Gemini 3.8 Flash vs Step 3.5 Flash
Updated October 21, 2026. 32 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
vs boards won of 32 shared
Decision reading
Only Gemini 3.8 Flash has a coding score, 61.6 on the Vibe Coding Index; Step 3.5 Flash has none, so the two cannot be ranked on coding.
Step 3.5 Flash has the edge where output tokens cost 12.5x less.
Model AGemini 3.8 FlashGoogle61.6/1006 independent benchmarks$2.74 per solved taskModel BStep 3.5 FlashStepFunNot benchmarkedNo coding benchmarkNo cost per solved task
- Shared results
- 32
- Gemini 3.8 Flash only
- 94
- Step 3.5 Flash only
- 3
- Like-for-like categories
- 6 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
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 3.8 Flash has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 40.9 against 17.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Gemini 3.8 Flash has a AA Agentic Index result, 40.2.
Directional only
Reasoning
GPQA Diamond
No call
Only Gemini 3.8 Flash has a GPQA Diamond result, 94.4%.
Directional only
Knowledge
MMLU Pro
No call
Only Gemini 3.8 Flash has a MMLU Pro result, 90.2%.
Directional only
Web design
Design Arena: websites
No call
Only Gemini 3.8 Flash has a Design Arena: websites result, 1301.
Directional only
General
Vals Index
No call
Only Gemini 3.8 Flash has a Vals Index result, 56.0%.
Directional only
Long documents
Listed context window
Gemini 3.8 Flash
Gemini 3.8 Flash takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 3.5 Flash
Gemini 3.8 Flash $0.0026, Step 3.5 Flash $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3.8 Flash has the number, $2.74.
Directional only
At a glance
- Coding index
- Gemini 3.8 Flash 61.6 from 6 benchmarks, Step 3.5 Flash not benchmarked.
- Widest category
- Intelligence, 23.9 points apart on average over 1 shared benchmark.
- Widest single gap
- LMArena Text: Japanese: Gemini 3.8 Flash 1507 against Step 3.5 Flash 1353, 25.7 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.8 Flash $3.75 against Step 3.5 Flash $0.30 per million output tokens, 12.5x apart.
- Context window
- Gemini 3.8 Flash takes 1.05M tokens, Step 3.5 Flash 262K.
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 3.8 Flash | Bars | Step 3.5 Flash | Ties |
|---|---|---|---|---|
| Coding | 2 | 0 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 5 | 0 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 0 | ||
| General | 18 | 0 | ||
| All shared boards | 32 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index20
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| LiveBench coding | 82.2% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena WebDev | 1585 | Not measured | Only Gemini 3.8 Flash measured |
| AA Coding Index | 76.3 | Not measured | Only Gemini 3.8 Flash measured |
| LiveCodeBench (Vals AI) | 89.5% | Not measured | Only Gemini 3.8 Flash measured |
| SWE-bench Verified (Vals AI) | 80.0% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench 4 (Vals AI) | 19.7% | Not measured | Only Gemini 3.8 Flash measured |
| Vibe Code Bench (Vals AI) | 78.7% | Not measured | Only Gemini 3.8 Flash measured |
| Code migration (Vals AI) | 36.5% | Not measured | Only Gemini 3.8 Flash measured |
| ProgramBench (Vals AI) | 1.0% | Not measured | Only Gemini 3.8 Flash measured |
| IOI (Vals AI) | 56.9% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench 2.1 (Vals AI) | 81.3% | Not measured | Only Gemini 3.8 Flash measured |
| SWE-bench Multimodal (Vals AI) | 40.8% | Not measured | Only Gemini 3.8 Flash measured |
| Vibe Code Bench 1-100 (Vals AI) | 18.8% | Not measured | Only Gemini 3.8 Flash measured |
| SkillsBench (Vals AI) | 58.0% | Not measured | Only Gemini 3.8 Flash measured |
| CyberBench (Vals AI) | 43.8% | Not measured | Only Gemini 3.8 Flash measured |
| SciCode | 56.6% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 32.6% | Only Step 3.5 Flash measured |
| FrontierCode | 41.2% | Not measured | Only Gemini 3.8 Flash measured |
| FrontierSWE | 19.6% | Not measured | Only Gemini 3.8 Flash measured |
| WeirdML | 84.8% | Not measured | Only Gemini 3.8 Flash measured |
| ALE-Bench | 1269.7 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: coding | 1508 | 1436 | Gemini 3.8 Flash |
| LMArena Text: software and IT | 1507 | 1434 | Gemini 3.8 Flash |
| LMArena WebDev: React | 1577 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena WebDev: HTML | 1616 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena WebDev: from an image | 1593 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 12 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 40.9 | 17.0 | Gemini 3.8 Flash |
| Epoch Capabilities Index | 157.4 | Not measured | Only Gemini 3.8 Flash measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index26 boards, none shared
