Claude Sonnet 5.5 vs Gemini 3.1 Pro — Price, Context, and Capability Compared
Claude Sonnet 5.5 vs Gemini 3.1 Pro: which should I use?
Claude Sonnet 5.5 and Gemini 3.1 Pro are priced within a few percent of each other. Gemini 3.1 Pro has the larger context window (2,000,000 tokens). Default to Claude Sonnet 5.5 unless you specifically need Gemini 3.1 Pro's edge.
Where can you find price, speed, and task evidence for Claude Sonnet 5.5 and Gemini 3.1 Pro?
Which tasks fit Claude Sonnet 5.5 and Gemini 3.1 Pro?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Claude Sonnet 5.5 | Gemini 3.1 Pro |
|---|---|---|
| Best fit | Well-scoped everyday coding and knowledge work at the best speed-intelligence balance. | Whole-codebase, whole-document, or long-video analysis in a single request. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with Claude Sonnet 5.5 and Gemini 3.1 Pro?
Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.
| Fact | Claude Sonnet 5.5 | Gemini 3.1 Pro |
|---|---|---|
| Coding Agent / task | $0.06 (modeled) (winner) | $0.06 (modeled) |
| Input / output rate | $2.00 / $10.00 per M | $2.00 / $12.00 per M |
How fast are Claude Sonnet 5.5 and Gemini 3.1 Pro?
Only non-estimated benchmark results are shown as measured.
| Fact | Claude Sonnet 5.5 | Gemini 3.1 Pro |
|---|---|---|
| Measured throughput | Unavailable | 55 tokens/s |
| Time to first token | Unavailable | 420 ms |
How compatible are Claude Sonnet 5.5 and Gemini 3.1 Pro with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Claude Sonnet 5.5 | Gemini 3.1 Pro |
|---|---|---|
| OpenAI SDK | Not drop-in | Not drop-in |
| Request shape | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. | contents/parts structure instead of messages; an OpenAI-compatible endpoint exists but only covers a subset of parameters. |
| Streaming | SSE (Anthropic content-block events) | SSE (Gemini streamGenerateContent) |
What are the privacy and retention policies for Claude Sonnet 5.5 and Gemini 3.1 Pro?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Claude Sonnet 5.5 | Gemini 3.1 Pro |
|---|---|---|
| Provider says API data trains models | No | No |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | Global by default; Vertex AI offers selectable regional endpoints |
How much effort does it take to migrate between Claude Sonnet 5.5 and Gemini 3.1 Pro?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Claude Sonnet 5.5 | Gemini 3.1 Pro |
|---|---|---|
| Move Claude Sonnet 5.5 → Gemini 3.1 Pro | code-change; 1 breaking parameter difference | Target: Gemini 3.1 Pro |
| Move Gemini 3.1 Pro → Claude Sonnet 5.5 | Source: Gemini 3.1 Pro | code-change; 7 breaking parameter differences |
| Why | contents/parts structure instead of messages; an OpenAI-compatible endpoint exists but only covers a subset of parameters. | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. |
How do Claude Sonnet 5.5 and Gemini 3.1 Pro compare on specs?
| Claude Sonnet 5.5 | Gemini 3.1 Pro | |
|---|---|---|
| Price (input) | $2.00/M | $2.00/M |
| Price (output) | $10.00/M ✓ | $12.00/M |
| Blended price | $4.00/M ✓ | $4.50/M |
| Context window | 1,000,000 tokens | 2,000,000 tokens ✓ |
| Max output | 128,000 tokens ✓ | 64,000 tokens |
| Modalities | text, vision | text, vision, audio |
| Reasoning mode | Yes | Yes |
| Released | 2026-09 | 2026-02 |
| Speed | Not measured | 55 t/s |
How much do Claude Sonnet 5.5 and Gemini 3.1 Pro cost at scale?
| Tokens / month | Claude Sonnet 5.5 | Gemini 3.1 Pro | Delta |
|---|---|---|---|
| 1,000,000 | $4.00 | $4.50 | $0.50 (1.1×) |
| 10,000,000 | $40.00 | $45.00 | $5.00 (1.1×) |
| 100,000,000 | $400.00 | $450.00 | $50.00 (1.1×) |
Choose Claude Sonnet 5.5 if…
- ✓30% faster output than Sonnet 5
- ✓Up to 30% lower cost per task at the same token price
- ✓Beats Opus 5.5 on agentic coding evals
- ✓Well-scoped everyday coding and knowledge work at the best speed-intelligence balance.
Choose Gemini 3.1 Pro if…
- ✓Largest context window of any current model (2M tokens)
- ✓Native audio and video understanding
- ✓Google Search grounding
- ✓Whole-codebase, whole-document, or long-video analysis in a single request.
Run this exact matchup right now
Send the same prompt to Claude Sonnet 5.5 and Gemini 3.1 Pro side by side and see the outputs yourself.
Try Claude Sonnet 5.5 vs Gemini 3.1 Pro FreeWhat are common questions about Claude Sonnet 5.5 and Gemini 3.1 Pro?
Is Claude Sonnet 5.5 cheaper than Gemini 3.1 Pro?
Claude Sonnet 5.5 is cheaper, at $4.00 per million blended tokens vs $4.50 for Gemini 3.1 Pro.
Which has the bigger context window, Claude Sonnet 5.5 or Gemini 3.1 Pro?
Gemini 3.1 Pro has the larger context window: 2,000,000 tokens vs 1,000,000.
Can Claude Sonnet 5.5 replace Gemini 3.1 Pro for coding?
Both are viable for coding. 30% faster output than Sonnet 5 (Claude Sonnet 5.5) vs Largest context window of any current model (2M tokens) (Gemini 3.1 Pro) — pick based on which strength matters more for your workload.
Neither of these? See Claude Sonnet 5.5 alternatives or Gemini 3.1 Pro alternatives.
What related comparisons help choose between Claude Sonnet 5.5 and Gemini 3.1 Pro?
Pricing verified 2026-04-06. Specs verified 2026-08-14.