Compare / Gemini 3.1 Flash-Lite Preview vs Gemini 3.5 Flash-Lite
Gemini 3.1 Flash-Lite Preview vs Gemini 3.5 Flash-Lite
Which is cheaper, which is more capable, and which does better at each kind of work, from 16 results on 2 sources that measured both models.
Results as of 8 October 2026 (catalogue release 2026-10-08-4199ce0620fe).
Gemini 3.1 Flash-Lite Preview or Gemini 3.5 Flash-Lite? The short answer
Gemini 3.5 Flash-Lite is the newer version and scores higher (Intelligence Index 22.2 against 15.6), but Gemini 3.1 Flash-Lite Preview is cheaper (34% less per token): upgrade if the gain is worth the price.
- Gemini 3.1 Flash-Lite Preview is cheaper: $0.56 against $0.85 per million tokens, 34% less.
- Gemini 3.5 Flash-Lite scores higher on the Artificial Analysis Intelligence Index: 22.2 against 15.6.
- Gemini 3.5 Flash-Lite is newer: released 21 Jul 2026, against 3 Mar 2026 for Gemini 3.1 Flash-Lite Preview.
- On third-party benchmarks, on the results both models have: Gemini 3.5 Flash-Lite does better for agents and tool use, reasoning and knowledge, writing and sticking to the facts.
At a glance
| Gemini 3.1 Flash-Lite Preview | Gemini 3.5 Flash-Lite | |
|---|---|---|
| Price per million tokens | $0.25 in · $1.50 out | $0.30 in · $2.50 out |
| Blended (3 in : 1 out) | $0.56 | $0.85 |
| Cheapest host, blended | – | $0.85 (Google) |
| Cached input, per million | – | $0.030 cached input |
| Intelligence Index | 15.6 | 22.2 |
| Spring Prompt overall | – | 27 |
| Output speed, tokens a second | – | 335 |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Released | 3 Mar 2026 | 21 Jul 2026 (newer) |
| Weights | Closed | Closed |
| Developer based in | the US | the US |
Prices are the developer's list price where we have read it, otherwise the typical host on OpenRouter; see every model's price. Intelligence and speed from Artificial Analysis.
Which is better for what
Each model's rank among models available today, for each kind of work, from our own benchmarks and licensed sources. The better rank is in green.
| Use case | Gemini 3.1 Flash-Lite Preview | Gemini 3.5 Flash-Lite |
|---|---|---|
| Product listingsTurning a sparse product feed and photos into listings that can go live | not measured | 16 of 20 |
| Decks from an analysisTurning a finished analysis into a deck you could present as it is | not measured | 17 of 19 |
| User surveysPlanning a user survey and reading its results without being misled | not measured | 6 of 8 |
| Marketing planningPlanning a year of ad spend without overspending | not measured | 15 of 19 |
| Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls | 98 of 164 | 73 of 164 |
| Professional workReal tasks from banking, consulting and law, business documents and freelance projects | not measured | 46 of 51 |
| Reasoning and knowledgeHard questions across science, maths and general knowledge | 103 of 198 | 91 of 198 |
| WritingWhat people prefer in blind comparisons, and judged writing quality | 80 of 188 | 49 of 188 |
| Sticking to the factsSummarising without inventing things, and factual answers | 74 of 152 | 62 of 152 |
| Speed under pressureGood decisions against a real clock (fast chess) | not measured | 2 of 22 |
From our research
Every shared result
Each model's best result on every measure both have, grouped by benchmark, with the setting that produced it. The headline measures of each benchmark come first; the rest are under "Show all". Green marks the better value; where a source reports ranges that overlap, neither is marked.
| Measure | Gemini 3.1 Flash-Lite Preview | Gemini 3.5 Flash-Lite |
|---|---|---|
| Arena (formerly LMArena) reported by Arena (formerly LMArena) · 3 results | ||
| Overall · TextArena rating, higher is better | 1,433 | 1,455 |
| Overall · Text factualityArena rating, higher is better | 1,433 | 1,447 |
| Business, management and finance · TextArena rating, higher is better | 1,420 | 1,452 |
| Artificial Analysis reported by Artificial Analysis · 3 results | ||
| Artificial Analysis Intelligence Indexindex score, higher is better | 15.6 | 22.2 |
| GPQA Diamond% of questions, higher is better | 82.2% | 83.8% |
| Humanity's Last Exam% of questions, higher is better | 17.2% | 18.8% |
Show all 16 results (10 more)
| Measure | Gemini 3.1 Flash-Lite Preview | Gemini 3.5 Flash-Lite |
|---|---|---|
| Arena (formerly LMArena) reported by Arena (formerly LMArena) · 4 results | ||
| Creative writing · TextArena rating, higher is better | 1,413 | 1,436 |
| Expert prompts · TextArena rating, higher is better | 1,443 | 1,470 |
| Instruction following · TextArena rating, higher is better | 1,407 | 1,443 |
| Writing, literature and language · TextArena rating, higher is better | 1,420 | 1,443 |
| Artificial Analysis reported by Artificial Analysis · 6 results | ||
| Terminal-Bench 2.1% of tasks, higher is better | 31.1% | 53.6% |
| Terminal-Bench 4.0% of tasks, higher is better | 0.5% | 1.0% |
| τ-bench banking% of tasks, higher is better | 9.7% | 17.5% |
| Artificial Analysis Coding Indexindex score, higher is better | 34.7 | 49.3 |
| Long-context reasoning (AA-LCR)% of questions, higher is better | 74.3% | 76.0% |
| SciCode% of problems, higher is better | 43.4% | 41.3% |
Quick answers
Is Gemini 3.1 Flash-Lite Preview better than Gemini 3.5 Flash-Lite?
Gemini 3.5 Flash-Lite is the newer version and scores higher (Intelligence Index 22.2 against 15.6), but Gemini 3.1 Flash-Lite Preview is cheaper (34% less per token): upgrade if the gain is worth the price.
Which is cheaper, Gemini 3.1 Flash-Lite Preview or Gemini 3.5 Flash-Lite?
Gemini 3.1 Flash-Lite Preview is cheaper: $0.56 against $0.85 per million tokens, 34% less.
Run Gemini 3.1 Flash-Lite Preview and Gemini 3.5 Flash-Lite on your own prompt
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