 3 FlashPricing 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
Gemini 3 Flash fits when…
- 1M-token context at mid-tier price
- Very fast, good for interactive UX
- Strong vision support
- Long-context tasks, handles 1.0M tokens vs 200K for Claude 3.5 Sonnet.
- Multimodal needs covering audio, video.
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 Gemini 3 Flash 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?
Gemini 3 Flash accepts 1.0M tokens vs 200K for Claude 3.5 Sonnet.Is Claude 3.5 Sonnet or Gemini 3 Flash better for coding?
Both Claude 3.5 Sonnet and Gemini 3 Flash 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 Gemini 3 Flash released?
Claude 3.5 Sonnet was released by Anthropic on 2024-10-22. Gemini 3 Flash was released by Google on 2025-12-09.
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