Compare / Phi 4 vs GPT-5.6 Luna
Phi 4 vs GPT-5.6 Luna
Which is cheaper, which is more capable, and which does better at each kind of work, from 13 results on 3 sources that measured both models.
Phi 4 or GPT-5.6 Luna? The short answer
- Phi 4 is cheaper: $0.088 against $0.45 per million tokens, 5.1 times less.
- GPT-5.6 Luna scores higher on the Artificial Analysis Intelligence Index: 37.3 against 5.9.
- On our business benchmarks, Phi 4 ranks higher for sticking to the facts.
- On our business benchmarks, GPT-5.6 Luna ranks higher for agents and tool use, reasoning and knowledge and writing.
At a glance
| Phi 4 | GPT-5.6 Luna | |
|---|---|---|
| Price per million tokens | $0.070 in · $0.14 out | $0.20 in · $1.20 out |
| Blended (3 in : 1 out) | $0.088 | $0.45 |
| Cheapest host, blended | – | $0.23 (OpenAI) |
| Intelligence Index | 5.9 | 37.3 |
| Spring Prompt overall | – | – |
| Output speed, tokens a second | 42 | – |
| Context window | 16,384 tokens | 1,050,000 tokens |
| Weights | Open | 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 | Phi 4 | GPT-5.6 Luna |
|---|---|---|
| Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls | 122 of 161 | 47 of 161 |
| Professional workReal tasks from banking, consulting and law, business documents and freelance projects | not measured | 20 of 51 |
| Reasoning and knowledgeHard questions across science, maths and general knowledge | 178 of 195 | 38 of 195 |
| WritingWhat people prefer in blind comparisons, and judged writing quality | 175 of 187 | 57 of 187 |
| Sticking to the factsSummarising without inventing things, and factual answers | 3 of 153 | 59 of 153 |
Every shared result
| Benchmark | Metric | Phi 4 | GPT-5.6 Luna |
|---|---|---|---|
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,256 | 1,463 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,210 | 1,412 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,268 | 1,491 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,245 | 1,446 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,256 | 1,454 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,229 | 1,435 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 5.90 | 37.3 |
| Artificial Analysisreported | GPQA Diamond% of questions | 57.5% | 91.1% |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 3.8% | 39.5% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 0.0% | 83.7% |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 19.0% | 15.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.34 | 0.38 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 25.7 | 53.7 |
Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.
Quick answers
Is Phi 4 better than GPT-5.6 Luna?
It depends on the task. Among models available today, on our benchmarks and licensed sources, Phi 4 ranks higher for sticking to the facts; GPT-5.6 Luna ranks higher for agents and tool use, reasoning and knowledge and writing.
Which is cheaper, Phi 4 or GPT-5.6 Luna?
Phi 4 costs $0.088 per million tokens (three input to one output), against $0.45 for GPT-5.6 Luna.
Run Phi 4 and GPT-5.6 Luna on your own prompt
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