Noometry

Model comparison

Claude Opus 5 vs Mercury 2.5

Claude Opus 5 has enough public results to be ranked (#4); Mercury 2.5 does not yet, so treat this comparison as directional.

Last verified . 2 shared benchmarks.

Claude Opus 5 Anthropic

67.7

Rank #4 Confirmed

Mercury 2.5 Inception

30.2

Unranked Sparse

Summary

  • They share 2 benchmarks with published results for both. Claude Opus 5 scores higher in 1 category and Mercury 2.5 in 0 categories; one gap is clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5 leads 86.1 to 22.4.
  • The biggest single-benchmark swing is ProofBench: 99% for Claude Opus 5 and 3% for Mercury 2.5.
  • Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $5 / $25 for Claude Opus 5.
  • Claude Opus 5 accepts more context: 1M tokens versus 260K.

Side by side

Claude Opus 5Mercury 2.5
ProviderAnthropicInception
Noometry Index67.730.2
Released2026-07-242026-09-08
WeightsProprietaryProprietary
Context window1M260K
Max output128K66K
Input $ / M tokens$5$0.04
Output $ / M tokens$25$0.15
Results tracked572

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Category by category

Coding Not comparable

Claude Opus 5: 67.0 (#5), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
ALE-Bench2,165301.65
DeepSWE73.6%—
FrontierCode53.4%—
CursorBench46.6%—
LMArena WebDev1694—
FrontierSWE52%—
SciCode56.4%—
WeirdML91.8%—
LMArena Coding1533—

Agentic & Tool Use Not comparable

Claude Opus 5: 55.5 (#1), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
APEX-Agents65.8%—
OSWorld 2.031.4%—
τ²-bench Banking48.7%—
PostTrainBench35%—
BALROG63.4%—
GBAEval79.6%—
GDP.pdf24%—
Vending-Bench 211,182—

Reasoning Not comparable

Claude Opus 5: 77.1 (#3), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
ARC-AGI-290.4%—
SimpleBench80.6%—
NYT Connections (extended)94.3%—
ARC-AGI-197.5%—
CritPt29.1%—
Chess Puzzles42%—
EBR-Bench45.7%—
LMArena Hard Prompts1525—
Mystery Game Puzzles59%—
DTBench97.9%—
LMCA64.5%—
Bench to the Future 30.12—
Epoch Capabilities Index162.67—

Math Claude Opus 5 leads

Claude Opus 5: 86.1 (#6), Mercury 2.5: 22.4

BenchmarkClaude Opus 5Mercury 2.5
ProofBench99%3%
FrontierMath (Tiers 1-3)85.6%—
FrontierMath Tier 473.2%—
OTIS Mock AIME 2024-202598.9%—
LMArena Math1533—

Knowledge Not comparable

Claude Opus 5: 66.8 (#8), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
GPQA Diamond93.9%—
SimpleQA Verified59.9%—
LMArena Expert1558—

Multimodal Not comparable

Claude Opus 5: 51.1 (#6), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
LMArena Vision1321—
Blueprint-Bench 230.4%—
Furniture Assembly60.8%—
LMArena Document1516—

Multilingual Not comparable

Claude Opus 5: 58.8 (#3), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
LMArena Non-English1500—
LMArena Chinese1575—
LMArena French1522—
LMArena German1522—
LMArena Japanese1510—
LMArena Korean1526—
LMArena Russian1507—
LMArena Spanish1519—

Instruction Following Not comparable

Claude Opus 5: 79.3 (#5), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
LMArena Instruction Following1516—

Long Context Not comparable

Claude Opus 5: 46.5 (#20), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
LMArena Longer Query1516—

Writing & Preference Not comparable

Claude Opus 5: 79.3 (#2), Mercury 2.5: —

BenchmarkClaude Opus 5Mercury 2.5
LMArena Text1506—
LMArena Creative Writing1491—
EQ-Bench Creative Writing2133—
EQ-Bench 41385—
LMArena Multi-Turn1496—

Frequently asked questions

Is Claude Opus 5 better than Mercury 2.5?

Claude Opus 5 has enough public results to be ranked (#4); Mercury 2.5 does not yet, so treat this comparison as directional.

Which is cheaper, Claude Opus 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 Opus 5 lists at $5 and $25.

Which has the bigger context window?

Claude Opus 5 does, with 1M tokens against 260K.

How many benchmarks do Claude Opus 5 and Mercury 2.5 share?

2 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and Mercury 2.5 has 2.

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