Gemini 3 Flash Preview vs GPT-5.6 Sol Pro
Gemini 3 Flash Preview costs 6.7x less per output token than GPT-5.6 Sol Pro ($3.00 vs $20.00 per million). Updated October 21, 2026; 6 benchmarks have a result for both.
Gemini 3 Flash Preview or GPT-5.6 Sol Pro: which to pick
Only Gemini 3 Flash Preview has a coding score, 43.7 on the Vibe Coding Index; GPT-5.6 Sol Pro has none, so the two cannot be ranked on coding.
Pick GPT-5.6 Sol Pro for a larger context window (1.05M against 1.05M tokens) and work measured by WeirdML or SimpleBench, where it leads.
- Shared results
- 6
- Gemini 3 Flash Preview only
- 65
- GPT-5.6 Sol Pro only
- 1
- Like-for-like categories
- 4 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Only Gemini 3 Flash Preview has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
No call
Only Gemini 3 Flash Preview has a AA Intelligence Index result, 26.3.
Directional only
Reasoning
GPQA Diamond
No call
Only Gemini 3 Flash Preview has a GPQA Diamond result, 87.9%.
Directional only
Math
AIME
No call
Only Gemini 3 Flash Preview has a AIME result, 95.6%.
Directional only
Knowledge
MMLU Pro
No call
Only Gemini 3 Flash Preview has a MMLU Pro result, 88.6%.
Directional only
Web design
Design Arena: websites
No call
Only Gemini 3 Flash Preview has a Design Arena: websites result, 1196.
Directional only
Long documents
Listed context window
GPT-5.6 Sol Pro
GPT-5.6 Sol Pro takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 3 Flash Preview
Gemini 3 Flash Preview $0.0020, GPT-5.6 Sol Pro $0.014 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3 Flash Preview has the number, $0.37.
Directional only
At a glance
- Coding index
- Gemini 3 Flash Preview 43.7 from 2 benchmarks, GPT-5.6 Sol Pro not benchmarked.
- Widest category
- Math, 63.4 points apart on average over 1 shared benchmark.
- Widest single gap
- FrontierMath, tier 4: Gemini 3 Flash Preview 17.1% against GPT-5.6 Sol Pro 80.5%, 63.4 points apart on a 0 to 100 scale.
- Output price
- Gemini 3 Flash Preview $3.00 against GPT-5.6 Sol Pro $20.00 per million output tokens, 6.7x apart.
- Context window
- Gemini 3 Flash Preview takes 1.05M tokens, GPT-5.6 Sol Pro 1.05M.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Gemini 3 Flash Preview | Bars | GPT-5.6 Sol Pro | Ties |
|---|---|---|---|---|
| Coding | 0 | 1 | ||
| Reasoning | 0 | 2 | ||
| Math | 0 | 1 | ||
| General | 0 | 2 | ||
| All shared boards | 0 | 6 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index01
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| SWE-bench Verified | 75.8% | Not measured | Only Gemini 3 Flash Preview measured |
| LiveCodeBench (Vals AI) | 85.6% | Not measured | Only Gemini 3 Flash Preview measured |
| SWE-bench Verified (Vals AI) | 75.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Vibe Code Bench (Vals AI) | 20.2% | Not measured | Only Gemini 3 Flash Preview measured |
| Code migration (Vals AI) | 6.4% | Not measured | Only Gemini 3 Flash Preview measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Terminal-Bench 2.1 (Vals AI) | 53.9% | Not measured | Only Gemini 3 Flash Preview measured |
| LiveCodeBench (Artificial Analysis run) | 90.8% | Not measured | Only Gemini 3 Flash Preview measured |
| Terminal-Bench Hard (Artificial Analysis run) | 38.6% | Not measured | Only Gemini 3 Flash Preview measured |
| Terminal-Bench | 64.3% | Not measured | Only Gemini 3 Flash Preview measured |
| GSO-Bench | 9.8% | Not measured | Only Gemini 3 Flash Preview measured |
| WeirdML | 61.6% | 89.4% | GPT-5.6 Sol Pro |
| ALE-Bench | 1367.2 | Not measured | Only Gemini 3 Flash Preview measured |
| SciCode | 12.7% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 25 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | 26.3 | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index15 boards, none shared
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1110 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building full-stack apps | 1063 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building mobile apps | 1090 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building Android apps | 1050 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building Godot games | 1161 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: PowerPoint slides | 1036 | Not measured | Only Gemini 3 Flash Preview measured |
| Finance Agent (Vals AI) | 42.5% | Not measured | Only Gemini 3 Flash Preview measured |
| Tax Agent Bench (Vals AI) | 11.8% | Not measured | Only Gemini 3 Flash Preview measured |
| Legal Research Bench (Vals AI) | 18.3% | Not measured | Only Gemini 3 Flash Preview measured |
| Excel Modeling Benchmark (Vals AI) | 26.0% | Not measured | Only Gemini 3 Flash Preview measured |
| τ²-Bench Telecom | 80.4% | Not measured | Only Gemini 3 Flash Preview measured |
| APEX-Agents | Not measured | 51.4% | Only GPT-5.6 Sol Pro measured |
| BALROG | 48.1% | Not measured | Only Gemini 3 Flash Preview measured |
| DeepResearch Bench | 49.8% | Not measured | Only Gemini 3 Flash Preview measured |
| Vending-Bench 2 | $3,635 | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 26 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| GPQA Diamond | 87.9% | Not measured | Only Gemini 3 Flash Preview measured |
| MMMU Pro (Vals AI) | 87.6% | Not measured | Only Gemini 3 Flash Preview measured |
| GPQA Diamond (Artificial Analysis run) | 89.8% | Not measured | Only Gemini 3 Flash Preview measured |
