# Mercury 2.5 vs Sonar

> Sonar is the stronger model overall, scoring 38.5 to 33.5 on the Noometry Index. Mercury 2.5 costs 15× less per token, which makes it the better buy when Sonar's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/mercury-2-5-vs-sonar
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in math, where Sonar leads 33.7 to 23.3.
- Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $1 / $1 for Sonar.
- Mercury 2.5 accepts more context: 260K tokens versus 128K.

## Snapshot

| | Mercury 2.5 | Sonar |
|---|---|---|
| Provider | Inception | Perplexity |
| Noometry Index | 33.5 | 38.5 |
| Rank | 242 | 187 |
| Context | 260K | 128K |
| Input $/M | $0.04 | $1 |
| Output $/M | $0.15 | $1 |
| Weights | Proprietary | Proprietary |

## Coding

- Mercury 2.5: 39.5 (#156)
- Sonar: 35.7 (#221)

| Benchmark | Mercury 2.5 | Sonar |
|---|---|---|
| SciCode | 38.5% | — |
| LiveBench Coding | — | 35.1% |
| ALE-Bench | 301.65 | — |

## Reasoning

- Mercury 2.5: 22.4 (#193)
- Sonar: 21.1 (#227)

| Benchmark | Mercury 2.5 | Sonar |
|---|---|---|
| CritPt | 0% | — |
| LiveBench Reasoning | — | 46.3% |
| LiveBench Data Analysis | — | 37.9% |
| LiveBench | — | 46.9% |

## Math

- Mercury 2.5: 23.3 (#272)
- Sonar: 33.7 (#200)

| Benchmark | Mercury 2.5 | Sonar |
|---|---|---|
| ProofBench | 3% | — |
| LiveBench Math | — | 41.6% |

## Instruction Following

- Mercury 2.5: —
- Sonar: 71.4 (#150)

| Benchmark | Mercury 2.5 | Sonar |
|---|---|---|
| LiveBench Instruction Following | — | 76.2% |

## Writing & Preference

- Mercury 2.5: —
- Sonar: 52.6 (#167)

| Benchmark | Mercury 2.5 | Sonar |
|---|---|---|
| LiveBench Language | — | 44.1% |

## FAQ

### Is Mercury 2.5 better than Sonar?

Sonar is the stronger model overall, scoring 38.5 to 33.5 on the Noometry Index. Mercury 2.5 costs 15× less per token, which makes it the better buy when Sonar's lead doesn't matter for your workload.

### Which is cheaper, Mercury 2.5 or Sonar?

Mercury 2.5 is cheaper. It lists at $0.04 per million input tokens and $0.15 per million output tokens; Sonar lists at $1 and $1.

### Is Mercury 2.5 or Sonar better for coding?

Mercury 2.5 scores higher on coding benchmarks: 39.5 versus 35.7 in the Noometry coding category.

### Which has the bigger context window?

Mercury 2.5 does, with 260K tokens against 128K.

### How many benchmarks do Mercury 2.5 and Sonar share?

0 benchmarks have published results for both models. Mercury 2.5 has 4 scored results on Noometry and Sonar has 7.