Gemini 3.5 Flash vs o3 Mini
Gemini 3.5 Flash leads o3 Mini on the Artificial Analysis Intelligence Index, 33.6 to 12.5, and o3 Mini costs 2.0x less per output token ($4.40 vs $9.00 per million). Updated October 21, 2026; 57 benchmarks have a result for both.
Gemini 3.5 Flash or o3 Mini: which to pick
Only Gemini 3.5 Flash has a coding score, 39.8 on the Vibe Coding Index; o3 Mini has none, so the two cannot be ranked on coding.
Pick o3 Mini for output tokens 2.0x cheaper ($4.40 vs $9.00 per million).
- Shared results
- 57
- Gemini 3.5 Flash only
- 55
- o3 Mini only
- 14
- Like-for-like categories
- 7 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 3.5 Flash has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Gemini 3.5 Flash
Gemini 3.5 Flash leads, 33.6 against 12.5.
Same board, both measured
Reasoning
GPQA Diamond
Gemini 3.5 Flash
Gemini 3.5 Flash leads, 92.7% against 75.5%.
Same board, both measured
Math
AIME
No call
Only o3 Mini has a AIME result, 86.5%.
Directional only
Knowledge
MMLU Pro
Gemini 3.5 Flash
Gemini 3.5 Flash leads, 89.5% against 78.7%.
Same board, both measured
Web design
Design Arena: websites
No call
Only Gemini 3.5 Flash has a Design Arena: websites result, 1268.
Directional only
Long documents
Listed context window
Gemini 3.5 Flash
Gemini 3.5 Flash takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
o3 Mini
Gemini 3.5 Flash $0.0060, o3 Mini $0.0033 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3.5 Flash has the number, $1.21.
Directional only
At a glance
- Coding index
- Gemini 3.5 Flash 39.8 from 4 benchmarks, o3 Mini not benchmarked.
- Widest category
- Agentic work, 64.3 points apart on average over 1 shared benchmark.
- Widest single gap
- ARC-AGI-2: Gemini 3.5 Flash 72.1% against o3 Mini 3.0%, 69.1 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.5 Flash $9.00 against o3 Mini $4.40 per million output tokens, 2.0x apart.
- Context window
- Gemini 3.5 Flash takes 1.05M tokens, o3 Mini 200K.
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 3.5 Flash | Bars | o3 Mini | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 12 | 0 | ||
| Math | 5 | 0 | ||
| Knowledge | 9 | 0 | ||
| General | 21 | 0 | ||
| All shared boards | 57 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 60.4% | Only o3 Mini measured |
| SWE-bench Verified | Not measured | 42.4% | Only o3 Mini measured |
| SWE-bench Lite | Not measured | 32.3% | Only o3 Mini measured |
| LMArena WebDev | 1499 | Not measured | Only Gemini 3.5 Flash measured |
| LiveCodeBench (Vals AI) | 87.6% | 71.5% | Gemini 3.5 Flash |
| SWE-bench Verified (Vals AI) | 78.8% | Not measured | Only Gemini 3.5 Flash measured |
| Terminal-Bench 4 (Vals AI) | 6.1% | Not measured | Only Gemini 3.5 Flash measured |
| Vibe Code Bench (Vals AI) | 48.7% | Not measured | Only Gemini 3.5 Flash measured |
| Code migration (Vals AI) | 26.8% | Not measured | Only Gemini 3.5 Flash measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Gemini 3.5 Flash measured |
| Terminal-Bench 2.1 (Vals AI) | 74.2% | Not measured | Only Gemini 3.5 Flash measured |
| SkillsBench (Vals AI) | 52.7% | Not measured | Only Gemini 3.5 Flash measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 73.4% | Only o3 Mini measured |
| SciCode | 53.9% | 42.8% | Gemini 3.5 Flash |
| Terminal-Bench Hard (Artificial Analysis run) | 46.2% | 6.8% | Gemini 3.5 Flash |
| GSO-Bench | Not measured | 1.3% | Only o3 Mini measured |
| WeirdML | 62.6% | 43.7% | Gemini 3.5 Flash |
| Cybench | Not measured | 22.5% | Only o3 Mini measured |
| ALE-Bench | 911.0 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Text: coding | 1493 | 1378 | Gemini 3.5 Flash |
| LMArena Text: software and IT | 1494 | 1364 | Gemini 3.5 Flash |
| LMArena WebDev: React | 1495 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena WebDev: HTML | 1522 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena WebDev: from an image | 1504 | Not measured | Only Gemini 3.5 Flash measured |
| SciCode | 12.3% | 7.7% | Gemini 3.5 Flash |
| Neither model has a result on the other 14 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| AA Intelligence Index | 33.6 | 12.5 | Gemini 3.5 Flash |
