Gemini 2.5 Flash Lite vs Gemini 3.1 Flash Lite Preview
Gemini 3.1 Flash Lite Preview leads Gemini 2.5 Flash Lite on the Artificial Analysis Intelligence Index, 15.6 to 10.4, and Gemini 2.5 Flash Lite costs 3.8x less per output token ($0.40 vs $1.50 per million). Updated October 21, 2026; 13 benchmarks have a result for both.
Gemini 2.5 Flash Lite or Gemini 3.1 Flash Lite Preview: which to pick
Only Gemini 3.1 Flash Lite Preview has a coding score, 22.7 on the Vibe Coding Index; Gemini 2.5 Flash Lite has none, so the two cannot be ranked on coding.
Pick Gemini 2.5 Flash Lite for output tokens 3.8x cheaper ($0.40 vs $1.50 per million) and work measured by MedScribe (Vals AI), where it leads.
- Shared results
- 13
- Gemini 2.5 Flash Lite only
- 17
- Gemini 3.1 Flash Lite Preview only
- 66
- Like-for-like categories
- 6 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 3.1 Flash Lite Preview has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Gemini 3.1 Flash Lite Preview
Gemini 3.1 Flash Lite Preview leads, 15.6 against 10.4.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Gemini 3.1 Flash Lite Preview has a AA Agentic Index result, 1.6.
Directional only
Reasoning
GPQA Diamond
Gemini 3.1 Flash Lite Preview
Gemini 3.1 Flash Lite Preview leads, 81.1% against 70.2%.
Same board, both measured
Math
AIME
Gemini 3.1 Flash Lite Preview
Gemini 3.1 Flash Lite Preview leads, 83.3% against 42.1%.
Same board, both measured
Knowledge
MMLU Pro
Gemini 3.1 Flash Lite Preview
Gemini 3.1 Flash Lite Preview leads, 86.2% against 79.1%.
Same board, both measured
Web design
Design Arena: websites
No call
Only Gemini 3.1 Flash Lite Preview has a Design Arena: websites result, 1083.
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 2.5 Flash Lite
Gemini 2.5 Flash Lite $0.0003, Gemini 3.1 Flash Lite Preview $0.0010 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3.1 Flash Lite Preview has the number, $0.18.
Directional only
At a glance
- Coding index
- Gemini 2.5 Flash Lite not benchmarked, Gemini 3.1 Flash Lite Preview 22.7 from 3 benchmarks.
- Widest category
- Math, 41.3 points apart on average over 1 shared benchmark.
- Widest single gap
- AIME: Gemini 2.5 Flash Lite 42.1% against Gemini 3.1 Flash Lite Preview 83.3%, 41.3 points apart on a 0 to 100 scale.
- Output price
- Gemini 2.5 Flash Lite $0.40 against Gemini 3.1 Flash Lite Preview $1.50 per million output tokens, 3.8x 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 2.5 Flash Lite | Bars | Gemini 3.1 Flash Lite Preview | Ties |
|---|---|---|---|---|
| Coding | 0 | 1 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 0 | 2 | ||
| Math | 0 | 1 | ||
| Knowledge | 0 | 6 | ||
| General | 1 | 1 | ||
| All shared boards | 1 | 12 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index01
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1257 | Only Gemini 3.1 Flash Lite Preview measured |
| AA Coding Index | Not measured | 34.7 | Only Gemini 3.1 Flash Lite Preview measured |
| LiveCodeBench (Vals AI) | 71.4% | 80.1% | Gemini 3.1 Flash Lite Preview |
| SWE-bench Verified (Vals AI) | Not measured | 62.8% | Only Gemini 3.1 Flash Lite Preview measured |
| Vibe Code Bench (Vals AI) | Not measured | 0.0% | Only Gemini 3.1 Flash Lite Preview measured |
| Code migration (Vals AI) | Not measured | 4.6% | Only Gemini 3.1 Flash Lite Preview measured |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Gemini 3.1 Flash Lite Preview measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 34.1% | Only Gemini 3.1 Flash Lite Preview measured |
| LiveCodeBench (Artificial Analysis run) | 59.3% | Not measured | Only Gemini 2.5 Flash Lite measured |
| Terminal-Bench Hard (Artificial Analysis run) | 4.5% | Not measured | Only Gemini 2.5 Flash Lite measured |
| ALE-Bench | Not measured | 797.7 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: coding | Not measured | 1400 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: software and IT | Not measured | 1413 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena WebDev: React | Not measured | 1245 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena WebDev: HTML | Not measured | 1276 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena WebDev: from an image | Not measured | 1336 | Only Gemini 3.1 Flash Lite Preview measured |
| SciCode | Not measured | 4.6% | Only Gemini 3.1 Flash Lite Preview measured |
| Neither model has a result on the other 22 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 10.4 | 15.6 | Gemini 3.1 Flash Lite Preview |
