GPT-5.4 vs Gemini 3.1 Pro

Side-by-side comparison of GPT-5.4 (OpenAI) 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 GPT-5.4 Gemini 3.1 Pro
Provider OpenAI Google
Model id gpt-5.4 gemini-3.1-pro
Input price (per 1M tokens) $2.50 $2.00
Output price (per 1M tokens) $15.00 $12.00
Context window 400,000 1,048,576
Output speed (tokens/sec) ~100 ~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 GPT-5.4 Gemini 3.1 Pro Cheaper
Short question + answer 50 150 $0.002375 $0.001900 Gemini 3.1 Pro
Code review on one file 500 1,500 $0.023750 $0.019000 Gemini 3.1 Pro
Long document summary 5,000 500 $0.020000 $0.016000 Gemini 3.1 Pro
Heavy reasoning task 2,000 8,000 $0.125000 $0.100000 Gemini 3.1 Pro
Full codebase analysis 50,000 10,000 $0.275000 $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 GPT-5.4 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
  • tasks needing a larger context window — gemini-3.1-pro fits 3x more tokens than gpt-5.4

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 GPT-5.4 to Gemini 3.1 Pro

# Before
model = "gpt-5.4"

# After
model = "gemini-3.1-pro"

If the providers differ (OpenAI 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 →