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Compare Gemini 3.1 Pro and GPT-5.6 Sol: Multimodal vs Frontier Reasoning

Gemini 3.1 Pro vs GPT-5.6 Sol: which should I use?

Gemini 3.1 Pro leads in context window (2M tokens vs 1M) and native audio/video modalities, while GPT-5.6 Sol excels in autonomous multi-step software engineering and complex agentic logic. Verified 2026-09-07.

Verified 2026-09-07

Which tasks fit Gemini 3.1 Pro and GPT-5.6 Sol?

Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.

FactGemini 3.1 ProGPT-5.6 Sol
Best fitWhole-codebase, whole-document, or long-video analysis in a single request.Complex, multi-step professional and coding work where accuracy matters more than cost.
Reasoning modeAvailableAvailable

What does a Coding Agent workload cost with Gemini 3.1 Pro and GPT-5.6 Sol?

Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.

FactGemini 3.1 ProGPT-5.6 Sol
Coding Agent / task$0.06 (modeled) (winner)$0.12 (modeled)
Input / output rate$2.00 / $12.00 per M$4.00 / $20.00 per M

How fast are Gemini 3.1 Pro and GPT-5.6 Sol?

Only non-estimated benchmark results are shown as measured.

FactGemini 3.1 ProGPT-5.6 Sol
Measured throughput55 tokens/s (winner)44 tokens/s
Time to first token420 ms560 ms

How compatible are Gemini 3.1 Pro and GPT-5.6 Sol with APIs?

Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.

FactGemini 3.1 ProGPT-5.6 Sol
OpenAI SDKNot drop-inUsable
Request shapecontents/parts structure instead of messages; an OpenAI-compatible endpoint exists but only covers a subset of parameters.Canonical /chat/completions and /responses shape — every OpenAI-compatible provider on this site imitates it.
StreamingSSE (Gemini streamGenerateContent)SSE (OpenAI delta)

What are the privacy and retention policies for Gemini 3.1 Pro and GPT-5.6 Sol?

Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.

FactGemini 3.1 ProGPT-5.6 Sol
Provider says API data trains modelsNoNo
Published retention periodUnavailableUnavailable
Data residencyGlobal by default; Vertex AI offers selectable regional endpointsUS by default; EU data residency available on enterprise agreements

How much effort does it take to migrate between Gemini 3.1 Pro and GPT-5.6 Sol?

Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.

FactGemini 3.1 ProGPT-5.6 Sol
Move Gemini 3.1 Pro → GPT-5.6 Solconfig; 2 breaking parameter differencesTarget: GPT-5.6 Sol
Move GPT-5.6 Sol → Gemini 3.1 ProSource: GPT-5.6 Solcode-change; 1 breaking parameter difference
WhyKeep the `openai` SDK; change `baseURL` and the API key.contents/parts structure instead of messages; an OpenAI-compatible endpoint exists but only covers a subset of parameters.

Batch 63 · exact-pair decision contributions · verified 2026-09-07

Exact pair boundary: Google / OpenAI; model endpoint, 2M vs 1M context scale, audio/video vs text/image modalities, and reasoning costs must join. Requested models are gemini-3.1-pro and gpt-5.6-sol. Provider, rate, pricing, and task pages remain fact owners.

Context window scale (2M vs 1M) and modality admissibility gate

Frozen Batch 63 scenario board. Formula / deterministic rule: admissible = (audio_or_video ? Gemini : Both) && (context <= 1M ? Both : (context <= 2M ? Gemini : Excluded)) Boundary: Owns context scaling and modality gating between Gemini 3.1 Pro and GPT-5.6 Sol.

