Compare/gpt-oss-20b (low) vs Qwen3.5 9B (Reasoning)

gpt-oss-20b (low)vsQwen3.5 9B (Reasoning)

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

OpenAI

gpt-oss-20b (low)

Input
$0.07/M
Output
$0.2/M
Speed
170 tok/s
TTFT
1.08s
Alibaba

Qwen3.5 9B (Reasoning)

Input
$0.14/M
Output
$0.2/M
Speed
81 tok/s
TTFT
2.07s

Winner by Category

Cheaper
gpt-oss-20b (low)
Faster (tok/s)
gpt-oss-20b (low)
Lower Latency
gpt-oss-20b (low)
Benchmarks (0-2)
Qwen3.5 9B (Reasoning)

Pricing Comparison

Metricgpt-oss-20b (low)Qwen3.5 9B (Reasoning)
Input ($/M tokens)$0.07$0.14
Output ($/M tokens)$0.2$0.2
Cost for 1M input + 100K output tokens:
gpt-oss-20b (low)$0.09
Qwen3.5 9B (Reasoning)$0.16

Speed Comparison

Output Speed (tokens/s) — higher is better
gpt-oss-20b (low)
170 tok/s
Qwen3.5 9B (Reasoning)
81 tok/s
Time to First Token (seconds) — lower is better
gpt-oss-20b (low)
1.08s
Qwen3.5 9B (Reasoning)
2.07s

Editorial Analysis

Verdict. Qwen3.5 9B (Reasoning) takes the aggregate benchmark matchup 2–0 across 2 categories. Real workloads usually care about a handful of specific tasks — see the per-benchmark table above.

Pricing. Both models sit in the budget bracket for output-token pricing. At 1.0× the per-million-token cost, Qwen3.5 9B (Reasoning) is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). Qwen3.5 9B (Reasoning) makes more sense when output volume is low and absolute reasoning quality justifies the premium.

Strengths. gpt-oss-20b (low) is strongest on Intelligence Index (14.4). Qwen3.5 9B (Reasoning) leads on Coding Index (28.7), Intelligence Index (21.8).

Speed. On throughput, gpt-oss-20b (low) generates tokens at 170 tok/s versus 81 tok/s — about 53% faster. On time-to-first-token, gpt-oss-20b (low) responds in 1080ms vs 2070ms, which matters most for chat-style UIs.

Provider. OpenAI and Alibaba sell to overlapping but distinct developer audiences: OpenAI tends to ship frontier reasoning models with premium positioning, while Alibaba often prices more aggressively. Your existing vendor relationships, billing, and SLA preferences may matter as much as the raw numbers above.

Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): gpt-oss-20b (low) costs $5.10 ($61/year); Qwen3.5 9B (Reasoning) costs $7.20 ($86/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): gpt-oss-20b (low) ≈ $0.75/run, Qwen3.5 9B (Reasoning) ≈ $1.10/run. At agent/realtime scale (200M input / 100M output per million requests): gpt-oss-20b (low) ≈ $34/run, Qwen3.5 9B (Reasoning) ≈ $48/run. gpt-oss-20b (low) becomes more attractive at higher volume — the absolute per-token pricing difference compounds when you ship at scale.

Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.

Head-to-head deltas

  • On throughput, gpt-oss-20b (low) is 2.11× faster (170 tok/s vs 81 tok/s). For streaming chat or real-time agents this alone often flips the recommendation.

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
14.421.8
Coding Index
28.7
Math Index
GPQA Diamond
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
SciCode
IFBench
TerminalBench
gpt-oss-20b (low)0 wins
2 winsQwen3.5 9B (Reasoning)

Frequently Asked Questions

Which is cheaper, gpt-oss-20b (low) or Qwen3.5 9B (Reasoning)?

gpt-oss-20b (low) is cheaper overall. Its blended price (3:1 input/output ratio) is $0.10/M tokens vs $0.15/M for Qwen3.5 9B (Reasoning).

Which model performs better on benchmarks?

Qwen3.5 9B (Reasoning) wins 2 out of 12 benchmarks compared to 0 for gpt-oss-20b (low). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

gpt-oss-20b (low) generates tokens faster at 170 tok/s vs 81 tok/s. gpt-oss-20b (low) also has lower time-to-first-token (1.08s vs 2.07s).

When should I use gpt-oss-20b (low) vs Qwen3.5 9B (Reasoning)?

Choose based on your priorities: gpt-oss-20b (low) for lower cost, Qwen3.5 9B (Reasoning) for stronger benchmark performance, and gpt-oss-20b (low) for faster generation. For latency-sensitive apps, check the TTFT comparison above.