Model comparison
GPT-5.2 Pro vs Mercury 2
GPT-5.2 Pro is the stronger model overall, scoring 52.3 to 39.1 on the Noometry Index. Mercury 2 costs 154× less per token, which makes it the better buy when GPT-5.2 Pro's lead doesn't matter for your workload.
Last verified . 0 shared benchmarks.
Summary
- The widest gap is in reasoning, where GPT-5.2 Pro leads 51.5 to 23.8.
- Mercury 2 is cheaper at $0.25 / $0.75 per million input/output tokens, against $21 / $168 for GPT-5.2 Pro.
- GPT-5.2 Pro accepts more context: 400K tokens versus 128K.
Side by side
| GPT-5.2 Pro | Mercury 2 | |
|---|---|---|
| Provider | OpenAI | Inception |
| Noometry Index | 52.3 | 39.1 |
| Released | 2025-12-11 | 2026-02-20 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | 128K |
| Max output | 128K | 50K |
| Input $ / M tokens | $21 | $0.25 |
| Output $ / M tokens | $168 | $0.75 |
| Results tracked | 8 | 17 |
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Category by category
Coding Not comparable
GPT-5.2 Pro: —, Mercury 2: 33.5 (#255)
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| LMArena WebDev | — | 1171 |
| SciCode | — | 38.7% |
| WeirdML | — | 43.2% |
| LMArena Coding | — | 1391 |
| ALE-Bench | — | 785.58 |
Reasoning GPT-5.2 Pro leads
GPT-5.2 Pro: 51.5 (#33), Mercury 2: 23.8 (#170)
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| ARC-AGI-2 | 54.2% | — |
| SimpleBench | 57.4% | — |
| NYT Connections (extended) | 79.3% | — |
| ARC-AGI-1 | 90.5% | — |
| CritPt | — | 0.8% |
| LMArena Hard Prompts | — | 1362 |
| Epoch Capabilities Index | 155.4 | — |
Math Not comparable
GPT-5.2 Pro: 65.3 (#29), Mercury 2: —
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 74% | — |
| FrontierMath Tier 4 | 46% | — |
| FrontierMath Tier 4 (v1) | 31.3% | — |
Knowledge Not comparable
GPT-5.2 Pro: —, Mercury 2: 36.2 (#172)
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| Vectara Hallucination Rate | — | 12.3% |
| LMArena Expert | — | 1358 |
Multilingual Not comparable
GPT-5.2 Pro: —, Mercury 2: 46.6 (#157)
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| LMArena Non-English | — | 1331 |
| LMArena Chinese | — | 1417 |
| LMArena Russian | — | 1304 |
Instruction Following Not comparable
GPT-5.2 Pro: —, Mercury 2: 70.2 (#165)
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | — | 1329 |
Long Context Not comparable
GPT-5.2 Pro: —, Mercury 2: 40.5 (#154)
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| LMArena Longer Query | — | 1330 |
Writing & Preference Not comparable
GPT-5.2 Pro: —, Mercury 2: 53.8 (#155)
| Benchmark | GPT-5.2 Pro | Mercury 2 |
|---|---|---|
| LMArena Text | — | 1355 |
| LMArena Creative Writing | — | 1289 |
| LMArena Multi-Turn | — | 1358 |
Frequently asked questions
Is GPT-5.2 Pro better than Mercury 2?
GPT-5.2 Pro is the stronger model overall, scoring 52.3 to 39.1 on the Noometry Index. Mercury 2 costs 154× less per token, which makes it the better buy when GPT-5.2 Pro's lead doesn't matter for your workload.
Which is cheaper, GPT-5.2 Pro or Mercury 2?
Mercury 2 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; GPT-5.2 Pro lists at $21 and $168.
Which has the bigger context window?
GPT-5.2 Pro does, with 400K tokens against 128K.
How many benchmarks do GPT-5.2 Pro and Mercury 2 share?
0 benchmarks have published results for both models. GPT-5.2 Pro has 8 scored results on Noometry and Mercury 2 has 17.