Gemini 3.8 Flash vs Gemini 3 Flash Preview
Gemini 3.8 Flash leads Gemini 3 Flash Preview on coding, 61.6 to 43.7 on the Vibe Coding Index, and Gemini 3 Flash Preview costs 1.3x less per output token ($3.00 vs $3.75 per million). Updated October 21, 2026; 50 benchmarks have a result for both.
vs boards won of 50 shared
Gemini 3.8 Flash or Gemini 3 Flash Preview: which to pick
Pick Gemini 3.8 Flash for coding: it scores 61.6 on the Vibe Coding Index against 43.7 for Gemini 3 Flash Preview.
Pick Gemini 3 Flash Preview for output tokens 1.3x cheaper ($3.00 vs $3.75 per million) and a lower cost per solved task ($0.37 against $2.74).
Model AGemini 3.8 FlashGoogle61.6/1006 independent benchmarks$2.74 per solved taskModel BGemini 3 Flash PreviewGoogle43.7/1002 independent benchmarks$0.37 per solved task
- Shared results
- 50
- Gemini 3.8 Flash only
- 78
- Gemini 3 Flash Preview only
- 21
- 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
Gemini 3.8 Flash
Gemini 3.8 Flash scores 61.6 against 43.7.
6 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 40.9 against 26.3.
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
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 94.4% 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
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 90.2% against 88.6%.
Same board, both measured
Web design
Design Arena: websites
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 1300 against 1196.
Same board, both measured
General
Vals Index
No call
Only Gemini 3.8 Flash has a Vals Index result, 56.0%.
Directional only
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 3 Flash Preview
Gemini 3.8 Flash $0.0026, Gemini 3 Flash Preview $0.0020 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Gemini 3 Flash Preview
Gemini 3.8 Flash $2.74, Gemini 3 Flash Preview $0.37.
Published attempt cost and pass rate
At a glance
- Coding index
- Gemini 3.8 Flash 61.6 from 6 benchmarks, Gemini 3 Flash Preview 43.7 from 2 benchmarks.
- Widest category
- Agentic work, 18.8 points apart on average over 11 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Gemini 3.8 Flash 78.7% against Gemini 3 Flash Preview 20.2%, 58.5 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.8 Flash $3.75 against Gemini 3 Flash Preview $3.00 per million output tokens, 1.3x apart.
- Context window
- Both take 1.05M tokens.
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 | Gemini 3 Flash Preview | Ties |
|---|---|---|---|---|
| Coding | 7 | 2 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 11 | 0 | ||
| Reasoning | 9 | 0 | ||
| Math | 4 | 0 | ||
| Knowledge | 5 | 2 | ||
| Web design | 4 | 0 | ||
| General | 4 | 1 | ||
| All shared boards | 45 | 5 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index72
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | Leader |
|---|---|---|---|
| SWE-bench Verified | Not measured | 75.8% | Only Gemini 3 Flash Preview measured |
| 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% | 85.6% | Gemini 3.8 Flash |
| SWE-bench Verified (Vals AI) | 80.0% | 75.0% | Gemini 3.8 Flash |
| Terminal-Bench 4 (Vals AI) | 19.7% | Not measured | Only Gemini 3.8 Flash measured |
| Vibe Code Bench (Vals AI) | 78.7% | 20.2% | Gemini 3.8 Flash |
| Code migration (Vals AI) | 36.5% | 6.4% | Gemini 3.8 Flash |
| ProgramBench (Vals AI) | 1.0% | 0.0% | Gemini 3.8 Flash |
| IOI (Vals AI) | 56.9% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench 2.1 (Vals AI) | 81.3% | 53.9% | Gemini 3.8 Flash |
| 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 |
| LiveCodeBench (Artificial Analysis run) | Not measured | 90.8% | Only Gemini 3 Flash Preview measured |
| SciCode | 56.6% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 38.6% | Only Gemini 3 Flash Preview measured |
| Terminal-Bench | Not measured | 64.3% | Only Gemini 3 Flash Preview measured |
| FrontierCode | 41.2% | Not measured | Only Gemini 3.8 Flash measured |
| FrontierSWE | 19.6% | Not measured | Only Gemini 3.8 Flash measured |
| GSO-Bench | Not measured | 9.8% | Only Gemini 3 Flash Preview measured |
| WeirdML | 84.8% | 61.6% | Gemini 3.8 Flash |
| ALE-Bench | 1269.7 | 1367.2 | Gemini 3 Flash Preview |
| LMArena Text: coding | 1508 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: software and IT | 1507 | Not measured | Only Gemini 3.8 Flash measured |
| 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 |
| SciCode | 12.3% | 12.7% | Gemini 3 Flash Preview |
| Neither model has a result on the other 8 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 40.9 | 26.3 | Gemini 3.8 Flash |
| Epoch Capabilities Index | 157.4 | Not measured | Only Gemini 3.8 Flash measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index110