| Epoch Capabilities Index | 133.8 | Not measured | Only Gemini 2.5 Flash Lite measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 1.6 | Only Gemini 3.1 Flash Lite Preview measured |
| Finance Agent (Vals AI) | Not measured | 30.0% | Only Gemini 3.1 Flash Lite Preview measured |
| Tax Agent Bench (Vals AI) | Not measured | 3.1% | Only Gemini 3.1 Flash Lite Preview measured |
| Legal Research Bench (Vals AI) | Not measured | 3.4% | Only Gemini 3.1 Flash Lite Preview measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 8.6% | Only Gemini 3.1 Flash Lite Preview measured |
| τ²-Bench Telecom | 19.0% | Not measured | Only Gemini 2.5 Flash Lite measured |
| Berkeley Function Calling Leaderboard (BFCL) | 36.9% | Not measured | Only Gemini 2.5 Flash Lite measured |
| Neither model has a result on the other 34 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| GPQA Diamond | 70.2% | 81.1% | Gemini 3.1 Flash Lite Preview |
| MMMU Pro (Vals AI) | 75.4% | 82.5% | Gemini 3.1 Flash Lite Preview |
| GPQA Diamond (Artificial Analysis run) | 62.5% | Not measured | Only Gemini 2.5 Flash Lite measured |
| Humanity's Last Exam (Artificial Analysis run) | 6.8% | Not measured | Only Gemini 2.5 Flash Lite measured |
| LMArena Text: hard prompts | Not measured | 1407 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: expert | Not measured | 1398 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: hard prompts in English | Not measured | 1403 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: diagrams | Not measured | 1242 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: homework | Not measured | 1271 | Only Gemini 3.1 Flash Lite Preview measured |
| Kagi LLM Benchmark | 40.5% | Not measured | Only Gemini 2.5 Flash Lite measured |
| Neither model has a result on the other 12 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| AIME | 42.1% | 83.3% | Gemini 3.1 Flash Lite Preview |
| MGSM (Vals AI) | 89.5% | Not measured | Only Gemini 2.5 Flash Lite measured |
| AA Math Index | 53.3 | Not measured | Only Gemini 2.5 Flash Lite measured |
| AIME 2025 (Artificial Analysis run) | 53.3% | Not measured | Only Gemini 2.5 Flash Lite measured |
| LMArena Text: math | Not measured | 1428 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: mathematical work | Not measured | 1417 | Only Gemini 3.1 Flash Lite Preview measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| MMLU Pro | 79.1% | 86.2% | Gemini 3.1 Flash Lite Preview |
| LegalBench (Vals AI) | 82.0% | 83.8% | Gemini 3.1 Flash Lite Preview |
| CaseLaw (Vals AI) | Not measured | 55.0% | Only Gemini 3.1 Flash Lite Preview measured |
| CorpFin (Vals AI) | 57.6% | 59.4% | Gemini 3.1 Flash Lite Preview |
| TaxEval (Vals AI) | 66.2% | 71.8% | Gemini 3.1 Flash Lite Preview |
| MortgageTax (Vals AI) | 57.6% | 68.0% | Gemini 3.1 Flash Lite Preview |
| MedQA (Vals AI) | 88.9% | Not measured | Only Gemini 2.5 Flash Lite measured |
| MedCode (Vals AI) | 34.2% | 47.6% | Gemini 3.1 Flash Lite Preview |
| MMLU Pro (Artificial Analysis run) | 75.9% | Not measured | Only Gemini 2.5 Flash Lite measured |
| LMArena Text: science | Not measured | 1425 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: medicine and healthcare | Not measured | 1428 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: legal and government | Not measured | 1418 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: business and finance | Not measured | 1389 | Only Gemini 3.1 Flash Lite Preview measured |
| FACTS Benchmark Suite | Not measured | 51.4% | Only Gemini 3.1 Flash Lite Preview 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 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1083 | Only Gemini 3.1 Flash Lite Preview measured |
| Design Arena: UI components | Not measured | 1072 | Only Gemini 3.1 Flash Lite Preview measured |
| Design Arena: game dev | Not measured | 1029 | Only Gemini 3.1 Flash Lite Preview measured |
| Design Arena: data viz | Not measured | 1045 | Only Gemini 3.1 Flash Lite Preview measured |
| Design Arena: 3D | Not measured | 1048 | Only Gemini 3.1 Flash Lite Preview measured |
| Design Arena: all code categories | Not measured | 1072 | Only Gemini 3.1 Flash Lite Preview measured |
| Design Arena: SVG | Not measured | 1052 | Only Gemini 3.1 Flash Lite Preview measured |
| Design Arena: ASCII art | Not measured | 1167 | Only Gemini 3.1 Flash Lite Preview measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite Preview | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 30.8% | 49.5% | Gemini 3.1 Flash Lite Preview |
| MedScribe (Vals AI) | 75.8% | 63.9% | Gemini 2.5 Flash Lite |
| Vals Multimodal Index | Not measured | 41.4% | Only Gemini 3.1 Flash Lite Preview measured |