Frozen scenario / field IDPair, identity, host, surface, and evidence fieldsResultState
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m1-r1
text & image prompt (500K context)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=text & image prompt (500K context); task type; input context; video/audio required; Gemini eligible; Sol eligible; routing verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — text & image prompt (500K context) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m1-r2
video analysis prompt (100K context)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=video analysis prompt (100K context); task type; input context; video/audio required; Gemini eligible; Sol eligible; routing verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — video analysis prompt (100K context) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m1-r3
extreme text prompt (1.5M context)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=extreme text prompt (1.5M context); task type; input context; video/audio required; Gemini eligible; Sol eligible; routing verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — extreme text prompt (1.5M context) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m1-r4
multimodal audio call (250K context)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=multimodal audio call (250K context); task type; input context; video/audio required; Gemini eligible; Sol eligible; routing verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — multimodal audio call (250K context) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m1-r5
2M max context boundary test
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=2M max context boundary test; task type; input context; video/audio required; Gemini eligible; Sol eligible; routing verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 2M max context boundary test is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m1-r6
unsupported modality request
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=unsupported modality request; task type; input context; video/audio required; Gemini eligible; Sol eligible; routing verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — unsupported modality request has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: Google Gemini API model documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.

Promotional versus standard token billing crossover

Frozen Batch 63 scenario board. Formula / deterministic rule: cost_delta = sol_monthly_bill - gemini_monthly_bill; Sol promo ends 2026-11-21 Boundary: Owns pricing differential modeling taking into account OpenAI promotional schedules.

Frozen scenario / field IDPair, identity, host, surface, and evidence fieldsResultState
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m2-r1
10K queries under Sol promo rate ($4/$20)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=10K queries under Sol promo rate ($4/$20); query volume; Gemini spend; Sol promo spend; Sol standard spend; post-promo budget increase; cost verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 10K queries under Sol promo rate ($4/$20) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m2-r2
50K queries under Sol standard rate ($5/$30)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=50K queries under Sol standard rate ($5/$30); query volume; Gemini spend; Sol promo spend; Sol standard spend; post-promo budget increase; cost verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 50K queries under Sol standard rate ($5/$30) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m2-r3
100K high-volume document queries
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=100K high-volume document queries; query volume; Gemini spend; Sol promo spend; Sol standard spend; post-promo budget increase; cost verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 100K high-volume document queries is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m2-r4
prompt caching active (50% both)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=prompt caching active (50% both); query volume; Gemini spend; Sol promo spend; Sol standard spend; post-promo budget increase; cost verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — prompt caching active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m2-r5
batch queue active (50% both)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=batch queue active (50% both); query volume; Gemini spend; Sol promo spend; Sol standard spend; post-promo budget increase; cost verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — batch queue active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m2-r6
unresolved billing tariff schedule
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=unresolved billing tariff schedule; query volume; Gemini spend; Sol promo spend; Sol standard spend; post-promo budget increase; cost verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — unresolved billing tariff schedule has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: OpenAI API pricing; verification date 2026-09-07. Missing or conflicting joins fail closed.

Dual-routing canary and enterprise defect error budget

Frozen Batch 63 scenario board. Formula / deterministic rule: break_even_accuracy = (sol_cost / gemini_cost) - 1; defect loss saved justifies Sol spend Boundary: Owns accuracy-versus-cost trade-off modeling without speculative assertions.

Frozen scenario / field IDPair, identity, host, surface, and evidence fieldsResultState
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m3-r1
zero defect cost (raw cost comparison)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=zero defect cost (raw cost comparison); scenario; Gemini monthly spend; Sol monthly spend; cost delta; required accuracy uplift; financial recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — zero defect cost (raw cost comparison) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m3-r2
low defect penalty ($10 per error)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=low defect penalty ($10 per error); scenario; Gemini monthly spend; Sol monthly spend; cost delta; required accuracy uplift; financial recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — low defect penalty ($10 per error) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m3-r3
medium defect penalty ($50 per error)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=medium defect penalty ($50 per error); scenario; Gemini monthly spend; Sol monthly spend; cost delta; required accuracy uplift; financial recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — medium defect penalty ($50 per error) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m3-r4
high-stakes defect penalty ($200 per error)
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=high-stakes defect penalty ($200 per error); scenario; Gemini monthly spend; Sol monthly spend; cost delta; required accuracy uplift; financial recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — high-stakes defect penalty ($200 per error) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m3-r5
dual-routing 10% canary audit
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=dual-routing 10% canary audit; scenario; Gemini monthly spend; Sol monthly spend; cost delta; required accuracy uplift; financial recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — dual-routing 10% canary audit is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch63-gemini-3-1-pro-vs-gpt-5-6-sol-m3-r6
unresolved defect valuation
pair=gemini-3.1-pro vs gpt-5.6-sol; provider=Google / OpenAI; hostA=generativelanguage.googleapis.com; hostB=api.openai.com; surfaceA=Google AI Studio / Vertex AI; surfaceB=OpenAI Responses API; requested/effective IDs=gemini-3.1-pro,gpt-5.6-sol; scenario=unresolved defect valuation; scenario; Gemini monthly spend; Sol monthly spend; cost delta; required accuracy uplift; financial recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — unresolved defect valuation has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: OpenAI model documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.

