Model comparison
Claude Opus 4 vs Mercury 2
Claude Opus 4 is the stronger model overall, scoring 43.1 to 39.1 on the Noometry Index. Mercury 2 costs 80× less per token, which makes it the better buy when Claude Opus 4's lead doesn't matter for your workload.
Last verified . 14 shared benchmarks.
Summary
- They share 14 benchmarks with published results for both. Claude Opus 4 scores higher in 6 categories and Mercury 2 in 1 category; 6 gaps are clear of the uncertainty.
- The widest gap is in coding, where Claude Opus 4 leads 47.2 to 33.5.
- Mercury 2 is cheaper at $0.25 / $0.75 per million input/output tokens, against $15 / $75 for Claude Opus 4.
- Claude Opus 4 accepts more context: 200K tokens versus 128K.
Side by side
| Claude Opus 4 | Mercury 2 | |
|---|---|---|
| Provider | Anthropic | Inception |
| Noometry Index | 43.1 | 39.1 |
| Released | 2025-05-22 | 2026-02-20 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 128K |
| Max output | 32K | 50K |
| Input $ / M tokens | $15 | $0.25 |
| Output $ / M tokens | $75 | $0.75 |
| Results tracked | 56 | 17 |
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Category by category
Coding Claude Opus 4 leads
Claude Opus 4: 47.2 (#62), Mercury 2: 33.5 (#255)
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| WeirdML | 43.7% | 43.2% |
| LMArena Coding | 1442 | 1391 |
| SWE-bench Verified | 70.7% | — |
| SWE-bench Verified (bash only) | 67.6% | — |
| Aider Polyglot | 72% | — |
| LMArena WebDev | — | 1171 |
| SciCode | — | 38.7% |
| GSO | 6.9% | — |
| ALE-Bench | — | 785.58 |
| AlgoTune | 1.33 | — |
Agentic & Tool Use Not comparable
Claude Opus 4: 34.8 (#42), Mercury 2: —
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| Cybench | 38% | — |
| DeepResearch Bench | 46.8% | — |
| LMArena Search | 1127 | — |
| METR Time Horizons | 63.9% | — |
Reasoning Claude Opus 4 leads
Claude Opus 4: 27.3 (#121), Mercury 2: 23.8 (#170)
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| CritPt | 0.3% | 0.8% |
| LMArena Hard Prompts | 1399 | 1362 |
| ARC-AGI-2 | 8.6% | — |
| SimpleBench | 58.8% | — |
| Kagi LLM Benchmark | 74.3% | — |
| ARC-AGI-1 | 35.7% | — |
| EnigmaEval | 5.6% | — |
| DTBench | 81.6% | — |
| LMCA | 37.4% | — |
| Epoch Capabilities Index | 142.67 | — |
| ForecastBench | 61.1 | — |
Math Not comparable
Claude Opus 4: 42.0 (#86), Mercury 2: —
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 64.4% | — |
| Omni-MATH | 61.6% | — |
| LMArena Math | 1390 | — |
| MATH Level 5 | 85% | — |
| FrontierMath (Feb 2025 set) | 4.5% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Claude Opus 4 leads
Claude Opus 4: 44.0 (#88), Mercury 2: 36.2 (#172)
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| Vectara Hallucination Rate | 12% | 12.3% |
| LMArena Expert | 1386 | 1358 |
| GPQA Diamond | 76.3% | — |
| Humanity's Last Exam | 10.7% | — |
| MMLU-Pro | 87.5% | — |
| Confabulations | 15.9% | — |
| GPQA (HELM) | 70.8% | — |
Multimodal Not comparable
Claude Opus 4: 31.5 (#106), Mercury 2: —
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| LMArena Vision | 1192 | — |
| GeoBench | 49% | — |
| VPCT | 38% | — |
Multilingual Claude Opus 4 leads
Claude Opus 4: 48.8 (#138), Mercury 2: 46.6 (#157)
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| LMArena Non-English | 1362 | 1331 |
| LMArena Chinese | 1386 | 1417 |
| LMArena Russian | 1392 | 1304 |
| LMArena French | 1372 | — |
| LMArena German | 1391 | — |
| LMArena Japanese | 1331 | — |
| LMArena Korean | 1321 | — |
| LMArena Spanish | 1389 | — |
Instruction Following Claude Opus 4 leads
Claude Opus 4: 77.1 (#28), Mercury 2: 70.2 (#165)
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | 1406 | 1329 |
| IFEval | 91.8% | — |
Long Context Too close to call
Claude Opus 4: 39.6 (#172), Mercury 2: 40.5 (#154)
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| LMArena Longer Query | 1422 | 1330 |
| Fiction.LiveBench | 61.1% | — |
Writing & Preference Claude Opus 4 leads
Claude Opus 4: 61.2 (#89), Mercury 2: 53.8 (#155)
| Benchmark | Claude Opus 4 | Mercury 2 |
|---|---|---|
| LMArena Text | 1377 | 1355 |
| LMArena Creative Writing | 1387 | 1289 |
| LMArena Multi-Turn | 1396 | 1358 |
| Short-Story Creative Writing | 83.6% | — |
| EQ-Bench Creative Writing | 1580 | — |
| WildBench | 85.2% | — |
Frequently asked questions
Is Claude Opus 4 better than Mercury 2?
Claude Opus 4 is the stronger model overall, scoring 43.1 to 39.1 on the Noometry Index. Mercury 2 costs 80× less per token, which makes it the better buy when Claude Opus 4's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 4 or Mercury 2?
Mercury 2 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; Claude Opus 4 lists at $15 and $75.
Is Claude Opus 4 or Mercury 2 better for coding?
Claude Opus 4 scores higher on coding benchmarks: 47.2 versus 33.5 in the Noometry coding category.
Which has the bigger context window?
Claude Opus 4 does, with 200K tokens against 128K.
How many benchmarks do Claude Opus 4 and Mercury 2 share?
14 benchmarks have published results for both models. Claude Opus 4 has 56 scored results on Noometry and Mercury 2 has 17.