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | Leader |
|---|---|---|---|
| AA Agentic Index | 40.2 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building web apps | 1238 | 1110 | Gemini 3.8 Flash |
| Design Arena: agents building full-stack apps | 1244 | 1063 | Gemini 3.8 Flash |
| Design Arena: agents building mobile apps | 1236 | 1090 | Gemini 3.8 Flash |
| Design Arena: agents building Android apps | 1074 | 1050 | Gemini 3.8 Flash |
| Design Arena: agents building Godot games | 1273 | 1161 | Gemini 3.8 Flash |
| Design Arena: PowerPoint slides | 1177 | 1036 | Gemini 3.8 Flash |
| Design Arena: spreadsheets | 1056 | 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% | 42.5% | Gemini 3.8 Flash |
| Tax Agent Bench (Vals AI) | 32.1% | 11.8% | Gemini 3.8 Flash |
| Legal Research Bench (Vals AI) | 38.9% | 18.3% | Gemini 3.8 Flash |
| Harvey's Legal Agent Benchmark (Vals AI) | 12.1% | Not measured | Only Gemini 3.8 Flash measured |
| Excel Modeling Benchmark (Vals AI) | 72.2% | 26.0% | Gemini 3.8 Flash |
| 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 | 80.4% | Only Gemini 3 Flash Preview 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 |
| BALROG | Not measured | 48.1% | Only Gemini 3 Flash Preview measured |
| DeepResearch Bench | Not measured | 49.8% | Only Gemini 3 Flash Preview measured |
| Vending-Bench 2 | $5,094 | $3,635 | Gemini 3.8 Flash |
| Neither model has a result on the other 13 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index90
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | Leader |
|---|---|---|---|
| GPQA Diamond | 94.4% | 87.9% | Gemini 3.8 Flash |
| 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% | 87.6% | Gemini 3.8 Flash |
| GPQA Diamond (Artificial Analysis run) | 95.3% | 89.8% | Gemini 3.8 Flash |
| Humanity's Last Exam (Artificial Analysis run) | 47.8% | 36.6% | Gemini 3.8 Flash |
| GPQA Diamond (Epoch AI run) | 95.4% | 89.4% | Gemini 3.8 Flash |
| ARC-AGI | 98.5% | 84.7% | Gemini 3.8 Flash |
| ARC-AGI-2 | 89.2% | 33.6% | Gemini 3.8 Flash |
| SimpleBench | Not measured | 61.1% | Only Gemini 3 Flash Preview measured |
| Chess puzzles | 58.0% | 39.0% | Gemini 3.8 Flash |
| Mystery game puzzles | 47.0% | 26.0% | Gemini 3.8 Flash |
| VPCT | Not measured | 72.6% | Only Gemini 3 Flash Preview measured |
| LMArena Text: hard prompts | 1509 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: expert | 1526 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: hard prompts in English | 1504 | Not measured | Only Gemini 3.8 Flash measured |
| 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 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | Leader |
|---|---|---|---|
| AIME | Not measured | 95.6% | Only Gemini 3 Flash Preview measured |
| MGSM (Vals AI) | Not measured | 93.3% | Only Gemini 3 Flash Preview measured |
| AA Math Index | Not measured | 97.0 | Only Gemini 3 Flash Preview measured |
| AIME 2025 (Artificial Analysis run) | Not measured | 97.0% | Only Gemini 3 Flash Preview measured |
| OTIS Mock AIME | 98.9% | 95.6% | Gemini 3.8 Flash |
| FrontierMath, tiers 1 to 3 | 68.4% | 51.2% | Gemini 3.8 Flash |
| FrontierMath, tier 4 | 22.0% | 17.1% | Gemini 3.8 Flash |
| ProofBench | 48.0% | 15.0% | Gemini 3.8 Flash |
| LMArena Text: math | 1532 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: mathematical work | 1519 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index52
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | Leader |
|---|---|---|---|
| MMLU Pro | 90.2% | 88.6% | Gemini 3.8 Flash |
| LegalBench (Vals AI) | 87.0% | 86.9% | Gemini 3.8 Flash |
| CaseLaw (Vals AI) | Not measured | 55.8% | Only Gemini 3 Flash Preview measured |
| CorpFin (Vals AI) | Not measured | 66.4% | Only Gemini 3 Flash Preview measured |
| TaxEval (Vals AI) | 74.5% | 73.9% | Gemini 3.8 Flash |
| MortgageTax (Vals AI) | 65.3% | 68.7% | Gemini 3 Flash Preview |
| MedQA (Vals AI) | Not measured | 95.8% | Only Gemini 3 Flash Preview measured |
| MedCode (Vals AI) | 48.1% | 55.9% | Gemini 3 Flash Preview |
| MMLU Pro (Artificial Analysis run) | Not measured | 89.0% | Only Gemini 3 Flash Preview measured |
| SimpleQA Verified | 69.7% | 66.8% | Gemini 3.8 Flash |
| GeoBench | Not measured | 88.0% | Only Gemini 3 Flash Preview measured |
| LMArena Text: science | 1523 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: medicine and healthcare | 1508 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: legal and government | 1497 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: business and finance | 1479 | Not measured | Only Gemini 3.8 Flash measured |
