Gemini 3 Flash Preview vs Grok 4.5
Grok 4.5 leads Gemini 3 Flash Preview on coding, 58.6 to 43.7 on the Vibe Coding Index, and Gemini 3 Flash Preview costs 2.0x less per output token ($3.00 vs $6.00 per million). Updated October 22, 2026; 52 benchmarks have a result for both.
Gemini 3 Flash Preview or Grok 4.5: which to pick
Pick Grok 4.5 for coding: it scores 58.6 on the Vibe Coding Index against 43.7 for Gemini 3 Flash Preview.
Pick Gemini 3 Flash Preview for output tokens 2.0x cheaper ($3.00 vs $6.00 per million) and a lower cost per solved task ($0.37 against $0.62).
- Shared results
- 52
- Gemini 3 Flash Preview only
- 19
- Grok 4.5 only
- 71
- Like-for-like categories
- 8 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
Grok 4.5
Grok 4.5 scores 58.6 against 43.7.
2 and 6 benchmarks behind the scores
Intelligence
AA Intelligence Index
Grok 4.5
Grok 4.5 leads, 38.8 against 26.3.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Grok 4.5 has a AA Agentic Index result, 41.2.
Directional only
Reasoning
GPQA Diamond
Grok 4.5
Grok 4.5 leads, 92.9% against 87.9%.
Same board, both measured
Math
AIME
No call
Only Gemini 3 Flash Preview has a AIME result, 95.6%.
Directional only
Knowledge
MMLU Pro
Grok 4.5
Grok 4.5 leads, 89.2% against 88.6%.
Same board, both measured
Web design
Design Arena: websites
Grok 4.5
Grok 4.5 leads, 1281 against 1196.
Same board, both measured
Long documents
Listed context window
Gemini 3 Flash Preview
Gemini 3 Flash Preview takes 1.05M tokens against 500K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 3 Flash Preview
Gemini 3 Flash Preview $0.0020, Grok 4.5 $0.0050 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Gemini 3 Flash Preview
Gemini 3 Flash Preview $0.37, Grok 4.5 $0.62.
Published attempt cost and pass rate
At a glance
- Coding index
- Gemini 3 Flash Preview 43.7 from 2 benchmarks, Grok 4.5 58.6 from 6 benchmarks.
- Widest category
- Agentic work, 16.0 points apart on average over 11 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Gemini 3 Flash Preview 20.2% against Grok 4.5 69.0%, 48.8 points apart on a 0 to 100 scale.
- Output price
- Gemini 3 Flash Preview $3.00 against Grok 4.5 $6.00 per million output tokens, 2.0x apart.
- Context window
- Gemini 3 Flash Preview takes 1.05M tokens, Grok 4.5 500K.
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 | Grok 4.5 | Ties |
|---|---|---|---|---|
| Coding | 3 | 5 | 1 tie | |
| Intelligence | 0 | 1 | ||
| Agentic work | 0 | 11 | ||
| Reasoning | 2 | 7 | ||
| Math | 0 | 4 | ||
| Knowledge | 6 | 2 | ||
| Web design | 0 | 4 | ||
| General | 1 | 5 | ||
| All shared boards | 12 | 39 | 1 tie |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index35
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | Leader |
|---|---|---|---|
| SWE-bench Verified | 75.8% | Not measured | Only Gemini 3 Flash Preview measured |
| LiveBench coding | Not measured | 94.3% | Only Grok 4.5 measured |
| LMArena WebDev | Not measured | 1553 | Only Grok 4.5 measured |
| AA Coding Index | Not measured | 72.4 | Only Grok 4.5 measured |
| LiveCodeBench (Vals AI) | 85.6% | 87.3% | Grok 4.5 |
| SWE-bench Verified (Vals AI) | 75.0% | 86.6% | Grok 4.5 |
| Terminal-Bench 4 (Vals AI) | Not measured | 8.6% | Only Grok 4.5 measured |
| Vibe Code Bench (Vals AI) | 20.2% | 69.0% | Grok 4.5 |
| Code migration (Vals AI) | 6.4% | 36.6% | Grok 4.5 |
| ProgramBench (Vals AI) | 0.0% | 0.0% | Tie |
| IOI (Vals AI) | Not measured | 40.6% | Only Grok 4.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 53.9% | 67.8% | Grok 4.5 |
| SkillsBench (Vals AI) | Not measured | 66.0% | Only Grok 4.5 measured |