| IFBench | 49.9% | Not measured | Only Gemini 2.5 Flash Lite measured |
| Long context reasoning (AA-LCR) | 55.7% | Not measured | Only Gemini 2.5 Flash Lite measured |
| DTBench | 62.8% | Not measured | Only Gemini 2.5 Flash Lite measured |
| LMCA | 18.1% | Not measured | Only Gemini 2.5 Flash Lite measured |
| LMArena Text | Not measured | 1416 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: instruction following | Not measured | 1377 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: creative writing | Not measured | 1401 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision | Not measured | 1240 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: English | Not measured | 1414 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: non-English | Not measured | 1410 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: Chinese | Not measured | 1460 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: German | Not measured | 1430 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: Japanese | Not measured | 1413 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: Korean | Not measured | 1392 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: French | Not measured | 1424 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: Spanish | Not measured | 1421 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: Russian | Not measured | 1420 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: Polish | Not measured | 1443 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: multi-turn | Not measured | 1417 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: longer queries | Not measured | 1394 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: writing and language | Not measured | 1408 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Text: entertainment and media | Not measured | 1386 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: English | Not measured | 1232 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: Chinese | Not measured | 1278 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: reading text | Not measured | 1246 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: humor | Not measured | 1266 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: captioning | Not measured | 1259 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: recognizing things | Not measured | 1308 | Only Gemini 3.1 Flash Lite Preview measured |
| LMArena Vision: creative writing | Not measured | 1248 | Only Gemini 3.1 Flash Lite Preview measured |
| Neither model has a result on the other 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 2.5 Flash Lite | Gemini 3.1 Flash Lite 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 2.5 Flash Lite costs less
Repository review
50K input + 3K output tokens
Gemini 2.5 Flash Lite costs less
Agent loop
200K input + 10K output tokens
Gemini 2.5 Flash Lite 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 2.5 Flash Lite | Google Gemini 3.1 Flash Lite Preview |
|---|---|---|
| Maker | ||
| Weights | No public weights listed | No public weights listed |
| Released | July 22, 2025 | March 3, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.10 | $0.25 |
| Output $/Mtok | $0.40 | $1.50 |
| Coding index | Not benchmarked | 22.7 |
| Independent measurements behind it | 0 | 3 |
| Cost per solved task | Not computable | $0.18 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 2.5 Flash Lite better than Gemini 3.1 Flash Lite Preview for coding?
Only Gemini 3.1 Flash Lite Preview has a coding score, 22.7 on the Vibe Coding Index; Gemini 2.5 Flash Lite has none, so the two cannot be ranked on coding. Pick Gemini 2.5 Flash Lite for output tokens 3.8x cheaper ($0.40 vs $1.50 per million) and work measured by MedScribe (Vals AI), where it leads.
Which is cheaper, Gemini 2.5 Flash Lite or Gemini 3.1 Flash Lite Preview?
Gemini 2.5 Flash Lite costs $0.10 per million input tokens and $0.40 per million output tokens; Gemini 3.1 Flash Lite Preview costs $0.25 and $1.50. Cost per solved task is known for Gemini 3.1 Flash Lite Preview only.
Which has the bigger context window, Gemini 2.5 Flash Lite or Gemini 3.1 Flash Lite Preview?
Neither: both take 1.05M tokens.
How many benchmarks is the Gemini 2.5 Flash Lite vs Gemini 3.1 Flash Lite Preview comparison based on?
13 benchmarks have a result for both models as of October 21, 2026. Gemini 2.5 Flash Lite's coding index rests on 0 independent benchmarks and Gemini 3.1 Flash Lite Preview's on 3. Where only one model has a result, the page says so instead of naming a winner.