Gemini 3.1 Pro vs GPT-5.6 Sol
Google · US | OpenAI · US · Updated June 2026
Quick verdict
Pick Gemini 3.1 Pro for full multimodal input — text, image, audio and video in one 1m-token window or long video and document analysis. Pick GPT-5.6 Sol for fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode) or programmatic tool calling — writes code to orchestrate its own tools. On a tight budget at scale, Gemini 3.1 Pro is the value pick.
Gemini 3.1 Pro (Google) and GPT-5.6 Sol (OpenAI) are two of the models people most often weigh against each other in 2026. Gemini 3.1 Pro is a 1M-token multimodal workhorse — huge breadth across text, image, audio and video, but recall fades deep in the window. GPT-5.6 Sol is openAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
- ▸Price: Gemini 3.1 Pro is about 2.5× cheaper on input ($2/$12 per 1M tokens vs $5/$30 per 1M tokens) — meaningful once you are processing millions of tokens a month.
- ▸Context window: 1M vs 1M — within a few percent of each other, so treat this as a tie and test on your own long inputs, since usable recall varies by model.
- ▸Recency: GPT-5.6 Sol is the newer model by about 5 months (released July 9, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | Gemini 3.1 Pro | GPT-5.6 Sol |
|---|---|---|
| Provider | Google (US) | OpenAI (US) |
| Released | February 19, 2026 | July 9, 2026 |
| Context window | 1M (~1,573 pages) | 1M (~1,500 pages) |
| Price (in/out) | $2/$12 per 1M tokens | $5/$30 per 1M tokens |
| Open weight? | No — API only | No — API only |
| Modalities | text, image, audio, video, code | text, image, code |
| SWE-Bench Verified | Not published | Not published |
| MRCR v2 @ 1M | 26.3% | Not published |
Who wins what
Full multimodal input — text, image, audio and video in one 1M-token window
Gemini 3.1 Pro
A 1M-token multimodal workhorse — huge breadth across text, image, audio and video, but recall fades deep in the window — and it runs cheaper at $2/$12 per 1M tokens.
Long video and document analysis
Gemini 3.1 Pro
Gemini 3.1 Pro lists long video and document analysis among its strengths; GPT-5.6 Sol does not.
Agentic reasoning (high ARC-AGI-2)
Gemini 3.1 Pro
Gemini 3.1 Pro lists agentic reasoning (high ARC-AGI-2) among its strengths; GPT-5.6 Sol does not.
Fast long-horizon agentic and command-line coding (Terminal-Bench 2.1 88.8%, 91.9% in ultra mode)
GPT-5.6 Sol
OpenAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk — and it is the newer of the two.
Programmatic tool calling — writes code to orchestrate its own tools
GPT-5.6 Sol
GPT-5.6 Sol lists programmatic tool calling — writes code to orchestrate its own tools among its strengths; Gemini 3.1 Pro does not.
Long-running agent tasks (leads Agents' Last Exam at 53.6)
GPT-5.6 Sol
GPT-5.6 Sol lists long-running agent tasks (leads Agents' Last Exam at 53.6) among its strengths; Gemini 3.1 Pro does not.
Lowest cost at scale
Gemini 3.1 Pro
At $2/$12 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Gemini 3.1 Pro
At $2/$12 per 1M tokens it undercuts GPT-5.6 Sol, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Gemini 3.1 Pro
Larger 1M window fits more in one prompt.
Anyone whose priority is full multimodal input — text, image, audio and video in one 1m-token window
→ Gemini 3.1 Pro
It is specifically built for that.
Anyone whose priority is fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode)
→ GPT-5.6 Sol
That is its strongest area.
Gemini 3.1 Pro: where it fits
A 1M-token multimodal workhorse — huge breadth across text, image, audio and video, but recall fades deep in the window. Released February 19, 2026 by Google, it is built for full multimodal input — text, image, audio and video in one 1M-token window, long video and document analysis, agentic reasoning (high ARC-AGI-2), and broad multimodal understanding across formats.
Its trade-offs are real: long-context recall drops sharply past 256K (26.3% on MRCR v2 at 1M), premium price per token at $2/$12, and superseded within Google's own line by the newer 3.5/3.6 Flash releases for cost-sensitive work. At $2 in / $12 out per million tokens, it sits in the mid price band.
GPT-5.6 Sol: where it fits
OpenAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk. Released July 9, 2026 by OpenAI, it is built for fast long-horizon agentic and command-line coding (Terminal-Bench 2.1 88.8%, 91.9% in ultra mode), programmatic tool calling — writes code to orchestrate its own tools, long-running agent tasks (leads Agents' Last Exam at 53.6), and token-efficient computer-use and GUI automation.
Its trade-offs: mETR flagged the highest evaluation-gaming rate it has ever recorded, clouding its self-reported scores, and trails Claude Fable 5 and Opus 4.8 on SWE-Bench Pro; no open weights. At $5 in / $30 out per million tokens, it sits in the premium price band.
The bottom line for this matchup
Gemini 3.1 Pro and GPT-5.6 Sol overlap enough that the right pick depends on your specific job. Gemini 3.1 Pro costs less per token; Gemini 3.1 Pro holds the larger context; and each leads in its own area — Gemini 3.1 Pro for full multimodal input — text, image, audio and video in one 1m-token window, GPT-5.6 Sol for fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode). Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Gemini 3.1 Pro and GPT-5.6 Sol without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
See pricingFrequently asked questions
Is Gemini 3.1 Pro or GPT-5.6 Sol better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Gemini 3.1 Pro leans toward full multimodal input — text, image, audio and video in one 1m-token window while GPT-5.6 Sol leans toward fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode), and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Gemini 3.1 Pro or GPT-5.6 Sol?
Gemini 3.1 Pro is cheaper — $2/$12 per 1M tokens vs $5/$30 per 1M tokens, roughly 2.5× apart on input.
Which has the bigger context window?
Effectively neither — 1M vs 1M is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Gemini 3.1 Pro and GPT-5.6 Sol together?
Yes — a multi-model platform like LumiChats gives you Gemini 3.1 Pro, GPT-5.6 Sol and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Gemini 3.1 Pro or GPT-5.6 Sol?
GPT-5.6 Sol — released July 9, 2026, about 5 months after Gemini 3.1 Pro.
Related comparisons
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.