Model comparison
Claude Haiku 5.5 vs Mercury 2.5
Claude Haiku 5.5 is the stronger model overall, scoring 49.5 to 33.5 on the Noometry Index. Mercury 2.5 costs 3.0× less per token, which makes it the better buy when Claude Haiku 5.5's lead doesn't matter for your workload.
Last verified . 0 shared benchmarks.
Summary
- The widest gap is in math, where Claude Haiku 5.5 leads 73.6 to 23.3.
- Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $0.10 / $0.50 for Claude Haiku 5.5.
- Claude Haiku 5.5 accepts more context: 1M tokens versus 260K.
Side by side
| Claude Haiku 5.5 | Mercury 2.5 | |
|---|---|---|
| Provider | Anthropic | Inception |
| Noometry Index | 49.5 | 33.5 |
| Released | 2026-10-07 | 2026-09-08 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 260K |
| Max output | 128K | 66K |
| Input $ / M tokens | $0.10 | $0.04 |
| Output $ / M tokens | $0.50 | $0.15 |
| Results tracked | 9 | 4 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Claude Haiku 5.5 leads
Claude Haiku 5.5: 49.2 (#50), Mercury 2.5: 39.5 (#156)
| Benchmark | Claude Haiku 5.5 | Mercury 2.5 |
|---|---|---|
| LMArena WebDev | 1587 | — |
| SciCode | — | 38.5% |
| ALE-Bench | — | 301.65 |
Reasoning Claude Haiku 5.5 leads
Claude Haiku 5.5: 35.2 (#69), Mercury 2.5: 22.4 (#193)
| Benchmark | Claude Haiku 5.5 | Mercury 2.5 |
|---|---|---|
| NYT Connections (extended) | 65.7% | — |
| CritPt | — | 0% |
| Mystery Game Puzzles | 30% | — |
Math Claude Haiku 5.5 leads
Claude Haiku 5.5: 73.6 (#18), Mercury 2.5: 23.3 (#272)
| Benchmark | Claude Haiku 5.5 | Mercury 2.5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 75.1% | — |
| FrontierMath Tier 4 | 46.3% | — |
| OTIS Mock AIME 2024-2025 | 98.9% | — |
| ProofBench | — | 3% |
Knowledge Not comparable
Claude Haiku 5.5: 50.8 (#70), Mercury 2.5: —
| Benchmark | Claude Haiku 5.5 | Mercury 2.5 |
|---|---|---|
| GPQA Diamond | 89.6% | — |
| SimpleQA Verified | 23.8% | — |
Multimodal Not comparable
Claude Haiku 5.5: 43.7 (#21), Mercury 2.5: —
| Benchmark | Claude Haiku 5.5 | Mercury 2.5 |
|---|---|---|
| Furniture Assembly | 47.5% | — |
Frequently asked questions
Is Claude Haiku 5.5 better than Mercury 2.5?
Claude Haiku 5.5 is the stronger model overall, scoring 49.5 to 33.5 on the Noometry Index. Mercury 2.5 costs 3.0× less per token, which makes it the better buy when Claude Haiku 5.5's lead doesn't matter for your workload.
Which is cheaper, Claude Haiku 5.5 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; Claude Haiku 5.5 lists at $0.10 and $0.50.
Is Claude Haiku 5.5 or Mercury 2.5 better for coding?
Claude Haiku 5.5 scores higher on coding benchmarks: 49.2 versus 39.5 in the Noometry coding category.
Which has the bigger context window?
Claude Haiku 5.5 does, with 1M tokens against 260K.
How many benchmarks do Claude Haiku 5.5 and Mercury 2.5 share?
0 benchmarks have published results for both models. Claude Haiku 5.5 has 9 scored results on Noometry and Mercury 2.5 has 4.