| Epoch Capabilities Index | 154.9 | 140.2 | Gemini 3.5 Flash |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1202 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: agents building full-stack apps | 1197 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: agents building mobile apps | 1174 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: agents building Android apps | 1184 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: agents building Godot games | 1098 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: agents building games | 1180 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: HTML slides | 1142 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: PowerPoint slides | 1179 | Not measured | Only Gemini 3.5 Flash measured |
| Finance Agent (Vals AI) | 57.9% | Not measured | Only Gemini 3.5 Flash measured |
| Tax Agent Bench (Vals AI) | 21.6% | Not measured | Only Gemini 3.5 Flash measured |
| Legal Research Bench (Vals AI) | 30.8% | Not measured | Only Gemini 3.5 Flash measured |
| Excel Modeling Benchmark (Vals AI) | 63.5% | Not measured | Only Gemini 3.5 Flash measured |
| Terminal-Bench-Science (Vals AI) | 5.7% | Not measured | Only Gemini 3.5 Flash measured |
| τ²-Bench Telecom | 95.6% | 31.3% | Gemini 3.5 Flash |
| APEX-Agents | 27.5% | Not measured | Only Gemini 3.5 Flash measured |
| Vending-Bench 2 | $5,396 | Not measured | Only Gemini 3.5 Flash measured |
| Neither model has a result on the other 25 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index120
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| GPQA Diamond | 92.7% | 75.5% | Gemini 3.5 Flash |
| MMMU Pro (Vals AI) | 88.3% | Not measured | Only Gemini 3.5 Flash measured |
| GPQA Diamond (Artificial Analysis run) | 92.2% | 77.3% | Gemini 3.5 Flash |
| Humanity's Last Exam (Artificial Analysis run) | 42.7% | 12.0% | Gemini 3.5 Flash |
| GPQA Diamond (Epoch AI run) | 92.8% | 77.0% | Gemini 3.5 Flash |
| ARC-AGI | 92.5% | 34.5% | Gemini 3.5 Flash |
| ARC-AGI-2 | 72.1% | 3.0% | Gemini 3.5 Flash |
| SimpleBench | 76.7% | 22.8% | Gemini 3.5 Flash |
| Chess puzzles | 45.0% | 15.0% | Gemini 3.5 Flash |
| Mystery game puzzles | 32.0% | 7.0% | Gemini 3.5 Flash |
| EBR-bench | 4.8% | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Text: hard prompts | 1488 | 1365 | Gemini 3.5 Flash |
| LMArena Text: expert | 1495 | 1364 | Gemini 3.5 Flash |
| LMArena Text: hard prompts in English | 1483 | 1375 | Gemini 3.5 Flash |
| LMArena Vision: diagrams | 1323 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Vision: homework | 1330 | Not measured | Only Gemini 3.5 Flash measured |
| Neither model has a result on the other 6 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| AIME | Not measured | 86.5% | Only o3 Mini measured |
| MATH 500 (Vals AI) | Not measured | 91.8% | Only o3 Mini measured |
| MGSM (Vals AI) | Not measured | 91.3% | Only o3 Mini measured |
| OTIS Mock AIME | 95.6% | 76.9% | Gemini 3.5 Flash |
| FrontierMath, tiers 1 to 3 | 62.8% | 18.6% | Gemini 3.5 Flash |
| FrontierMath, tier 4 | 26.8% | 0.0% | Gemini 3.5 Flash |
| ProofBench | 31.0% | Not measured | Only Gemini 3.5 Flash measured |
| MATH level 5 | Not measured | 96.5% | Only o3 Mini measured |
| LMArena Text: math | 1504 | 1396 | Gemini 3.5 Flash |
| LMArena Text: mathematical work | 1495 | 1399 | Gemini 3.5 Flash |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index90
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| MMLU Pro | 89.5% | 78.7% | Gemini 3.5 Flash |
| LegalBench (Vals AI) | 83.6% | 71.5% | Gemini 3.5 Flash |
| CorpFin (Vals AI) | 64.7% | 45.3% | Gemini 3.5 Flash |
| TaxEval (Vals AI) | 74.4% | 69.4% | Gemini 3.5 Flash |
| MortgageTax (Vals AI) | 68.1% | Not measured | Only Gemini 3.5 Flash measured |
| MedQA (Vals AI) | Not measured | 94.8% | Only o3 Mini measured |
| MedCode (Vals AI) | 55.8% | Not measured | Only Gemini 3.5 Flash measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 80.2% | Only o3 Mini measured |
| SimpleQA Verified | 66.2% | 15.3% | Gemini 3.5 Flash |
| LMArena Text: science | 1495 | 1339 | Gemini 3.5 Flash |
| LMArena Text: medicine and healthcare | 1483 | 1330 | Gemini 3.5 Flash |
| LMArena Text: legal and government | 1488 | 1328 | Gemini 3.5 Flash |
| LMArena Text: business and finance | 1467 | 1313 | Gemini 3.5 Flash |
| FACTS Benchmark Suite | 63.1% | Not measured | Only Gemini 3.5 Flash measured |
| Neither model has a result on the other 4 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| Design Arena: websites | 1268 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: UI components | 1273 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: game dev | 1263 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: data viz | 1236 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: 3D | 1244 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: all code categories | 1266 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: SVG | 1254 | Not measured | Only Gemini 3.5 Flash measured |
