Noometry

Model comparison

Grok 4.3 vs Mercury 2

Grok 4.3 is the stronger model overall, scoring 43.8 to 39.1 on the Noometry Index. Mercury 2 costs 4.2× less per token, which makes it the better buy when Grok 4.3's lead doesn't matter for your workload.

Last verified . 16 shared benchmarks.

Grok 4.3 xAI

43.8

Rank #86 Confirmed

Mercury 2 Inception

39.1

Rank #175 Confirmed

Summary

  • They share 16 benchmarks with published results for both. Grok 4.3 scores higher in 7 categories and Mercury 2 in 0 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Grok 4.3 leads 52.5 to 36.2.
  • The biggest single-benchmark swing is SciCode: 47.3% for Grok 4.3 and 38.7% for Mercury 2.
  • Mercury 2 is cheaper at $0.25 / $0.75 per million input/output tokens, against $1.25 / $2.50 for Grok 4.3.
  • Grok 4.3 accepts more context: 1M tokens versus 128K.

Side by side

Grok 4.3Mercury 2
ProviderxAIInception
Noometry Index43.839.1
Released2026-04-172026-02-20
WeightsProprietaryProprietary
Context window1M128K
Max output30K50K
Input $ / M tokens$1.25$0.25
Output $ / M tokens$2.50$0.75
Results tracked4017

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Category by category

Coding Grok 4.3 leads

Grok 4.3: 41.6 (#121), Mercury 2: 33.5 (#255)

BenchmarkGrok 4.3Mercury 2
LMArena WebDev13571171
SciCode47.3%38.7%
WeirdML49.9%43.2%
LMArena Coding14151391
ALE-Bench944.17785.58

Agentic & Tool Use Not comparable

Grok 4.3: 27.7 (#99), Mercury 2: —

BenchmarkGrok 4.3Mercury 2
GDP.pdf8%—
LMArena Search1165—
Vending-Bench 235.26—

Reasoning Grok 4.3 leads

Grok 4.3: 35.9 (#68), Mercury 2: 23.8 (#170)

BenchmarkGrok 4.3Mercury 2
CritPt8%0.8%
LMArena Hard Prompts13961362
NYT Connections (extended)55.2%—
Chess Puzzles25%—
DTBench90.7%—
LMCA38.3%—
Epoch Capabilities Index149.16—
ForecastBench60.3—

Math Not comparable

Grok 4.3: 46.0 (#74), Mercury 2: —

BenchmarkGrok 4.3Mercury 2
FrontierMath (Tiers 1-3)42.8%—
FrontierMath Tier 414.6%—
OTIS Mock AIME 2024-202593.3%—
ProofBench11%—
LMArena Math1388—

Knowledge Grok 4.3 leads

Grok 4.3: 52.5 (#62), Mercury 2: 36.2 (#172)

BenchmarkGrok 4.3Mercury 2
LMArena Expert13851358
GPQA Diamond88.8%—
SimpleQA Verified33.2%—
Vectara Hallucination Rate—12.3%

Multimodal Not comparable

Grok 4.3: 31.6 (#104), Mercury 2: —

BenchmarkGrok 4.3Mercury 2
LMArena Vision1229—
Blueprint-Bench 20%—

Multilingual Grok 4.3 leads

Grok 4.3: 50.5 (#120), Mercury 2: 46.6 (#157)

BenchmarkGrok 4.3Mercury 2
LMArena Non-English13851331
LMArena Chinese14221417
LMArena Russian13991304
LMArena French1412—
LMArena German1395—
LMArena Japanese1379—
LMArena Korean1356—
LMArena Spanish1398—

Instruction Following Grok 4.3 leads

Grok 4.3: 72.1 (#140), Mercury 2: 70.2 (#165)

BenchmarkGrok 4.3Mercury 2
LMArena Instruction Following13661329

Long Context Grok 4.3 leads

Grok 4.3: 42.5 (#123), Mercury 2: 40.5 (#154)

BenchmarkGrok 4.3Mercury 2
LMArena Longer Query13931330

Writing & Preference Grok 4.3 leads

Grok 4.3: 58.5 (#118), Mercury 2: 53.8 (#155)

BenchmarkGrok 4.3Mercury 2
LMArena Text13971355
LMArena Creative Writing13801289
LMArena Multi-Turn14061358
EQ-Bench 41075—

Frequently asked questions

Is Grok 4.3 better than Mercury 2?

Grok 4.3 is the stronger model overall, scoring 43.8 to 39.1 on the Noometry Index. Mercury 2 costs 4.2× less per token, which makes it the better buy when Grok 4.3's lead doesn't matter for your workload.

Which is cheaper, Grok 4.3 or Mercury 2?

Mercury 2 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; Grok 4.3 lists at $1.25 and $2.50.

Is Grok 4.3 or Mercury 2 better for coding?

Grok 4.3 scores higher on coding benchmarks: 41.6 versus 33.5 in the Noometry coding category.

Which has the bigger context window?

Grok 4.3 does, with 1M tokens against 128K.

How many benchmarks do Grok 4.3 and Mercury 2 share?

16 benchmarks have published results for both models. Grok 4.3 has 40 scored results on Noometry and Mercury 2 has 17.

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