Model comparison

Mercury 2.5 vs Qwen3.5-Flash

Qwen3.5-Flash is the stronger model overall, scoring 42.5 to 33.5 on the Noometry Index. Mercury 2.5 costs 2.6× less per token, which makes it the better buy when Qwen3.5-Flash's lead doesn't matter for your workload.

Last verified October 11, 2026. 1 shared benchmarks.

Mercury 2.5 Inception

33.5

Rank #242 Reported

Qwen3.5-Flash

Alibaba (Qwen)

42.5

Rank #112 Confirmed

Summary

They share 1 benchmark with published results for both. Mercury 2.5 scores higher in 1 category and Qwen3.5-Flash in 2 categories; 3 gaps are clear of the uncertainty.
The widest gap is in math, where Qwen3.5-Flash leads 37.4 to 23.3.
Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $0.10 / $0.40 for Qwen3.5-Flash.
Qwen3.5-Flash accepts more context: 1M tokens versus 260K.

Side by side

Mercury 2.5 and Qwen3.5-Flash specifications
	Mercury 2.5	Qwen3.5-Flash
Provider	Inception	Alibaba (Qwen)
Noometry Index	33.5	42.5
Released	2026-09-08	2026-02-23
Weights	Proprietary	Proprietary
Context window	260K	1M
Max output	66K	66K
Input $ / M tokens	$0.04	$0.10
Output $ / M tokens	$0.15	$0.40
Results tracked	4	32

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Category by category

Coding Mercury 2.5 leads

Mercury 2.5: 39.5 (#156), Qwen3.5-Flash: 34.2 (#242)

Coding benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
ALE-Bench	301.65	221.8
LMArena WebDev	—	1244
SciCode	38.5%	—
LMArena Coding	—	1412

Agentic & Tool Use Not comparable

Mercury 2.5: —, Qwen3.5-Flash: —

Agentic & Tool Use benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
Vending-Bench 2	—	462.69

Reasoning Qwen3.5-Flash leads

Mercury 2.5: 22.4 (#193), Qwen3.5-Flash: 33.7 (#72)

Reasoning benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
CritPt	0%	—
Chess Puzzles	—	21%
LMArena Hard Prompts	—	1403
Mystery Game Puzzles	—	20%
DTBench	—	82.9%
LMCA	—	29.1%
Epoch Capabilities Index	—	143.98

Math Qwen3.5-Flash leads

Mercury 2.5: 23.3 (#272), Qwen3.5-Flash: 37.4 (#158)

Math benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
FrontierMath (Tiers 1-3)	—	18.2%
OTIS Mock AIME 2024-2025	—	84.4%
ProofBench	3%	—
LMArena Math	—	1407
FrontierMath (Feb 2025 set)	—	6.2%
FrontierMath Tier 4 (v1)	—	0%

Knowledge Not comparable

Mercury 2.5: —, Qwen3.5-Flash: 43.2 (#93)

Knowledge benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
GPQA Diamond	—	82.3%
SimpleQA Verified	—	20.3%
Vectara Hallucination Rate	—	10.5%
LMArena Expert	—	1407

Multilingual Not comparable

Mercury 2.5: —, Qwen3.5-Flash: 50.5 (#121)

Multilingual benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
LMArena Non-English	—	1385
LMArena Chinese	—	1446
LMArena French	—	1412
LMArena German	—	1390
LMArena Japanese	—	1368
LMArena Korean	—	1344
LMArena Russian	—	1379
LMArena Spanish	—	1400

Instruction Following Not comparable

Mercury 2.5: —, Qwen3.5-Flash: 72.6 (#139)

Instruction Following benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
LMArena Instruction Following	—	1374

Long Context Not comparable

Mercury 2.5: —, Qwen3.5-Flash: 42.4 (#124)

Long Context benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
LMArena Longer Query	—	1392

Writing & Preference Not comparable

Mercury 2.5: —, Qwen3.5-Flash: 57.9 (#122)

Writing & Preference benchmarks
Benchmark	Mercury 2.5	Qwen3.5-Flash
LMArena Text	—	1397
LMArena Creative Writing	—	1343
LMArena Multi-Turn	—	1393

Frequently asked questions

Is Mercury 2.5 better than Qwen3.5-Flash?

Which is cheaper, Mercury 2.5 or Qwen3.5-Flash?

Mercury 2.5 is cheaper. It lists at $0.04 per million input tokens and $0.15 per million output tokens; Qwen3.5-Flash lists at $0.10 and $0.40.

Is Mercury 2.5 or Qwen3.5-Flash better for coding?

Mercury 2.5 scores higher on coding benchmarks: 39.5 versus 34.2 in the Noometry coding category.

Which has the bigger context window?

Qwen3.5-Flash does, with 1M tokens against 260K.

How many benchmarks do Mercury 2.5 and Qwen3.5-Flash share?

1 benchmark has published results for both models. Mercury 2.5 has 4 scored results on Noometry and Qwen3.5-Flash has 32.