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| AA Agentic Index | 40.2 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building web apps | 1238 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building full-stack apps | 1244 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building mobile apps | 1236 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building Android apps | 1071 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building Godot games | 1273 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: PowerPoint slides | 1178 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: spreadsheets | 1051 | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench research | 79.1% | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench browser | 64.0% | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench long agentic | 30.1% | Not measured | Only Gemini 3.8 Flash measured |
| SREBench (Vals AI) | 11.1% | Not measured | Only Gemini 3.8 Flash measured |
| Finance Agent (Vals AI) | 61.4% | Not measured | Only Gemini 3.8 Flash measured |
| Tax Agent Bench (Vals AI) | 32.1% | Not measured | Only Gemini 3.8 Flash measured |
| Legal Research Bench (Vals AI) | 38.9% | Not measured | Only Gemini 3.8 Flash measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 12.1% | Not measured | Only Gemini 3.8 Flash measured |
| Excel Modeling Benchmark (Vals AI) | 72.2% | Not measured | Only Gemini 3.8 Flash measured |
| BioMysteryBench (Vals AI) | 62.2% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench-Science (Vals AI) | 8.6% | Not measured | Only Gemini 3.8 Flash measured |
| Vals Science Index | 35.8% | Not measured | Only Gemini 3.8 Flash measured |
| Time Horizon Index (Vals AI) | 18.8% | Not measured | Only Gemini 3.8 Flash measured |
| CUA-bench (Vals AI) | 4.2% | Not measured | Only Gemini 3.8 Flash measured |
| τ²-Bench Telecom | Not measured | 94.4% | Only Step 3.5 Flash measured |
| APEX-Agents | 64.3% | Not measured | Only Gemini 3.8 Flash measured |
| Remote Labor Index | 5.8% | Not measured | Only Gemini 3.8 Flash measured |
| Vending-Bench 2 | $5,094 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 13 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 94.4% | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench reasoning | 89.3% | Not measured | Only Gemini 3.8 Flash measured |
| MysteryMechanism (Vals AI) | 36.5% | Not measured | Only Gemini 3.8 Flash measured |
| MMMU Pro (Vals AI) | 89.1% | Not measured | Only Gemini 3.8 Flash measured |
| GPQA Diamond (Artificial Analysis run) | 95.3% | 83.1% | Gemini 3.8 Flash |
| Humanity's Last Exam (Artificial Analysis run) | 47.8% | 24.5% | Gemini 3.8 Flash |
| GPQA Diamond (Epoch AI run) | 95.4% | Not measured | Only Gemini 3.8 Flash measured |
| ARC-AGI | 98.5% | Not measured | Only Gemini 3.8 Flash measured |
| ARC-AGI-2 | 89.2% | Not measured | Only Gemini 3.8 Flash measured |
| Chess puzzles | 58.0% | Not measured | Only Gemini 3.8 Flash measured |
| Mystery game puzzles | 47.0% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: hard prompts | 1509 | 1411 | Gemini 3.8 Flash |
| LMArena Text: expert | 1526 | 1421 | Gemini 3.8 Flash |
| LMArena Text: hard prompts in English | 1504 | 1421 | Gemini 3.8 Flash |
| LMArena Vision: diagrams | 1345 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: homework | 1351 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 5 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| OTIS Mock AIME | 98.9% | Not measured | Only Gemini 3.8 Flash measured |
| FrontierMath, tiers 1 to 3 | 68.4% | Not measured | Only Gemini 3.8 Flash measured |
| FrontierMath, tier 4 | 22.0% | Not measured | Only Gemini 3.8 Flash measured |
| ProofBench | 48.0% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: math | 1532 | 1408 | Gemini 3.8 Flash |
| LMArena Text: mathematical work | 1519 | 1421 | Gemini 3.8 Flash |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| MMLU Pro | 90.2% | Not measured | Only Gemini 3.8 Flash measured |
| LegalBench (Vals AI) | 87.0% | Not measured | Only Gemini 3.8 Flash measured |
| TaxEval (Vals AI) | 74.5% | Not measured | Only Gemini 3.8 Flash measured |
| MortgageTax (Vals AI) | 65.3% | Not measured | Only Gemini 3.8 Flash measured |
| MedCode (Vals AI) | 48.1% | Not measured | Only Gemini 3.8 Flash measured |
| SimpleQA Verified | 69.7% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: science | 1523 | 1415 | Gemini 3.8 Flash |
| LMArena Text: medicine and healthcare | 1508 | 1408 | Gemini 3.8 Flash |
| LMArena Text: legal and government | 1497 | 1408 | Gemini 3.8 Flash |
| LMArena Text: business and finance | 1479 | 1394 | Gemini 3.8 Flash |