| FACTS Benchmark Suite | 69.4% | 63.4% | Gemini 3.8 Flash |
| Neither model has a result on the other 2 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | Leader |
|---|---|---|---|
| Design Arena: websites | 1300 | 1196 | Gemini 3.8 Flash |
| Design Arena: UI components | 1319 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: game dev | 1305 | 1166 | Gemini 3.8 Flash |
| Design Arena: data viz | 1269 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: 3D | 1295 | 1184 | Gemini 3.8 Flash |
| Design Arena: all code categories | 1304 | 1189 | Gemini 3.8 Flash |
| Design Arena: SVG | 1295 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: ASCII art | 1265 | 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 index41
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | 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% | 51.8% | Gemini 3 Flash Preview |
| MedScribe (Vals AI) | 84.5% | 69.9% | Gemini 3.8 Flash |
| Vals Multimodal Index | Not measured | 52.2% | Only Gemini 3 Flash Preview measured |
| IFBench | Not measured | 78.0% | Only Gemini 3 Flash Preview measured |
| Long context reasoning (AA-LCR) | 84.0% | 78.0% | Gemini 3.8 Flash |
| DTBench | 95.7% | 89.1% | Gemini 3.8 Flash |
| LMCA | 52.9% | 43.1% | Gemini 3.8 Flash |
| 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 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: instruction following | 1492 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: creative writing | 1488 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision | 1315 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: English | 1498 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: non-English | 1491 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Chinese | 1553 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: German | 1501 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Japanese | 1507 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Korean | 1464 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: French | 1496 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Spanish | 1487 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Russian | 1514 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Polish | 1497 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: multi-turn | 1503 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: longer queries | 1507 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: writing and language | 1494 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: entertainment and media | 1480 | Not measured | Only Gemini 3.8 Flash measured |
| 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 11 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3.8 Flash | Gemini 3 Flash Preview | 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
Gemini 3 Flash Preview$0.0020Fits in one request
Gemini 3 Flash Preview costs less
Repository review
50K input + 3K output tokens
Gemini 3.8 Flash$0.049Fits in one request
Gemini 3 Flash Preview$0.034Fits in one request
Gemini 3 Flash Preview costs less
Agent loop
200K input + 10K output tokens
Gemini 3.8 Flash$0.188Fits in one request
Gemini 3 Flash Preview$0.130Fits in one request
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 3.8 Flash | Google Gemini 3 Flash Preview |
|---|---|---|
| Maker | ||
| Weights | No public weights listed | No public weights listed |
| Released | September 2, 2026 | December 17, 2025 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.75 | $0.50 |
| Output $/Mtok | $3.75 | $3.00 |
| Coding index | 61.6 | 43.7 |
| Independent measurements behind it | 6 | 2 |
| Cost per solved task | $2.74 | $0.37 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.8 Flash better than Gemini 3 Flash Preview for coding?
Pick Gemini 3.8 Flash for coding: it scores 61.6 on the Vibe Coding Index against 43.7 for Gemini 3 Flash Preview. Pick Gemini 3 Flash Preview for output tokens 1.3x cheaper ($3.00 vs $3.75 per million) and a lower cost per solved task ($0.37 against $2.74).
Which is cheaper, Gemini 3.8 Flash or Gemini 3 Flash Preview?
Gemini 3.8 Flash costs $0.75 per million input tokens and $3.75 per million output tokens; Gemini 3 Flash Preview costs $0.50 and $3.00. Per solved SWE-bench Verified task, Gemini 3.8 Flash costs $2.74 and Gemini 3 Flash Preview $0.37.
Which has the bigger context window, Gemini 3.8 Flash or Gemini 3 Flash Preview?
Neither: both take 1.05M tokens.
How many benchmarks is the Gemini 3.8 Flash vs Gemini 3 Flash Preview comparison based on?
50 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 Gemini 3 Flash Preview's on 2. Where only one model has a result, the page says so instead of naming a winner.