Noometry

Model comparison

Gemini 3.8 Flash vs Mercury 2.5

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 33.5 on the Noometry Index. Mercury 2.5 costs 22× less per token, which makes it the better buy when Gemini 3.8 Flash's lead doesn't matter for your workload.

Last verified . 4 shared benchmarks.

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

Mercury 2.5 Inception

33.5

Rank #242 Reported

Summary

  • They share 4 benchmarks with published results for both. Gemini 3.8 Flash scores higher in 3 categories and Mercury 2.5 in 0 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.8 Flash leads 76.9 to 22.4.
  • The biggest single-benchmark swing is ProofBench: 48% for Gemini 3.8 Flash and 3% for Mercury 2.5.
  • Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $0.75 / $3.75 for Gemini 3.8 Flash.
  • Gemini 3.8 Flash accepts more context: 1.05M tokens versus 260K.

Side by side

Gemini 3.8 FlashMercury 2.5
ProviderGoogleInception
Noometry Index61.833.5
Released2026-09-022026-09-08
WeightsProprietaryProprietary
Context window1.05M260K
Max output66K66K
Input $ / M tokens$0.75$0.04
Output $ / M tokens$3.75$0.15
Results tracked504

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Category by category

Coding Gemini 3.8 Flash leads

Gemini 3.8 Flash: 59.2 (#15), Mercury 2.5: 39.5 (#156)

BenchmarkGemini 3.8 FlashMercury 2.5
SciCode56.6%38.5%
ALE-Bench1,270301.65
DeepSWE73.8%—
FrontierCode41.2%—
CursorBench39.6%—
LMArena WebDev1584—
FrontierSWE19.6%—
WeirdML84.8%—
LMArena Coding1510—

Agentic & Tool Use Not comparable

Gemini 3.8 Flash: 41.8 (#21), Mercury 2.5: —

BenchmarkGemini 3.8 FlashMercury 2.5
APEX-Agents64.3%—
Remote Labor Index5.8%—
GDP.pdf23.4%—
Vending-Bench 25,094—

Reasoning Gemini 3.8 Flash leads

Gemini 3.8 Flash: 76.9 (#5), Mercury 2.5: 22.4 (#193)

BenchmarkGemini 3.8 FlashMercury 2.5
CritPt18.3%0%
ARC-AGI-289.2%—
NYT Connections (extended)97.4%—
ARC-AGI-198.5%—
Chess Puzzles61%—
LMArena Hard Prompts1508—
Mystery Game Puzzles47%—
DTBench95.7%—
LMCA52.9%—
Surface Evolver Bench76.9%—
Epoch Capabilities Index156.71—

Math Gemini 3.8 Flash leads

Gemini 3.8 Flash: 65.3 (#28), Mercury 2.5: 23.3 (#272)

BenchmarkGemini 3.8 FlashMercury 2.5
ProofBench48%3%
FrontierMath (Tiers 1-3)68.4%—
FrontierMath Tier 422%—
OTIS Mock AIME 2024-202598.9%—
LMArena Math1528—

Knowledge Not comparable

Gemini 3.8 Flash: 74.8 (#2), Mercury 2.5: —

BenchmarkGemini 3.8 FlashMercury 2.5
GPQA Diamond95.4%—
Humanity's Last Exam44.5%—
SimpleQA Verified69.7%—
LMArena Expert1524—

Multimodal Not comparable

Gemini 3.8 Flash: 40.7 (#45), Mercury 2.5: —

BenchmarkGemini 3.8 FlashMercury 2.5
LMArena Vision1314—
Blueprint-Bench 238.6%—
Furniture Assembly31.7%—

Multilingual Not comparable

Gemini 3.8 Flash: 58.0 (#5), Mercury 2.5: —

BenchmarkGemini 3.8 FlashMercury 2.5
LMArena Non-English1491—
LMArena Chinese1554—
LMArena French1498—
LMArena German1493—
LMArena Japanese1502—
LMArena Korean1459—
LMArena Russian1515—
LMArena Spanish1485—

Instruction Following Not comparable

Gemini 3.8 Flash: 78.0 (#13), Mercury 2.5: —

BenchmarkGemini 3.8 FlashMercury 2.5
LMArena Instruction Following1490—

Long Context Not comparable

Gemini 3.8 Flash: 46.3 (#24), Mercury 2.5: —

BenchmarkGemini 3.8 FlashMercury 2.5
LMArena Longer Query1508—

Writing & Preference Not comparable

Gemini 3.8 Flash: 72.2 (#15), Mercury 2.5: —

BenchmarkGemini 3.8 FlashMercury 2.5
LMArena Text1499—
LMArena Creative Writing1492—
EQ-Bench Creative Writing1748—
LMArena Multi-Turn1501—

Frequently asked questions

Is Gemini 3.8 Flash better than Mercury 2.5?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 33.5 on the Noometry Index. Mercury 2.5 costs 22× less per token, which makes it the better buy when Gemini 3.8 Flash's lead doesn't matter for your workload.

Which is cheaper, Gemini 3.8 Flash 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; Gemini 3.8 Flash lists at $0.75 and $3.75.

Is Gemini 3.8 Flash or Mercury 2.5 better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 39.5 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 260K.

How many benchmarks do Gemini 3.8 Flash and Mercury 2.5 share?

4 benchmarks have published results for both models. Gemini 3.8 Flash has 50 scored results on Noometry and Mercury 2.5 has 4.

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