Model comparison
Claude Opus 5.5 vs Phi-4
Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 31.2 on the Noometry Index. Phi-4 costs 91× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.
Last verified . 17 shared benchmarks.
MicrosoftSummary
- They share 17 benchmarks with published results for both. Claude Opus 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 Opus 5.5 leads 91.8 to 20.8.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Opus 5.5 and 13.8% for Phi-4.
- Phi-4 is cheaper at $0.07 / $0.14 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
- Claude Opus 5.5 accepts more context: 1M tokens versus 128K.
- Phi-4 has downloadable open weights; the other is API-only.
Side by side
| Claude Opus 5.5 | Phi-4 | |
|---|---|---|
| Provider | Anthropic | Microsoft |
| Noometry Index | 68.6 | 31.2 |
| Released | 2026-09-22 | 2024-12-11 |
| Weights | Proprietary | Open |
| Context window | 1M | 128K |
| Max output | 128K | 4K |
| Input $ / M tokens | $4 | $0.07 |
| Output $ / M tokens | $20 | $0.14 |
| Results tracked | 44 | 37 |
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Category by category
Coding Claude Opus 5.5 leads
Claude Opus 5.5: 71.9 (#3), Phi-4: 34.4 (#239)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| LMArena Coding | 1547 | 1231 |
| FrontierCode | 54.6% | — |
| CursorBench | 57.8% | — |
| LMArena WebDev | 1813 | — |
| FrontierSWE | 62.3% | — |
| SciCode | 66.9% | — |
| BigCodeBench Instruct | — | 45.5% |
| LiveBench Coding | — | 30.7% |
| MirrorCode | 77.4% | — |
| BigCodeBench Complete | — | 55.4% |
| ALE-Bench | 2,147 | — |
Agentic & Tool Use Claude Opus 5.5 leads
Claude Opus 5.5: 45.3 (#15), Phi-4: 22.8 (#128)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| APEX-Agents | 73.5% | — |
| Berkeley Function Calling Leaderboard | — | 28.8% |
| BALROG | — | 11.6% |
| GDP.pdf | 30.6% | — |
| Vending-Bench 2 | 9,235 | — |
Reasoning Claude Opus 5.5 leads
Claude Opus 5.5: 80.2 (#3), Phi-4: 17.7 (#291)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| LMArena Hard Prompts | 1535 | 1220 |
| Epoch Capabilities Index | 167.33 | 130.42 |
| ARC-AGI-2 | 93.3% | — |
| NYT Connections (extended) | 88.5% | — |
| ARC-AGI-1 | 98.5% | — |
| CritPt | 31.7% | — |
| Chess Puzzles | — | 1% |
| EBR-Bench | 71.4% | — |
| LiveBench Reasoning | — | 47.8% |
| Mystery Game Puzzles | 71% | — |
| DTBench | 98.9% | — |
| LiveBench Data Analysis | — | 45.2% |
| LMCA | 68.2% | — |
| LiveBench | — | 41.6% |
Math Claude Opus 5.5 leads
Claude Opus 5.5: 91.8 (#3), Phi-4: 20.8 (#285)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 13.8% |
| LMArena Math | 1506 | 1246 |
| FrontierMath (Tiers 1-3) | 91.2% | — |
| FrontierMath Tier 4 | 95% | — |
| ProofBench | 100% | — |
| LiveBench Math | — | 42% |
| MATH Level 5 | — | 64.9% |
| FrontierMath Erdős | 2.9% | — |
Knowledge Claude Opus 5.5 leads
Claude Opus 5.5: 66.4 (#10), Phi-4: 32.6 (#209)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| GPQA Diamond | 90.6% | 56.1% |
| LMArena Expert | 1547 | 1203 |
| SimpleQA Verified | 72.2% | — |
| Confabulations | — | 29.4% |
| Vectara Hallucination Rate | — | 3.7% |
| MMLU | — | 84.8% |
Multimodal Not comparable
Claude Opus 5.5: 57.8 (#1), Phi-4: —
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| LMArena Vision | 1321 | — |
| Blueprint-Bench 2 | 51.2% | — |
| Furniture Assembly | 83.3% | — |
Multilingual Claude Opus 5.5 leads
Claude Opus 5.5: 59.1 (#2), Phi-4: 37.2 (#237)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| LMArena Non-English | 1507 | 1197 |
| LMArena Chinese | 1588 | 1212 |
| LMArena French | 1514 | 1224 |
| LMArena Russian | 1520 | 1209 |
| LMArena Spanish | 1507 | 1234 |
| LMArena German | — | 1222 |
| LMArena Japanese | — | 1158 |
| LMArena Korean | — | 1151 |
Instruction Following Claude Opus 5.5 leads
Claude Opus 5.5: 80.0 (#3), Phi-4: 60.4 (#251)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| LMArena Instruction Following | 1537 | 1201 |
| LiveBench Instruction Following | — | 58.4% |
Long Context Claude Opus 5.5 leads
Claude Opus 5.5: 47.1 (#19), Phi-4: 36.9 (#226)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| LMArena Longer Query | 1532 | 1217 |
Writing & Preference Claude Opus 5.5 leads
Claude Opus 5.5: 78.2 (#3), Phi-4: 40.5 (#244)
| Benchmark | Claude Opus 5.5 | Phi-4 |
|---|---|---|
| LMArena Text | 1515 | 1217 |
| LMArena Creative Writing | 1533 | 1182 |
| LMArena Multi-Turn | 1499 | 1206 |
| Short-Story Creative Writing | — | 62.6% |
| EQ-Bench Creative Writing | 2050 | — |
| LiveBench Language | — | 25.6% |
Frequently asked questions
Is Claude Opus 5.5 better than Phi-4?
Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 31.2 on the Noometry Index. Phi-4 costs 91× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 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 Opus 5.5 lists at $4 and $20.
Is Claude Opus 5.5 or Phi-4 better for coding?
Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 34.4 in the Noometry coding category.
Which has the bigger context window?
Claude Opus 5.5 does, with 1M tokens against 128K.
How many benchmarks do Claude Opus 5.5 and Phi-4 share?
17 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Phi-4 has 37.