Model comparison
Mercury 2 vs o3-mini
Mercury 2 is the stronger model overall, scoring 39.1 to 36.7 on the Noometry Index.
Last verified . 14 shared benchmarks.
Summary
- They share 14 benchmarks with published results for both. Mercury 2 scores higher in 4 categories and o3-mini in 3 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Mercury 2 leads 23.8 to 16.3.
- Mercury 2 is cheaper at $0.25 / $0.75 per million input/output tokens, against $1.10 / $4.40 for o3-mini.
- o3-mini accepts more context: 200K tokens versus 128K.
Side by side
| Mercury 2 | o3-mini | |
|---|---|---|
| Provider | Inception | OpenAI |
| Noometry Index | 39.1 | 36.7 |
| Released | 2026-02-20 | 2024-12-20 |
| Weights | Proprietary | Proprietary |
| Context window | 128K | 200K |
| Max output | 50K | 100K |
| Input $ / M tokens | $0.25 | $1.10 |
| Output $ / M tokens | $0.75 | $4.40 |
| Results tracked | 17 | 51 |
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Category by category
Coding o3-mini leads
Mercury 2: 33.5 (#255), o3-mini: 40.8 (#132)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| SciCode | 38.7% | 39.8% |
| WeirdML | 43.2% | 43.7% |
| LMArena Coding | 1391 | 1378 |
| Aider Polyglot | — | 60.4% |
| LMArena WebDev | 1171 | — |
| GSO | — | 1.3% |
| LiveBench Coding | — | 82.7% |
| CadEval | — | 54% |
| ALE-Bench | 785.58 | — |
Agentic & Tool Use Not comparable
Mercury 2: —, o3-mini: 29.6 (#84)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| Cybench | — | 22.5% |
Reasoning Mercury 2 leads
Mercury 2: 23.8 (#170), o3-mini: 16.3 (#305)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| CritPt | 0.8% | 0.3% |
| LMArena Hard Prompts | 1362 | 1366 |
| ARC-AGI-2 | — | 3% |
| SimpleBench | — | 22.8% |
| ARC-AGI-1 | — | 34.5% |
| Chess Puzzles | — | 17% |
| LiveBench Reasoning | — | 89.6% |
| Mystery Game Puzzles | — | 7% |
| DTBench | — | 68.8% |
| LiveBench Data Analysis | — | 70.6% |
| LMCA | — | 19% |
| Epoch Capabilities Index | — | 140.34 |
| ForecastBench | — | 59.6 |
| LiveBench | — | 75.9% |
Math Not comparable
Mercury 2: —, o3-mini: 28.1 (#244)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 18.6% |
| FrontierMath Tier 4 | — | 0% |
| OTIS Mock AIME 2024-2025 | — | 76.9% |
| LiveBench Math | — | 77.3% |
| LMArena Math | — | 1396 |
| MATH Level 5 | — | 96.5% |
| FrontierMath (Feb 2025 set) | — | 12.4% |
| FrontierMath Tier 4 (v1) | — | 4.2% |
Knowledge o3-mini leads
Mercury 2: 36.2 (#172), o3-mini: 38.3 (#146)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| LMArena Expert | 1358 | 1364 |
| GPQA Diamond | — | 77% |
| SimpleQA Verified | — | 15.3% |
| Confabulations | — | 17.9% |
| Vectara Hallucination Rate | 12.3% | — |
Multilingual Too close to call
Mercury 2: 46.6 (#157), o3-mini: 45.7 (#164)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| LMArena Non-English | 1331 | 1319 |
| LMArena Chinese | 1417 | 1379 |
| LMArena Russian | 1304 | 1304 |
| LMArena French | — | 1334 |
| LMArena German | — | 1303 |
| LMArena Japanese | — | 1286 |
| LMArena Korean | — | 1314 |
| LMArena Spanish | — | 1321 |
Instruction Following o3-mini leads
Mercury 2: 70.2 (#165), o3-mini: 75.1 (#72)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| LMArena Instruction Following | 1329 | 1337 |
| LiveBench Instruction Following | — | 84.4% |
Long Context Mercury 2 leads
Mercury 2: 40.5 (#154), o3-mini: 33.8 (#256)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| LMArena Longer Query | 1330 | 1343 |
| Fiction.LiveBench | — | 50% |
Writing & Preference Mercury 2 leads
Mercury 2: 53.8 (#155), o3-mini: 50.3 (#182)
| Benchmark | Mercury 2 | o3-mini |
|---|---|---|
| LMArena Text | 1355 | 1337 |
| LMArena Creative Writing | 1289 | 1286 |
| LMArena Multi-Turn | 1358 | 1320 |
| Short-Story Creative Writing | — | 61.7% |
| LiveBench Language | — | 50.7% |
Frequently asked questions
Is Mercury 2 better than o3-mini?
Mercury 2 is the stronger model overall, scoring 39.1 to 36.7 on the Noometry Index.
Which is cheaper, Mercury 2 or o3-mini?
Mercury 2 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; o3-mini lists at $1.10 and $4.40.
Is Mercury 2 or o3-mini better for coding?
o3-mini scores higher on coding benchmarks: 40.8 versus 33.5 in the Noometry coding category.
Which has the bigger context window?
o3-mini does, with 200K tokens against 128K.
How many benchmarks do Mercury 2 and o3-mini share?
14 benchmarks have published results for both models. Mercury 2 has 17 scored results on Noometry and o3-mini has 51.