Method and limitations: formulas are deterministic; observed and assumed inputs are labeled; no missing provider, host, account, region, realm, alias, snapshot, revision, weight, artifact, control, tool, modality, workload, rate-period, timestamp, or result is transferred. Run the gemini-3-1-pro-vs-gpt-5-6-sol Batch 63 scenario →

How do Gemini 3.1 Pro and GPT-5.6 Sol compare on specs?

Gemini 3.1 ProGPT-5.6 Sol
Price (input)$2.00/M$4.00/M
Price (output)$12.00/M$20.00/M
Blended price$4.50/M$8.00/M
Context window2,000,000 tokens1,000,000 tokens
Max output64,000 tokens128,000 tokens
Modalitiestext, vision, audiotext, vision
Reasoning modeYesYes
Released2026-022026-06
Speed55 t/s44 t/s

How much do Gemini 3.1 Pro and GPT-5.6 Sol cost at scale?

Tokens / monthGemini 3.1 ProGPT-5.6 SolDelta
1,000,000$4.50$8.00$3.50 (1.8×)
10,000,000$45.00$80.00$35.00 (1.8×)
100,000,000$450.00$800.00$350.00 (1.8×)

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.

Choose GPT-5.6 Sol if…

  • Strongest OpenAI model for agentic, long-horizon coding
  • Deep reasoning mode for multi-step planning
  • Native vision input and 1M context
  • Complex, multi-step professional and coding work where accuracy matters more than cost.

Run this exact matchup right now

Send the same prompt to Gemini 3.1 Pro and GPT-5.6 Sol side by side and see the outputs yourself.

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What are common questions about Gemini 3.1 Pro and GPT-5.6 Sol?

Is Gemini 3.1 Pro cheaper than GPT-5.6 Sol?

Gemini 3.1 Pro is cheaper, at $4.50 per million blended tokens vs $8.00 for GPT-5.6 Sol.

Which has the bigger context window, Gemini 3.1 Pro or GPT-5.6 Sol?

Gemini 3.1 Pro has the larger context window: 2,000,000 tokens vs 1,000,000.

Can Gemini 3.1 Pro replace GPT-5.6 Sol for coding?

Both are viable for coding. Largest context window of any current model (2M tokens) (Gemini 3.1 Pro) vs Strongest OpenAI model for agentic, long-horizon coding (GPT-5.6 Sol) — pick based on which strength matters more for your workload.

Which is faster, Gemini 3.1 Pro or GPT-5.6 Sol?

Gemini 3.1 Pro is faster: 55 t/s vs 44 t/s, measured on our speed benchmarks.

Neither of these? See Gemini 3.1 Pro alternatives or GPT-5.6 Sol alternatives.

What related comparisons help choose between Gemini 3.1 Pro and GPT-5.6 Sol?

Gemini 3.1 Pro pricingGPT-5.6 Sol pricingvs Claude Opus 4.8vs Claude Sonnet 5vs DeepSeek V4 Provs Grok 4.3Premium model tests

Pricing verified 2026-04-06. Specs verified 2026-08-14.