Model comparison
GPT-5 Pro vs Mercury 2.5
GPT-5 Pro is the stronger model overall, scoring 46.4 to 33.5 on the Noometry Index. Mercury 2.5 costs 611× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.
Last verified . 0 shared benchmarks.
Summary
- The widest gap is in math, where GPT-5 Pro leads 48.5 to 23.3.
- Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
- GPT-5 Pro accepts more context: 400K tokens versus 260K.
Side by side
| GPT-5 Pro | Mercury 2.5 | |
|---|---|---|
| Provider | OpenAI | Inception |
| Noometry Index | 46.4 | 33.5 |
| Released | 2025-10-06 | 2026-09-08 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | 260K |
| Max output | 272K | 66K |
| Input $ / M tokens | $15 | $0.04 |
| Output $ / M tokens | $120 | $0.15 |
| Results tracked | 12 | 4 |
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Category by category
Coding GPT-5 Pro leads
GPT-5 Pro: 44.0 (#80), Mercury 2.5: 39.5 (#156)
| Benchmark | GPT-5 Pro | Mercury 2.5 |
|---|---|---|
| SciCode | — | 38.5% |
| WeirdML | 60.4% | — |
| ALE-Bench | — | 301.65 |
| AlgoTune | 1.31 | — |
Reasoning GPT-5 Pro leads
GPT-5 Pro: 38.9 (#62), Mercury 2.5: 22.4 (#193)
| Benchmark | GPT-5 Pro | Mercury 2.5 |
|---|---|---|
| ARC-AGI-2 | 18.3% | — |
| SimpleBench | 61.6% | — |
| Kagi LLM Benchmark | 76.8% | — |
| ARC-AGI-1 | 70.2% | — |
| CritPt | — | 0% |
| EnigmaEval | 18.8% | — |
| Epoch Capabilities Index | 150.28 | — |
Math GPT-5 Pro leads
GPT-5 Pro: 48.5 (#63), Mercury 2.5: 23.3 (#272)
| Benchmark | GPT-5 Pro | Mercury 2.5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 55.8% | — |
| FrontierMath Tier 4 | 19.5% | — |
| ProofBench | — | 3% |
| FrontierMath Tier 4 (v1) | 14.6% | — |
Knowledge Not comparable
GPT-5 Pro: 56.7 (#42), Mercury 2.5: —
| Benchmark | GPT-5 Pro | Mercury 2.5 |
|---|---|---|
| Humanity's Last Exam | 31.6% | — |
Frequently asked questions
Is GPT-5 Pro better than Mercury 2.5?
GPT-5 Pro is the stronger model overall, scoring 46.4 to 33.5 on the Noometry Index. Mercury 2.5 costs 611× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.
Which is cheaper, GPT-5 Pro or Mercury 2.5?
Mercury 2.5 is cheaper. It lists at $0.04 per million input tokens and $0.15 per million output tokens; GPT-5 Pro lists at $15 and $120.
Is GPT-5 Pro or Mercury 2.5 better for coding?
GPT-5 Pro scores higher on coding benchmarks: 44.0 versus 39.5 in the Noometry coding category.
Which has the bigger context window?
GPT-5 Pro does, with 400K tokens against 260K.
How many benchmarks do GPT-5 Pro and Mercury 2.5 share?
0 benchmarks have published results for both models. GPT-5 Pro has 12 scored results on Noometry and Mercury 2.5 has 4.