Model comparison
Claude Sonnet 5.5 vs Phi-4
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 31.2 on the Noometry Index. Phi-4 costs 46× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.
Last verified . 15 shared benchmarks.
MicrosoftSummary
- They share 15 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 9 categories and Phi-4 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 20.8.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Sonnet 5.5 and 13.8% for Phi-4.
- Phi-4 is cheaper at $0.07 / $0.14 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
- Claude Sonnet 5.5 accepts more context: 1M tokens versus 128K.
- Phi-4 has downloadable open weights; the other is API-only.
Side by side
| Claude Sonnet 5.5 | Phi-4 | |
|---|---|---|
| Provider | Anthropic | Microsoft |
| Noometry Index | 61.9 | 31.2 |
| Released | 2026-09-28 | 2024-12-11 |
| Weights | Proprietary | Open |
| Context window | 1M | 128K |
| Max output | 128K | 4K |
| Input $ / M tokens | $2 | $0.07 |
| Output $ / M tokens | $10 | $0.14 |
| Results tracked | 32 | 37 |
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Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 67.3 (#6), Phi-4: 34.4 (#239)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| LMArena Coding | 1513 | 1231 |
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1774 | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| BigCodeBench Instruct | — | 45.5% |
| LiveBench Coding | — | 30.7% |
| BigCodeBench Complete | — | 55.4% |
| ALE-Bench | 1,819 | — |
Agentic & Tool Use Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 45.0 (#16), Phi-4: 22.8 (#128)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| APEX-Agents | 75.5% | — |
| Berkeley Function Calling Leaderboard | — | 28.8% |
| BALROG | — | 11.6% |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 54.0 (#28), Phi-4: 17.7 (#291)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| LMArena Hard Prompts | 1495 | 1220 |
| Epoch Capabilities Index | 165.03 | 130.42 |
| NYT Connections (extended) | 80.5% | — |
| CritPt | 31.4% | — |
| Chess Puzzles | — | 1% |
| LiveBench Reasoning | — | 47.8% |
| Mystery Game Puzzles | 65% | — |
| LiveBench Data Analysis | — | 45.2% |
| LiveBench | — | 41.6% |
Math Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 87.9 (#6), Phi-4: 20.8 (#285)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 13.8% |
| LMArena Math | 1510 | 1246 |
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| ProofBench | 100% | — |
| LiveBench Math | — | 42% |
| MATH Level 5 | — | 64.9% |
| FrontierMath Erdős | 2.9% | — |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#12), Phi-4: 32.6 (#209)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| GPQA Diamond | 95.6% | 56.1% |
| LMArena Expert | 1540 | 1203 |
| SimpleQA Verified | 46.5% | — |
| Confabulations | — | 29.4% |
| Vectara Hallucination Rate | — | 3.7% |
| MMLU | — | 84.8% |
Multimodal Not comparable
Claude Sonnet 5.5: 51.5 (#6), Phi-4: —
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| LMArena Vision | 1289 | — |
| Furniture Assembly | 75% | — |
Multilingual Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 55.3 (#30), Phi-4: 37.2 (#237)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| LMArena Non-English | 1452 | 1197 |
| LMArena Chinese | 1522 | 1212 |
| LMArena Russian | 1451 | 1209 |
| LMArena French | — | 1224 |
| LMArena German | — | 1222 |
| LMArena Japanese | — | 1158 |
| LMArena Korean | — | 1151 |
| LMArena Spanish | — | 1234 |
Instruction Following Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 78.3 (#11), Phi-4: 60.4 (#251)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| LMArena Instruction Following | 1495 | 1201 |
| LiveBench Instruction Following | — | 58.4% |
Long Context Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 45.9 (#28), Phi-4: 36.9 (#226)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| LMArena Longer Query | 1498 | 1217 |
Writing & Preference Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#40), Phi-4: 40.5 (#244)
| Benchmark | Claude Sonnet 5.5 | Phi-4 |
|---|---|---|
| LMArena Text | 1471 | 1217 |
| LMArena Creative Writing | 1465 | 1182 |
| LMArena Multi-Turn | 1474 | 1206 |
| Short-Story Creative Writing | — | 62.6% |
| LiveBench Language | — | 25.6% |
Frequently asked questions
Is Claude Sonnet 5.5 better than Phi-4?
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 31.2 on the Noometry Index. Phi-4 costs 46× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.
Which is cheaper, Claude Sonnet 5.5 or Phi-4?
Phi-4 is cheaper. It lists at $0.07 per million input tokens and $0.14 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.
Is Claude Sonnet 5.5 or Phi-4 better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 34.4 in the Noometry coding category.
Which has the bigger context window?
Claude Sonnet 5.5 does, with 1M tokens against 128K.
How many benchmarks do Claude Sonnet 5.5 and Phi-4 share?
15 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Phi-4 has 37.