| CyberBench (Vals AI) | Not measured | 71.0% | Only Grok 4.5 measured |
| LiveCodeBench (Artificial Analysis run) | 90.8% | Not measured | Only Gemini 3 Flash Preview measured |
| SciCode | Not measured | 55.0% | Only Grok 4.5 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 |
| FrontierCode | Not measured | 42.4% | Only Grok 4.5 measured |
| GSO-Bench | 9.8% | Not measured | Only Gemini 3 Flash Preview measured |
| WeirdML | 61.6% | 46.4% | Gemini 3 Flash Preview |
| ALE-Bench | 1367.2 | 1309.3 | Gemini 3 Flash Preview |
| LMArena Text: coding | Not measured | 1474 | Only Grok 4.5 measured |
| LMArena Text: software and IT | Not measured | 1471 | Only Grok 4.5 measured |
| LMArena WebDev: React | Not measured | 1556 | Only Grok 4.5 measured |
| LMArena WebDev: HTML | Not measured | 1567 | Only Grok 4.5 measured |
| LMArena WebDev: from an image | Not measured | 1562 | Only Grok 4.5 measured |
| SciCode | 12.7% | 6.5% | Gemini 3 Flash Preview |
| Neither model has a result on the other 11 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | Leader |
|---|---|---|---|
| AA Intelligence Index | 26.3 | 38.8 | Grok 4.5 |
| Epoch Capabilities Index | Not measured | 154.1 | Only Grok 4.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index011
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 41.2 | Only Grok 4.5 measured |
| Design Arena: agents building web apps | 1111 | 1218 | Grok 4.5 |
| Design Arena: agents building full-stack apps | 1063 | 1249 | Grok 4.5 |
| Design Arena: agents building mobile apps | 1090 | 1220 | Grok 4.5 |
| Design Arena: agents building Android apps | 1051 | 1236 | Grok 4.5 |
| Design Arena: agents building Godot games | 1161 | 1229 | Grok 4.5 |
| Design Arena: agents building games | Not measured | 1236 | Only Grok 4.5 measured |
| Design Arena: HTML slides | Not measured | 1205 | Only Grok 4.5 measured |
| Design Arena: PowerPoint slides | 1036 | 1230 | Grok 4.5 |
| LiveBench research | Not measured | 85.9% | Only Grok 4.5 measured |
| LiveBench browser | Not measured | 44.0% | Only Grok 4.5 measured |
| LiveBench long agentic | Not measured | 27.9% | Only Grok 4.5 measured |
| SREBench (Vals AI) | Not measured | 0.8% | Only Grok 4.5 measured |
| Finance Agent (Vals AI) | 42.5% | 48.4% | Grok 4.5 |
| Tax Agent Bench (Vals AI) | 11.8% | 24.9% | Grok 4.5 |
| Legal Research Bench (Vals AI) | 18.3% | 38.0% | Grok 4.5 |
| Excel Modeling Benchmark (Vals AI) | 26.0% | 52.9% | Grok 4.5 |
| Time Horizon Index (Vals AI) | Not measured | 6.3% | Only Grok 4.5 measured |
| τ²-Bench Telecom | 80.4% | Not measured | Only Gemini 3 Flash Preview measured |
| APEX-Agents | Not measured | 56.2% | Only Grok 4.5 measured |
| BALROG | 48.1% | Not measured | Only Gemini 3 Flash Preview measured |
| DeepResearch Bench | 49.8% | Not measured | Only Gemini 3 Flash Preview measured |
| PostTrainBench | Not measured | 23.4% | Only Grok 4.5 measured |
| Vending-Bench 2 | $3,635 | $3,887 | Grok 4.5 |
| LMArena Search | Not measured | 1216 | Only Grok 4.5 measured |
| Neither model has a result on the other 16 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index27
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | Leader |
|---|---|---|---|
| GPQA Diamond | 87.9% | 92.9% | Grok 4.5 |
| LiveBench reasoning | Not measured | 87.2% | Only Grok 4.5 measured |
| MMMU Pro (Vals AI) | 87.6% | 61.8% | Gemini 3 Flash Preview |
| GPQA Diamond (Artificial Analysis run) | 89.8% | 93.1% | Grok 4.5 |
| Humanity's Last Exam (Artificial Analysis run) | 36.6% | 42.7% | Grok 4.5 |
| GPQA Diamond (Epoch AI run) | 89.4% | 93.4% | Grok 4.5 |
| ARC-AGI | 84.7% | 87.2% | Grok 4.5 |
