Gemini 3.1 Flash Lite vs GPT-5.6 Luna Pro
GPT-5.6 Luna Pro costs 1.3x less per output token than Gemini 3.1 Flash Lite ($1.20 vs $1.50 per million). Updated October 22, 2026; no benchmark has tested both models yet.
- Coding
- No data
- Overall
- No data
- Output $/M
- $1.50
- Coding
- No data
- Overall
- No data
- Output $/M
- $1.20
Gemini 3.1 Flash Lite or GPT-5.6 Luna Pro: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Compare them on price, context and the boards below.
No benchmark has tested both yet. Gemini 3.1 Flash Lite has results on SciCode, Terminal-Bench Hard (Artificial Analysis run) and WeirdML; GPT-5.6 Luna Pro has none yet. Compare them on price and context instead.
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
Neither has a coding score yet.
One side not measured
Long documents
Listed context window
GPT-5.6 Luna Pro
GPT-5.6 Luna Pro takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.6 Luna Pro
Gemini 3.1 Flash Lite $0.0010, GPT-5.6 Luna Pro $0.0008 per turn.
List prices
At a glance
- Coding index
- Gemini 3.1 Flash Lite not benchmarked, GPT-5.6 Luna Pro not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- Gemini 3.1 Flash Lite $1.50 against GPT-5.6 Luna Pro $1.20 per million output tokens, 1.3x apart.
- Context window
- Gemini 3.1 Flash Lite takes 1.05M tokens, GPT-5.6 Luna Pro 1.05M.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index3 boards measured
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.6 Luna Pro | Leader |
|---|---|---|---|
| SciCode | 43.4% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Terminal-Bench Hard (Artificial Analysis run) | 24.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| WeirdML | 52.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 36 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.6 Luna Pro | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 144.3 | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.6 Luna Pro | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 31.3% | Not measured | Only Gemini 3.1 Flash Lite measured |
| DeepResearch Bench | 37.3% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 39 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.6 Luna Pro | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | 82.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Humanity's Last Exam (Artificial Analysis run) | 17.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| GPQA Diamond (Epoch AI run) | 81.8% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Kagi LLM Benchmark | 67.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 18 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.6 Luna Pro | Leader |
|---|---|---|---|
| OTIS Mock AIME | 80.0% | Not measured | Only Gemini 3.1 Flash Lite measured |
| FrontierMath, tiers 1 to 3 | 27.7% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 11 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.6 Luna Pro | Leader |
|---|---|---|---|
| IFBench | 77.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Long context reasoning (AA-LCR) | 74.3% | Not measured | Only Gemini 3.1 Flash Lite measured |
| DTBench | 76.8% | Not measured | Only Gemini 3.1 Flash Lite measured |
| LMCA | 35.0% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 42 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
GPT-5.6 Luna Pro costs less
Repository review
50K input + 3K output tokens
GPT-5.6 Luna Pro costs less
Agent loop
200K input + 10K output tokens
GPT-5.6 Luna Pro 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 3.1 Flash Lite | OpenAI GPT-5.6 Luna Pro |
|---|---|---|
| Maker | OpenAI | |
| Weights | No public weights listed | No public weights listed |
| Released | May 7, 2026 | July 9, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.25 | $0.20 |
| Output $/Mtok | $1.50 | $1.20 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.1 Flash Lite better than GPT-5.6 Luna Pro for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Compare them on price, context and the boards below.
Which is cheaper, Gemini 3.1 Flash Lite or GPT-5.6 Luna Pro?
Gemini 3.1 Flash Lite costs $0.25 per million input tokens and $1.50 per million output tokens; GPT-5.6 Luna Pro costs $0.20 and $1.20. Cost per solved task is known for neither of them.
Which has the bigger context window, Gemini 3.1 Flash Lite or GPT-5.6 Luna Pro?
GPT-5.6 Luna Pro, with 1.05M tokens against 1.05M.
Has any benchmark tested both Gemini 3.1 Flash Lite and GPT-5.6 Luna Pro?
No benchmark has tested both yet. Gemini 3.1 Flash Lite has results on SciCode, Terminal-Bench Hard (Artificial Analysis run) and WeirdML; GPT-5.6 Luna Pro has none yet. Compare them on price and context instead. Data as of October 22, 2026.