| Neither model has a result on the other 7 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1301 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: UI components | 1318 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: game dev | 1305 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: data viz | 1269 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: 3D | 1295 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: all code categories | 1304 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: SVG | 1295 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: ASCII art | 1264 | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench design | 72.7% | Not measured | Only Gemini 3.8 Flash measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index180
| Benchmark | Gemini 3.8 Flash | Step 3.5 Flash | Leader |
|---|---|---|---|
| Vals Index | 56.0% | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench data analysis | 54.0% | Not measured | Only Gemini 3.8 Flash measured |
| Public Benefits Bench (Vals AI) | 65.3% | Not measured | Only Gemini 3.8 Flash measured |
| SAGE (Vals AI) | 35.1% | Not measured | Only Gemini 3.8 Flash measured |
| MedScribe (Vals AI) | 84.5% | Not measured | Only Gemini 3.8 Flash measured |
| IFBench | Not measured | 66.5% | Only Step 3.5 Flash measured |
| Long context reasoning (AA-LCR) | 84.0% | 63.0% | Gemini 3.8 Flash |
| DTBench | 95.7% | Not measured | Only Gemini 3.8 Flash measured |
| LMCA | 52.9% | Not measured | Only Gemini 3.8 Flash measured |
| Surface Evolver Bench | 76.9% | Not measured | Only Gemini 3.8 Flash measured |
| Furniture assembly | 31.7% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text | 1499 | 1403 | Gemini 3.8 Flash |
| LMArena Text: instruction following | 1492 | 1385 | Gemini 3.8 Flash |
| LMArena Text: creative writing | 1488 | 1357 | Gemini 3.8 Flash |
| LMArena Vision | 1315 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: English | 1498 | 1417 | Gemini 3.8 Flash |
| LMArena Text: non-English | 1491 | 1385 | Gemini 3.8 Flash |
| LMArena Text: Chinese | 1553 | 1446 | Gemini 3.8 Flash |
| LMArena Text: German | 1501 | 1405 | Gemini 3.8 Flash |
| LMArena Text: Japanese | 1507 | 1353 | Gemini 3.8 Flash |
| LMArena Text: Korean | 1464 | 1351 | Gemini 3.8 Flash |
| LMArena Text: French | 1496 | 1421 | Gemini 3.8 Flash |
| LMArena Text: Spanish | 1487 | 1419 | Gemini 3.8 Flash |
| LMArena Text: Russian | 1514 | 1385 | Gemini 3.8 Flash |
| LMArena Text: Polish | 1497 | 1389 | Gemini 3.8 Flash |
| LMArena Text: multi-turn | 1503 | 1404 | Gemini 3.8 Flash |
| LMArena Text: longer queries | 1507 | 1402 | Gemini 3.8 Flash |
| LMArena Text: writing and language | 1494 | 1372 | Gemini 3.8 Flash |
| LMArena Text: entertainment and media | 1480 | 1360 | Gemini 3.8 Flash |
| LMArena Vision: English | 1318 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: Chinese | 1416 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: reading text | 1333 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: humor | 1321 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: creative writing | 1299 | Not measured | Only Gemini 3.8 Flash 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 3.8 Flash | Step 3.5 Flash | 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 3.8 Flash$0.0026Fits in one request
Step 3.5 Flash$0.0003Fits in one request
Step 3.5 Flash costs less
Repository review
50K input + 3K output tokens
Gemini 3.8 Flash$0.049Fits in one request
Step 3.5 Flash$0.0059Fits in one request
Step 3.5 Flash costs less
Agent loop
200K input + 10K output tokens
Gemini 3.8 Flash$0.188Fits in one request
Step 3.5 Flash$0.023Fits in one request
Step 3.5 Flash 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 3.8 Flash | StepFun Step 3.5 Flash |
|---|---|---|
| Maker | StepFun | |
| Weights | No public weights listed | Open weights |
| Released | September 2, 2026 | January 29, 2026 |
| Context window | 1.05M | 262K |
| Input $/Mtok | $0.75 | $0.10 |
| Output $/Mtok | $3.75 | $0.30 |
| Coding index | 61.6 | Not benchmarked |
| Independent measurements behind it | 6 | 0 |
| Cost per solved task | $2.74 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.8 Flash better than Step 3.5 Flash for coding?
Only Gemini 3.8 Flash has a coding score, 61.6 on the Vibe Coding Index; Step 3.5 Flash has none, so the two cannot be ranked on coding. Step 3.5 Flash has the edge where output tokens cost 12.5x less.
Which is cheaper, Gemini 3.8 Flash or Step 3.5 Flash?
Gemini 3.8 Flash costs $0.75 per million input tokens and $3.75 per million output tokens; Step 3.5 Flash costs $0.10 and $0.30. Cost per solved task is known for Gemini 3.8 Flash only.
Which has the bigger context window, Gemini 3.8 Flash or Step 3.5 Flash?
Gemini 3.8 Flash, with 1.05M tokens against 262K.
How many benchmarks is the Gemini 3.8 Flash vs Step 3.5 Flash comparison based on?
32 benchmarks have a result for both models as of October 21, 2026. Gemini 3.8 Flash's coding index rests on 6 independent benchmarks and Step 3.5 Flash's on 0. Where only one model has a result, the page says so instead of naming a winner.