| ARC-AGI-2 | 33.6% | 52.6% | Grok 4.5 |
| SimpleBench | 61.1% | 70.0% | Grok 4.5 |
| Chess puzzles | 39.0% | 35.0% | Gemini 3 Flash Preview |
| Mystery game puzzles | 26.0% | Not measured | Only Gemini 3 Flash Preview measured |
| VPCT | 72.6% | Not measured | Only Gemini 3 Flash Preview measured |
| LMArena Text: hard prompts | Not measured | 1462 | Only Grok 4.5 measured |
| LMArena Text: expert | Not measured | 1465 | Only Grok 4.5 measured |
| LMArena Text: hard prompts in English | Not measured | 1464 | Only Grok 4.5 measured |
| LMArena Vision: diagrams | Not measured | 1304 | Only Grok 4.5 measured |
| LMArena Vision: homework | Not measured | 1295 | Only Grok 4.5 measured |
| Kagi LLM Benchmark | Not measured | 83.5% | Only Grok 4.5 measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | 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% | 97.8% | Grok 4.5 |
| FrontierMath, tiers 1 to 3 | 51.2% | 57.2% | Grok 4.5 |
| FrontierMath, tier 4 | 17.1% | 24.4% | Grok 4.5 |
| ProofBench | 15.0% | 31.0% | Grok 4.5 |
| LMArena Text: math | Not measured | 1460 | Only Grok 4.5 measured |
| LMArena Text: mathematical work | Not measured | 1482 | Only Grok 4.5 measured |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index62
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | Leader |
|---|---|---|---|
| MMLU Pro | 88.6% | 89.2% | Grok 4.5 |
| LegalBench (Vals AI) | 86.9% | 86.0% | Gemini 3 Flash Preview |
| CaseLaw (Vals AI) | 55.8% | Not measured | Only Gemini 3 Flash Preview measured |
| CorpFin (Vals AI) | 66.4% | 67.4% | Grok 4.5 |
| TaxEval (Vals AI) | 73.9% | 71.7% | Gemini 3 Flash Preview |
| MortgageTax (Vals AI) | 68.7% | 61.8% | Gemini 3 Flash Preview |
| MedQA (Vals AI) | 95.8% | Not measured | Only Gemini 3 Flash Preview measured |
| MedCode (Vals AI) | 55.9% | 43.3% | Gemini 3 Flash Preview |
| MMLU Pro (Artificial Analysis run) | 89.0% | Not measured | Only Gemini 3 Flash Preview measured |
| SimpleQA Verified | 66.8% | 48.3% | Gemini 3 Flash Preview |
| GeoBench | 88.0% | Not measured | Only Gemini 3 Flash Preview measured |
| LMArena Text: science | Not measured | 1464 | Only Grok 4.5 measured |
| LMArena Text: medicine and healthcare | Not measured | 1440 | Only Grok 4.5 measured |
| LMArena Text: legal and government | Not measured | 1463 | Only Grok 4.5 measured |
| LMArena Text: business and finance | Not measured | 1441 | Only Grok 4.5 measured |
| FACTS Benchmark Suite | 63.4% | 50.2% | Gemini 3 Flash Preview |
| Neither model has a result on the other 2 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | Leader |
|---|---|---|---|
| Design Arena: websites | 1196 | 1281 | Grok 4.5 |
| Design Arena: UI components | Not measured | 1280 | Only Grok 4.5 measured |
| Design Arena: game dev | 1166 | 1264 | Grok 4.5 |
| Design Arena: data viz | Not measured | 1266 | Only Grok 4.5 measured |
| Design Arena: 3D | 1183 | 1257 | Grok 4.5 |
| Design Arena: all code categories | 1189 | 1275 | Grok 4.5 |
| Design Arena: SVG | Not measured | 1215 | Only Grok 4.5 measured |
| Design Arena: ASCII art | Not measured | 1256 | Only Grok 4.5 measured |
| LiveBench design | Not measured | 78.1% | Only Grok 4.5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index15
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 73.0% | Only Grok 4.5 measured |
| SAGE (Vals AI) | 51.8% | 35.0% | Gemini 3 Flash Preview |
| MedScribe (Vals AI) | 69.9% | 86.9% | Grok 4.5 |
| Vals Multimodal Index | 52.2% | 63.4% | Grok 4.5 |
| IFBench | 78.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Long context reasoning (AA-LCR) | 78.0% | 79.3% | Grok 4.5 |
| DTBench | 89.1% | 96.5% | Grok 4.5 |
