Model comparison
Gemini 3.1 Pro vs Gemini 3.5 Flash-Lite
Two Google tiers compared on the figures that decide which one a workload actually needs.
Catalog record checked August 9, 2026; individual provider fields may change.
Gemini 3.1 Pro
Frontier
Gemini 3.5 Flash-Lite
Budget
| Specification | Gemini 3.1 Pro | Gemini 3.5 Flash-Lite |
|---|---|---|
| Provider | ||
| Tier | Frontier | Budget |
| Context window | 1.05M | 1.05M |
| Max output | 66K | 66K |
| Input / 1M tokens | $2 | Winner: $0.30 |
| Output / 1M tokens | $12 | Winner: $2.50 |
| Weights | Closed | Closed |
| Parameters | Not disclosed | Not disclosed |
| Reasoning levels | Not verified | Not verified |
| Modalities | text, image, video, audio, pdf | text, image, video, audio, pdf |
| Released | February 19, 2026 | July 21, 2026 |
| Artificial Analysis Intelligence Index (2026-08-09) | Winner: 48 | 37 |
Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.
Pricing tiers: Gemini 3.1 Pro: Base tier is $2/$12 per million tokens; prompts above 200K tokens are priced at $4/$18. Prefer the Preview API id `gemini-3.1-pro-preview` (not a GA alias).
Gemini 3.1 Pro
Google's Pro tier in limited preview since 2026-02-19, with a 1.05M-token context window and multimodal input.
Best for
- Very long documents
- Multimodal input
- Google Workspace integration
Watch out
Scored 12% on DeepSWE, far below every other model here including budget tiers — weak on agentic coding specifically. Pricing also steps up to $4/$18 above 200K tokens. Wire calls to `gemini-3.1-pro-preview`.
Gemini 3.5 Flash-Lite
Google's cheapest current Flash-class API tier for high-volume, latency-sensitive agent loops.
Best for
- High-volume agents
- Document pipelines
- Cost-sensitive multimodal work
Watch out
Cheaper than 3.6 and 3.7 Flash, not stronger on hard reasoning — pick it for throughput, not frontier coding.
Benchmark
DeepSWE 1.1 in context
Only Gemini 3.1 Pro has a published DeepSWE 1.1 result. It is shown against the wider field, with cost per completed task alongside the score.
Local leader
Claude Opus 5 [max]
74%
Rows shown
24
Highest published reasoning effort per model (not best Pass@1)
Snapshot date
2026-08-13
Mirrored from deepswe.datacurve.ai
Better is toward the top-right (higher pass rate, lower cost). X-axis is reversed to match DeepSWE’s public chart. v1.1 uses average cost / tokens / steps; v1 uses published medians.
| # | Model | Pass@1 | Cost / task | Tokens / task | Steps / task |
|---|---|---|---|---|---|
| 1 | Claude Opus 5 [max] | 74% | $11.84 | 118k | 99 |
| 2 | GPT-5.6 Sol [max] | 73% | $8.39 | 60k | 61 |
| 3 | Claude Fable 5 [max] | 70% | $21.63 | 119k | 88 |
| 4 | GPT-5.6 Terra [max] | 70% | $4.95 | 72k | 76 |
| 5 | Kimi K3 [max] | 69% | $4.65 | 82k | 98 |
| 6 | GPT-5.6 Luna [max] | 67% | $3.03 | 73k | 102 |
| 7 | GPT-5.5 [xhigh] | 67% | $7.23 | 46k | 82 |
| 8 | Grok 4.6 [xhigh] | 67% | $5.50 | 71k | 87 |
| 9 | Gemini 3.7 Flash [high] | 65% | $2.18 | 107k | 125 |
| 10 | DeepSeek V4-Pro [max] | 63% | $0.24 | 106k | 155 |
| 11 | Claude Opus 4.8 [max] | 59% | $13.22 | 135k | 120 |
| 12 | Qwen3.8-Max [xhigh] | 58% | $3.73 | 95k | 111 |
| 13 | Muse Spark 1.2 [xhigh] | 55% | $3.70 | 99k | 101 |
| 14 | Claude Sonnet 5 [max] | 54% | $26.40 | 214k | 268 |
| 15 | Grok 4.5 [high] | 54% | $2.42 | 36k | 61 |
| 16 | DeepSeek V4-Flash [max] | 53% | $0.10 | 108k | 153 |
| 17 | Muse Spark 1.1 [xhigh] | 53% | $2.36 | 74k | 96 |
| 18 | GPT-5.4 [xhigh] | 52% | $5.65 | 71k | 70 |
| 19 | Gemini 3.6 Flash [high] | 47% | $4.42 | 96k | 117 |
| 20 | GLM 5.2 [max] | 44% | $3.92 | 78k | 129 |
| 21 | Gemini 3.5 Flash [high] | 36% | $3.45 | 76k | 105 |
| 22 | Kimi K2.7 Code | 31% | $2.82 | 59k | 149 |
| 23 | Claude Sonnet 4.6 [high] | 30% | $5.52 | 76k | 134 |
| 24 | Gemini 3.1 Pro [high] | 12% | $2.14 | 28k | 76 |
DeepSWE “Best” picks the highest published reasoning effort per model (not the highest pass rate). Small gaps may not be statistically meaningful — confirm on deepswe.datacurve.ai.
Common questions
Gemini 3.1 Pro vs Gemini 3.5 Flash-Lite
Answered from the verified figures on this page rather than general guidance.
Is Gemini 3.1 Pro or Gemini 3.5 Flash-Lite cheaper for input?
Gemini 3.5 Flash-Lite is cheaper at $0.30 per million input tokens, against $2 for Gemini 3.1 Pro — roughly 6.7× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Gemini 3.1 Pro has tiered pricing: Base tier is $2/$12 per million tokens; prompts above 200K tokens are priced at $4/$18. Prefer the Preview API id `gemini-3.1-pro-preview` (not a GA alias).
Is Gemini 3.1 Pro or Gemini 3.5 Flash-Lite cheaper for output?
Gemini 3.5 Flash-Lite is cheaper at $2.50 per million output tokens, against $12 for Gemini 3.1 Pro — roughly 4.8× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Gemini 3.1 Pro has tiered pricing: Base tier is $2/$12 per million tokens; prompts above 200K tokens are priced at $4/$18. Prefer the Preview API id `gemini-3.1-pro-preview` (not a GA alias).
Which has the larger context window, Gemini 3.1 Pro or Gemini 3.5 Flash-Lite?
Both accept about 1.05M tokens of context, so document length will not decide between them.
Should I use Gemini 3.1 Pro or Gemini 3.5 Flash-Lite?
Gemini 3.1 Pro is the frontier tier and Gemini 3.5 Flash-Lite the budget tier. The useful question is whether your hardest task actually fails on the cheaper one — most production volume such as classification, extraction and summarisation does not.
Next step
Choosing between them
Tier and workload decide this more reliably than a leaderboard position does.
If both sit in the same tier, the decision usually comes down to context window and output price rather than headline capability — output tokens dominate real bills.
If one is a step up within the same provider, the useful question is whether your hardest task actually fails on the cheaper tier. Most production volume — classification, extraction, summarization — does not.
Choosing a harness rather than a model — Cursor, Copilot, Claude Code, Muse Code, or Lovable? Compare agentic harnesses · Latest releases.