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Model comparison

Qwen3.5 Flash vs Qwen3.5 Plus

Data verified

Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.

47.65/100
Margin
0.4pts
← winning
47.2/100
0 category wins1 category wins

Public leaderboard positions: Qwen3.5 Flash #134 (Supported); Qwen3.5 Plus #138 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Qwen3.5 Flash and Qwen3.5 Plus share 2 comparable benchmark results. 1 of 8 categories are comparable. 0 results are unique to Qwen3.5 Flash; 2 to Qwen3.5 Plus.

Updated July 23, 2026
Shared results
2
Qwen3.5 Flash only
0
Qwen3.5 Plus only
2
Comparable categories
1 / 8

Pick Qwen3.5 Flash if you want the stronger benchmark profile. Qwen3.5 Plus only becomes the better choice if mathematics is the priority.

Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 1 evidence category; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Qwen3.5 Flash has the cleaner BenchAlign overall profile here, landing at 47.65 versus 47.2. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Qwen3.5 Plus is also the more expensive model on tokens at $0.40 input / $2.40 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for Qwen3.5 Flash. That is roughly 6.0x on output cost alone.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Qwen3.5 Flash and Qwen3.5 Plus
CategoryQwen3.5 FlashΔQwen3.5 Plus
MathQwen3.5 Flash4.7Margin 11.6Qwen3.5 Plus16.3

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Qwen3.5 FlashB · Qwen3.5 Plus
  1. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 6.207%B 21.034%
    Winner: Qwen3.5 PlusΔ 14.8
    FrontierMath v2 (Tiers 1-3): Qwen3.5 Flash scored 6.207%; Qwen3.5 Plus scored 21.034%. Qwen3.5 Plus wins this benchmark.
  2. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 0.000%B 2.083%
    Winner: Qwen3.5 PlusΔ 2.1
    FrontierMath v2 (Tier 4): Qwen3.5 Flash scored 0.000%; Qwen3.5 Plus scored 2.083%. Qwen3.5 Plus wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricQwen3.5 FlashQwen3.5 PlusComparison
Input / output priceUSD per 1M tokensQwen3.5 Flash$0.1 input / $0.4 outputQwen3.5 Plus$0.4 input / $2.4 outputQwen3.5 Flash has the lower combined listed price.
Generation speedtokens per secondQwen3.5 FlashNot availableQwen3.5 PlusNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenQwen3.5 FlashNot availableQwen3.5 PlusNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensQwen3.5 Flash1MQwen3.5 Plus1MListed context windows are equal.

Benchmark Deep Dive

Agentic
BenchmarkQwen3.5 FlashQwen3.5 PlusResult
JobBenchSource 18.5%Not comparable
Coding
BenchmarkQwen3.5 FlashQwen3.5 PlusResult
Vibe Code BenchSource 15.74%Not comparable
MathQwen3.5 Plus wins
BenchmarkQwen3.5 FlashQwen3.5 PlusResult
FrontierMath v2 (Tiers 1-3)Source 6.207%21.034%Qwen3.5 Plus leads
FrontierMath v2 (Tier 4)Source 0.000%2.083%Qwen3.5 Plus leads
Frequently Asked Questions (2)

Which is better, Qwen3.5 Flash or Qwen3.5 Plus?

Qwen3.5 Flash is ahead on BenchLM's BenchAlign leaderboard, 47.65 to 47.2. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 6.207% and 21.034%.

Which is better for math, Qwen3.5 Flash or Qwen3.5 Plus?

Qwen3.5 Plus has the edge for math in this comparison, averaging 16.3 versus 4.7. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.

Related Comparisons

Last updated: July 23, 2026

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