GPT-5 Mini vs Qwen3.5 Flash

Two models head to head

GPT-5 Mini and Qwen3.5 Flash are two budget models, built for high volumes at a low price, one from OpenAI, the other from Alibaba Cloud (Qwen). GPT-5 Mini was released on August 7, 2025, Qwen3.5 Flash on February 23, 2026.

All figures below come from public sources checked on October 22, 2026: models.dev and OpenRouter for prices and capabilities, Epoch AI for scores.

What the benchmarks say

On our capability index, GPT-5 Mini scores 62.9 out of 100 and Qwen3.5 Flash 62.6. The gap is too small to separate them.

On the 3 benchmarks reported for both, GPT-5 Mini wins 2 times and Qwen3.5 Flash 1:

• GPQA Diamond (PhD-level science questions): GPT-5 Mini 75%, Qwen3.5 Flash 82.3%
• OTIS Mock AIME (competition mathematics problems): GPT-5 Mini 86.7%, Qwen3.5 Flash 84.4%
• FrontierMath (very hard research-level mathematics): GPT-5 Mini 46.7%, Qwen3.5 Flash 18.2%

Pricing

GPT-5 Mini costs $0.25 per million input tokens and $2 per million output tokens; Qwen3.5 Flash costs $0.10 and $0.40.

For a typical agent task (read 20,000 tokens, write 2,000), expect $0.009 with GPT-5 Mini versus $0.003 with Qwen3.5 Flash. Qwen3.5 Flash is 3.2 times cheaper, a gap that adds up quickly over 1,000 tasks: $6.2 difference.

Run the numbers with your own volumes in the agent cost calculator.

Under the hood

Qwen3.5 Flash reads more in one go: 1,000,000 tokens of context (roughly 1,500 pages), versus 272,000 for GPT-5 Mini.

Reasoning mode: GPT-5 Mini yes, Qwen3.5 Flash yes. Tool calling: GPT-5 Mini yes, Qwen3.5 Flash yes. Image input: GPT-5 Mini yes, Qwen3.5 Flash yes.

Neither publishes its weights: both are used through an API.

In short

Our reading of the data:

• Choose Qwen3.5 Flash for a lower cost, a larger context window and a more recent release.

This verdict relies on public figures; it does not replace a trial on your own tasks.