| LMCA | 43.1% | 45.2% | Grok 4.5 |
| Surface Evolver Bench | Not measured | 74.4% | Only Grok 4.5 measured |
| Furniture assembly | Not measured | 22.5% | Only Grok 4.5 measured |
| LMArena Text | Not measured | 1448 | Only Grok 4.5 measured |
| LMArena Text: instruction following | Not measured | 1445 | Only Grok 4.5 measured |
| LMArena Text: creative writing | Not measured | 1442 | Only Grok 4.5 measured |
| LMArena Vision | Not measured | 1287 | Only Grok 4.5 measured |
| LMArena Text: English | Not measured | 1453 | Only Grok 4.5 measured |
| LMArena Text: non-English | Not measured | 1440 | Only Grok 4.5 measured |
| LMArena Text: Chinese | Not measured | 1495 | Only Grok 4.5 measured |
| LMArena Text: German | Not measured | 1448 | Only Grok 4.5 measured |
| LMArena Text: Japanese | Not measured | 1430 | Only Grok 4.5 measured |
| LMArena Text: Korean | Not measured | 1406 | Only Grok 4.5 measured |
| LMArena Text: French | Not measured | 1457 | Only Grok 4.5 measured |
| LMArena Text: Spanish | Not measured | 1451 | Only Grok 4.5 measured |
| LMArena Text: Russian | Not measured | 1449 | Only Grok 4.5 measured |
| LMArena Text: Polish | Not measured | 1432 | Only Grok 4.5 measured |
| LMArena Text: multi-turn | Not measured | 1456 | Only Grok 4.5 measured |
| LMArena Text: longer queries | Not measured | 1462 | Only Grok 4.5 measured |
| LMArena Text: writing and language | Not measured | 1445 | Only Grok 4.5 measured |
| LMArena Text: entertainment and media | Not measured | 1434 | Only Grok 4.5 measured |
| LMArena Vision: English | Not measured | 1285 | Only Grok 4.5 measured |
| LMArena Vision: Chinese | Not measured | 1345 | Only Grok 4.5 measured |
| LMArena Vision: reading text | Not measured | 1293 | Only Grok 4.5 measured |
| LMArena Vision: humor | Not measured | 1276 | Only Grok 4.5 measured |
| LMArena Vision: creative writing | Not measured | 1293 | Only Grok 4.5 measured |
| LMArena Document | Not measured | 1452 | Only Grok 4.5 measured |
| Neither model has a result on the other 12 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3 Flash Preview | Grok 4.5 | 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 | SpaceXAI Grok 4.5 |
|---|---|---|
| Maker | xAI | |
| Weights | No public weights listed | No public weights listed |
| Released | December 17, 2025 | July 8, 2026 |
| Context window | 1.05M | 500K |
| Input $/Mtok | $0.50 | $2.00 |
| Output $/Mtok | $3.00 | $6.00 |
| Coding index | 43.7 | 58.6 |
| Independent measurements behind it | 2 | 6 |
| Cost per solved task | $0.37 | $0.62 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3 Flash Preview better than Grok 4.5 for coding?
Pick Grok 4.5 for coding: it scores 58.6 on the Vibe Coding Index against 43.7 for Gemini 3 Flash Preview. Pick Gemini 3 Flash Preview for output tokens 2.0x cheaper ($3.00 vs $6.00 per million) and a lower cost per solved task ($0.37 against $0.62).
Which is cheaper, Gemini 3 Flash Preview or Grok 4.5?
Gemini 3 Flash Preview costs $0.50 per million input tokens and $3.00 per million output tokens; Grok 4.5 costs $2.00 and $6.00. Per solved SWE-bench Verified task, Gemini 3 Flash Preview costs $0.37 and Grok 4.5 $0.62.
Which has the bigger context window, Gemini 3 Flash Preview or Grok 4.5?
Gemini 3 Flash Preview, with 1.05M tokens against 500K.
How many benchmarks is the Gemini 3 Flash Preview vs Grok 4.5 comparison based on?
52 benchmarks have a result for both models as of October 22, 2026. Gemini 3 Flash Preview's coding index rests on 2 independent benchmarks and Grok 4.5's on 6. Where only one model has a result, the page says so instead of naming a winner.