Claude Sonnet 4.6 vs Gemini 3.1 Pro

Side-by-side comparison of Claude Sonnet 4.6 (Anthropic) and Gemini 3.1 Pro (Google). Exact API pricing per million tokens, context windows, output speed, and total cost on real-world prompts.

Specifications

Spec Claude Sonnet 4.6 Gemini 3.1 Pro
Provider Anthropic Google
Model id claude-sonnet-4.6 gemini-3.1-pro
Input price (per 1M tokens) $3.00 $2.00
Output price (per 1M tokens) $15.00 $12.00
Context window 1,000,000 1,048,576
Output speed (tokens/sec) ~90 ~90

Cost on real prompts

Total cost = (input tokens × input price) + (output tokens × output price). Numbers below use the exact pricing tables published by each provider.

Scenario Input Output Claude Sonnet 4.6 Gemini 3.1 Pro Cheaper
Short question + answer 50 150 $0.002400 $0.001900 Gemini 3.1 Pro
Code review on one file 500 1,500 $0.024000 $0.019000 Gemini 3.1 Pro
Long document summary 5,000 500 $0.022500 $0.016000 Gemini 3.1 Pro
Heavy reasoning task 2,000 8,000 $0.126000 $0.100000 Gemini 3.1 Pro
Full codebase analysis 50,000 10,000 $0.300000 $0.220000 Gemini 3.1 Pro

Want the exact cost for your prompt instead of these examples? Open the cost calculator pre-loaded with both models →

When to pick which

Heuristics derived from the spec table above. Always validate on your own prompts before committing — these are starting points, not verdicts.

Pick Claude Sonnet 4.6 for

No clear advantage on the data points we measure. Compare on your actual prompts.

Pick Gemini 3.1 Pro for

  • input-heavy workloads — gemini-3.1-pro is cheaper per input token

Switching between them

For most use cases, switching providers means updating the model id and the request shape if the providers differ. Within the same provider, it's usually a single-line change.

From Claude Sonnet 4.6 to Gemini 3.1 Pro

# Before
model = "claude-sonnet-4.6"

# After
model = "gemini-3.1-pro"

If the providers differ (Anthropic vs Google), you'll also need to swap the SDK / endpoint URL. Cross-provider migrations usually take 30 minutes to a few hours depending on how many features (streaming, function calling, tool use) you depend on.

Calculate cost on your own prompt

The examples above use generic input/output ratios. For an exact comparison, paste your real prompt into the calculator — it counts tokens with the right tokenizer for each model and shows side-by-side cost.

Open the calculator with both models →