| Humanity's Last Exam (Artificial Analysis run) | 36.6% | Not measured | Only Gemini 3 Flash Preview measured |
| GPQA Diamond (Epoch AI run) | 89.4% | Not measured | Only Gemini 3 Flash Preview measured |
| ARC-AGI | 84.7% | Not measured | Only Gemini 3 Flash Preview measured |
| ARC-AGI-2 | 33.6% | Not measured | Only Gemini 3 Flash Preview measured |
| SimpleBench | 61.1% | 71.7% | GPT-5.6 Sol Pro |
| Chess puzzles | 39.0% | 68.0% | GPT-5.6 Sol Pro |
| Mystery game puzzles | 26.0% | Not measured | Only Gemini 3 Flash Preview measured |
| VPCT | 72.6% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 11 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| AIME | 95.6% | Not measured | Only Gemini 3 Flash Preview measured |
| MGSM (Vals AI) | 93.3% | Not measured | Only Gemini 3 Flash Preview measured |
| AA Math Index | 97.0 | Not measured | Only Gemini 3 Flash Preview measured |
| AIME 2025 (Artificial Analysis run) | 97.0% | Not measured | Only Gemini 3 Flash Preview measured |
| OTIS Mock AIME | 95.6% | Not measured | Only Gemini 3 Flash Preview measured |
| FrontierMath, tiers 1 to 3 | 51.2% | Not measured | Only Gemini 3 Flash Preview measured |
| FrontierMath, tier 4 | 17.1% | 80.5% | GPT-5.6 Sol Pro |
| ProofBench | 15.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 5 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index12 boards, none shared
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| MMLU Pro | 88.6% | Not measured | Only Gemini 3 Flash Preview measured |
| LegalBench (Vals AI) | 86.9% | Not measured | Only Gemini 3 Flash Preview measured |
| CaseLaw (Vals AI) | 55.8% | Not measured | Only Gemini 3 Flash Preview measured |
| CorpFin (Vals AI) | 66.4% | Not measured | Only Gemini 3 Flash Preview measured |
| TaxEval (Vals AI) | 73.9% | Not measured | Only Gemini 3 Flash Preview measured |
| MortgageTax (Vals AI) | 68.7% | Not measured | Only Gemini 3 Flash Preview measured |
| MedQA (Vals AI) | 95.8% | Not measured | Only Gemini 3 Flash Preview measured |
| MedCode (Vals AI) | 55.9% | Not measured | Only Gemini 3 Flash Preview measured |
| MMLU Pro (Artificial Analysis run) | 89.0% | Not measured | Only Gemini 3 Flash Preview measured |
| SimpleQA Verified | 66.8% | Not measured | Only Gemini 3 Flash Preview measured |
| GeoBench | 88.0% | Not measured | Only Gemini 3 Flash Preview measured |
| FACTS Benchmark Suite | 63.4% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 6 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index4 boards, none shared
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| Design Arena: websites | 1196 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: game dev | 1166 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: 3D | 1184 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: all code categories | 1189 | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 5 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 51.8% | Not measured | Only Gemini 3 Flash Preview measured |
| MedScribe (Vals AI) | 69.9% | Not measured | Only Gemini 3 Flash Preview measured |
| Vals Multimodal Index | 52.2% | Not measured | Only Gemini 3 Flash Preview measured |
| IFBench | 78.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Long context reasoning (AA-LCR) | 78.0% | Not measured | Only Gemini 3 Flash Preview measured |
| DTBench | 89.1% | 96.0% | GPT-5.6 Sol Pro |
| LMCA | 43.1% | 59.2% | GPT-5.6 Sol Pro |
| Neither model has a result on the other 39 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3 Flash Preview | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Gemini 3 Flash Preview costs less
Repository review
50K input + 3K output tokens
Gemini 3 Flash Preview costs less
Agent loop
200K input + 10K output tokens
Gemini 3 Flash Preview costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Google Gemini 3 Flash Preview | OpenAI GPT-5.6 Sol Pro |
|---|---|---|
| Maker | OpenAI | |
| Weights | No public weights listed | No public weights listed |
| Released | December 17, 2025 | July 9, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.50 | $4.00 |
| Output $/Mtok | $3.00 | $20.00 |
| Coding index | 43.7 | Not benchmarked |
| Independent measurements behind it | 2 | 0 |
| Cost per solved task | $0.37 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3 Flash Preview better than GPT-5.6 Sol Pro for coding?
Only Gemini 3 Flash Preview has a coding score, 43.7 on the Vibe Coding Index; GPT-5.6 Sol Pro has none, so the two cannot be ranked on coding. Pick GPT-5.6 Sol Pro for a larger context window (1.05M against 1.05M tokens) and work measured by WeirdML or SimpleBench, where it leads.
Which is cheaper, Gemini 3 Flash Preview or GPT-5.6 Sol Pro?
Gemini 3 Flash Preview costs $0.50 per million input tokens and $3.00 per million output tokens; GPT-5.6 Sol Pro costs $4.00 and $20.00. Cost per solved task is known for Gemini 3 Flash Preview only.
Which has the bigger context window, Gemini 3 Flash Preview or GPT-5.6 Sol Pro?
GPT-5.6 Sol Pro, with 1.05M tokens against 1.05M.
How many benchmarks is the Gemini 3 Flash Preview vs GPT-5.6 Sol Pro comparison based on?
6 benchmarks have a result for both models as of October 21, 2026. Gemini 3 Flash Preview's coding index rests on 2 independent benchmarks and GPT-5.6 Sol Pro's on 0. Where only one model has a result, the page says so instead of naming a winner.