Model comparison
Mercury vs o3-pro
o3-pro is the stronger model overall, scoring 42.9 to 37.6 on the Noometry Index.
Last verified . 1 shared benchmarks.
Summary
- They share 1 benchmark with published results for both. Mercury scores higher in 0 categories and o3-pro in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in long context, where o3-pro leads 72.2 to 38.4.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 21.6% for Mercury and 72.1% for o3-pro.
Side by side
| Mercury | o3-pro | |
|---|---|---|
| Provider | Inception | OpenAI |
| Noometry Index | 37.6 | 42.9 |
| Released | — | 2025-06-10 |
| Weights | Proprietary | Proprietary |
| Context window | — | 200K |
| Max output | — | 100K |
| Input $ / M tokens | — | $20 |
| Output $ / M tokens | — | $80 |
| Results tracked | 9 | 12 |
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Category by category
Coding o3-pro leads
Mercury: 38.7 (#170), o3-pro: 55.5 (#24)
| Benchmark | Mercury | o3-pro |
|---|---|---|
| Aider Polyglot | — | 84.9% |
| WeirdML | — | 58.2% |
| LMArena Coding | 1322 | — |
Reasoning o3-pro leads
Mercury: 17.5 (#293), o3-pro: 23.8 (#171)
| Benchmark | Mercury | o3-pro |
|---|---|---|
| Kagi LLM Benchmark | 21.6% | 72.1% |
| ARC-AGI-2 | — | 4.9% |
| ARC-AGI-1 | — | 59.3% |
| LMArena Hard Prompts | 1285 | — |
| DTBench | — | 86.9% |
| LMCA | — | 38.5% |
| Epoch Capabilities Index | — | 147.42 |
Knowledge Not comparable
Mercury: —, o3-pro: 29.5 (#238)
| Benchmark | Mercury | o3-pro |
|---|---|---|
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |
Multilingual Not comparable
Mercury: 41.6 (#206), o3-pro: —
| Benchmark | Mercury | o3-pro |
|---|---|---|
| LMArena Non-English | 1260 | — |
Instruction Following Not comparable
Mercury: 65.2 (#224), o3-pro: —
| Benchmark | Mercury | o3-pro |
|---|---|---|
| LMArena Instruction Following | 1239 | — |
Long Context o3-pro leads
Mercury: 38.4 (#198), o3-pro: 72.2 (#1)
| Benchmark | Mercury | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
| LMArena Longer Query | 1266 | — |
Writing & Preference o3-pro leads
Mercury: 46.2 (#221), o3-pro: 57.1 (#133)
| Benchmark | Mercury | o3-pro |
|---|---|---|
| LMArena Text | 1282 | — |
| LMArena Creative Writing | 1191 | — |
| Short-Story Creative Writing | — | 84.4% |
| LMArena Multi-Turn | 1282 | — |
Frequently asked questions
Is Mercury better than o3-pro?
o3-pro is the stronger model overall, scoring 42.9 to 37.6 on the Noometry Index.
Is Mercury or o3-pro better for coding?
o3-pro scores higher on coding benchmarks: 55.5 versus 38.7 in the Noometry coding category.
How many benchmarks do Mercury and o3-pro share?
1 benchmark has published results for both models. Mercury has 9 scored results on Noometry and o3-pro has 12.