| Design Arena: ASCII art | 1254 | Not measured | Only Gemini 3.5 Flash measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index210
| Benchmark | Gemini 3.5 Flash | o3 Mini | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | 59.5% | Not measured | Only Gemini 3.5 Flash measured |
| SAGE (Vals AI) | 49.9% | Not measured | Only Gemini 3.5 Flash measured |
| MedScribe (Vals AI) | 76.6% | Not measured | Only Gemini 3.5 Flash measured |
| Vals Multimodal Index | 62.9% | Not measured | Only Gemini 3.5 Flash measured |
| IFBench | 76.3% | 67.1% | Gemini 3.5 Flash |
| Long context reasoning (AA-LCR) | 74.3% | 43.0% | Gemini 3.5 Flash |
| DTBench | 94.7% | 68.8% | Gemini 3.5 Flash |
| LMCA | 47.1% | 19.0% | Gemini 3.5 Flash |
| Fiction.LiveBench | Not measured | 50.0% | Only o3 Mini measured |
| Creative writing (Lech Mazur) | Not measured | 61.7% | Only o3 Mini measured |
| Surface Evolver Bench | 58.1% | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Text | 1482 | 1337 | Gemini 3.5 Flash |
| LMArena Text: instruction following | 1467 | 1337 | Gemini 3.5 Flash |
| LMArena Text: creative writing | 1470 | 1286 | Gemini 3.5 Flash |
| LMArena Vision | 1308 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Text: English | 1481 | 1351 | Gemini 3.5 Flash |
| LMArena Text: non-English | 1475 | 1319 | Gemini 3.5 Flash |
| LMArena Text: Chinese | 1527 | 1379 | Gemini 3.5 Flash |
| LMArena Text: German | 1494 | 1303 | Gemini 3.5 Flash |
| LMArena Text: Japanese | 1486 | 1286 | Gemini 3.5 Flash |
| LMArena Text: Korean | 1448 | 1313 | Gemini 3.5 Flash |
| LMArena Text: French | 1490 | 1334 | Gemini 3.5 Flash |
| LMArena Text: Spanish | 1480 | 1321 | Gemini 3.5 Flash |
| LMArena Text: Russian | 1493 | 1304 | Gemini 3.5 Flash |
| LMArena Text: Polish | 1516 | 1294 | Gemini 3.5 Flash |
| LMArena Text: multi-turn | 1481 | 1320 | Gemini 3.5 Flash |
| LMArena Text: longer queries | 1483 | 1343 | Gemini 3.5 Flash |
| LMArena Text: writing and language | 1478 | 1313 | Gemini 3.5 Flash |
| LMArena Text: entertainment and media | 1459 | 1283 | Gemini 3.5 Flash |
| LMArena Vision: English | 1305 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Vision: Chinese | 1377 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Vision: reading text | 1317 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Vision: humor | 1321 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Vision: creative writing | 1301 | Not measured | Only Gemini 3.5 Flash measured |
| LMArena Document | 1463 | Not measured | Only Gemini 3.5 Flash measured |
| Neither model has a result on the other 11 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3.5 Flash | o3 Mini | 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
o3 Mini costs less
Repository review
50K input + 3K output tokens
o3 Mini costs less
Agent loop
200K input + 10K output tokens
o3 Mini 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 3.5 Flash | OpenAI o3 Mini |
|---|---|---|
| Maker | OpenAI | |
| Weights | No public weights listed | No public weights listed |
| Released | May 19, 2026 | January 31, 2025 |
| Context window | 1.05M | 200K |
| Input $/Mtok | $1.50 | $1.10 |
| Output $/Mtok | $9.00 | $4.40 |
| Coding index | 39.8 | Not benchmarked |
| Independent measurements behind it | 4 | 0 |
| Cost per solved task | $1.21 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.5 Flash better than o3 Mini for coding?
Only Gemini 3.5 Flash has a coding score, 39.8 on the Vibe Coding Index; o3 Mini has none, so the two cannot be ranked on coding. Pick o3 Mini for output tokens 2.0x cheaper ($4.40 vs $9.00 per million).
Which is cheaper, Gemini 3.5 Flash or o3 Mini?
Gemini 3.5 Flash costs $1.50 per million input tokens and $9.00 per million output tokens; o3 Mini costs $1.10 and $4.40. Cost per solved task is known for Gemini 3.5 Flash only.
Which has the bigger context window, Gemini 3.5 Flash or o3 Mini?
Gemini 3.5 Flash, with 1.05M tokens against 200K.
How many benchmarks is the Gemini 3.5 Flash vs o3 Mini comparison based on?
57 benchmarks have a result for both models as of October 21, 2026. Gemini 3.5 Flash's coding index rests on 4 independent benchmarks and o3 Mini's on 0. Where only one model has a result, the page says so instead of naming a winner.