Model comparison

GPT-5.6 Sol vs Gemini 3.1 Pro

GPT-5.6 Sol costs $4.00 / $20.00 and Gemini 3.1 Pro $2.00 / $12.00 per 1M input / output tokens. Both accept about 1M tokens of context, text, images and files.

GPT-5.6 Sol: sources list different prices. We use $4.00 / $20.00; OpenRouter shows $2.00 / $10.00. See every source.

OpenAI

GPT-5.6 Sol

Released Jul 9, 2026 · gpt-5.6-sol

Google

Gemini 3.1 Pro

Released Feb 19, 2026 · gemini-3.1-pro

Which one to choose

Picked by a published rule, not by an editor. Scenarios without data are left out.

Everyday requests

Gemini 3.1 Pro

$0.014 vs $0.008 for 1,000 input and 500 output tokens.

Long prompts

Gemini 3.1 Pro

A 500K-token prompt with a 2K-token answer costs $4.06 on GPT-5.6 Sol and $2.04 on Gemini 3.1 Pro.

Context window

About the same

GPT-5.6 Sol: 1.05M tokens; Gemini 3.1 Pro: 1.05M. Differences under 10% count as a tie.

Mixed inputs

Gemini 3.1 Pro

GPT-5.6 Sol: Text, Images, Files (PDF). Gemini 3.1 Pro: Text, Images, Files (PDF), Audio, Video.

How the verdicts are calculated
  • Everyday requests: lower cost for 1,000 input + 500 output tokens at standard rates.
  • Long prompts: lower cost for a 500K-token prompt and 2K-token answer, including long-context surcharges.
  • Context window: bigger window wins; differences under 10% count as a tie.
  • Mixed inputs: more input types accepted; a tie is not shown until multimodal benchmark scores are collected.

Not shown yet

  • Coding: needs SWE-bench Verified scores
  • Speed: needs independent output-speed measurements
  • Privacy: needs data-retention and training-use policies

Side by side

The better value in each row is marked. Observed from LiteLLM and OpenRouter, checked against vendor pricing pages.

SpecGPT-5.6 SolGemini 3.1 Pro
Input priceper 1M tokens$4.00$2.00 (better)
Output priceper 1M tokens$20.00$12.00 (better)
Cached inputper 1M tokens$0.40$0.20 (better)
Typical request1,000 input + 500 output tokens$0.014$0.008 (better)
Long-prompt pricingCompared on a 500K-token prompt$8.00 / $30.00 above 272K tokens$4.00 / $18.00 above 200K tokens (better)
Batch priceinput / output per 1M tokens$2.00 / $10.00
Context window1.05M tokens1.05M tokens
Max output128K tokens (better)66K tokens
Knowledge cutoffFeb 2026 (better)Jan 2025
Input typesText, Images, Files (PDF)Text, Images, Files (PDF), Audio, Video (better)
ReasoningAdjustable effortAdjustable effort
Tool useYesYes
Structured output (JSON)YesYes
BenchmarksGPQA Diamond, SWE-bench Verified, AIME 2025, LMArenaNot collected yetNot collected yet
Output speedtokens per secondNot collected yetNot collected yet